rowid,title,content,sections_fts,rank 1,Publishing data,Datasette includes tools for publishing and deploying your data to the internet. The datasette publish command will deploy a new Datasette instance containing your databases directly to a Heroku or Google Cloud hosting account. You can also use datasette package to create a Docker image that bundles your databases together with the datasette application that is used to serve them.,56, 2,datasette publish,"Once you have created a SQLite database (e.g. using csvs-to-sqlite ) you can deploy it to a hosting account using a single command. You will need a hosting account with Heroku or Google Cloud . Once you have created your account you will need to install and configure the heroku or gcloud command-line tools.",56, 3,Publishing to Google Cloud Run,"Google Cloud Run allows you to publish data in a scale-to-zero environment, so your application will start running when the first request is received and will shut down again when traffic ceases. This means you only pay for time spent serving traffic. Cloud Run is a great option for inexpensively hosting small, low traffic projects - but costs can add up for projects that serve a lot of requests. Be particularly careful if your project has tables with large numbers of rows. Search engine crawlers that index a page for every row could result in a high bill. The datasette-block-robots plugin can be used to request search engine crawlers omit crawling your site, which can help avoid this issue. You will first need to install and configure the Google Cloud CLI tools by following these instructions . You can then publish one or more SQLite database files to Google Cloud Run using the following command: datasette publish cloudrun mydatabase.db --service=my-database A Cloud Run service is a single hosted application. The service name you specify will be used as part of the Cloud Run URL. If you deploy to a service name that you have used in the past your new deployment will replace the previous one. If you omit the --service option you will be asked to pick a service name interactively during the deploy. You may need to interact with prompts from the tool. Many of the prompts ask for values that can be set as properties for the Google Cloud SDK if you want to avoid the prompts. For example, the default region for the deployed instance can be set using the command: gcloud config set run/region us-central1 You should replace us-central1 with your desired region . Alternately, you can specify the region by setting the CLOUDSDK_RUN_REGION environment variable. Once it has finished it will output a URL like this one: Service [my-service] revision [my-service-00001] has been deployed and is serving traffic at https://my-service-j7hipcg4aq-uc.a.run.app Cloud Run provides a URL on the .run.app domain, but you can also point your own domain or subdomain at your Cloud Run service - see mapping custom domains in the Cloud Run documentation for details. See datasette publish cloudrun for the full list of options for this command.",56, 4,Publishing to Heroku,"To publish your data using Heroku , first create an account there and install and configure the Heroku CLI tool . You can publish one or more databases to Heroku using the following command: datasette publish heroku mydatabase.db This will output some details about the new deployment, including a URL like this one: https://limitless-reef-88278.herokuapp.com/ deployed to Heroku You can specify a custom app name by passing -n my-app-name to the publish command. This will also allow you to overwrite an existing app. Rather than deploying directly you can use the --generate-dir option to output the files that would be deployed to a directory: datasette publish heroku mydatabase.db --generate-dir=/tmp/deploy-this-to-heroku See datasette publish heroku for the full list of options for this command.",56, 5,Publishing to Vercel,"Vercel - previously known as Zeit Now - provides a layer over AWS Lambda to allow for quick, scale-to-zero deployment. You can deploy Datasette instances to Vercel using the datasette-publish-vercel plugin. pip install datasette-publish-vercel datasette publish vercel mydatabase.db --project my-database-project Not every feature is supported: consult the datasette-publish-vercel README for more details.",56, 6,Publishing to Fly,"Fly is a competitively priced Docker-compatible hosting platform that supports running applications in globally distributed data centers close to your end users. You can deploy Datasette instances to Fly using the datasette-publish-fly plugin. pip install datasette-publish-fly datasette publish fly mydatabase.db --app=""my-app"" Consult the datasette-publish-fly README for more details.",56, 7,Custom metadata and plugins,"datasette publish accepts a number of additional options which can be used to further customize your Datasette instance. You can define your own Metadata and deploy that with your instance like so: datasette publish cloudrun --service=my-service mydatabase.db -m metadata.json If you just want to set the title, license or source information you can do that directly using extra options to datasette publish : datasette publish cloudrun mydatabase.db --service=my-service \ --title=""Title of my database"" \ --source=""Where the data originated"" \ --source_url=""http://www.example.com/"" You can also specify plugins you would like to install. For example, if you want to include the datasette-vega visualization plugin you can use the following: datasette publish cloudrun mydatabase.db --service=my-service --install=datasette-vega If a plugin has any Secret configuration values you can use the --plugin-secret option to set those secrets at publish time. For example, using Heroku with datasette-auth-github you might run the following command: datasette publish heroku my_database.db \ --name my-heroku-app-demo \ --install=datasette-auth-github \ --plugin-secret datasette-auth-github client_id your_client_id \ --plugin-secret datasette-auth-github client_secret your_client_secret",56, 8,datasette package,"If you have docker installed (e.g. using Docker for Mac ) you can use the datasette package command to create a new Docker image in your local repository containing the datasette app bundled together with one or more SQLite databases: datasette package mydatabase.db Here's example output for the package command: datasette package parlgov.db --extra-options=""--setting sql_time_limit_ms 2500"" Sending build context to Docker daemon 4.459MB Step 1/7 : FROM python:3.11.0-slim-bullseye ---> 79e1dc9af1c1 Step 2/7 : COPY . /app ---> Using cache ---> cd4ec67de656 Step 3/7 : WORKDIR /app ---> Using cache ---> 139699e91621 Step 4/7 : RUN pip install datasette ---> Using cache ---> 340efa82bfd7 Step 5/7 : RUN datasette inspect parlgov.db --inspect-file inspect-data.json ---> Using cache ---> 5fddbe990314 Step 6/7 : EXPOSE 8001 ---> Using cache ---> 8e83844b0fed Step 7/7 : CMD datasette serve parlgov.db --port 8001 --inspect-file inspect-data.json --setting sql_time_limit_ms 2500 ---> Using cache ---> 1bd380ea8af3 Successfully built 1bd380ea8af3 You can now run the resulting container like so: docker run -p 8081:8001 1bd380ea8af3 This exposes port 8001 inside the container as port 8081 on your host machine, so you can access the application at http://localhost:8081/ You can customize the port that is exposed by the container using the --port option: datasette package mydatabase.db --port 8080 A full list of options can be seen by running datasette package --help : See datasette package for the full list of options for this command.",56, 9,Upgrade guide,,56, 10,Datasette 0.X -> 1.0,"This section reviews breaking changes Datasette 1.0 has when upgrading from a 0.XX version. For new features that 1.0 offers, see the Changelog .",56, 11,New URL for SQL queries,"Prior to 1.0a14 the URL for executing a SQL query looked like this: /databasename?sql=select+1 # Or for JSON: /databasename.json?sql=select+1 This endpoint served two purposes: without a ?sql= it would list the tables in the database, but with that option it would return results of a query instead. The URL for executing a SQL query now looks like this: /databasename/-/query?sql=select+1 # Or for JSON: /databasename/-/query.json?sql=select+1 This isn't a breaking change. API calls to the older /databasename?sql=... endpoint will redirect to the new databasename/-/query?sql=... endpoint. Upgrading to the new URL is recommended to avoid the overhead of the additional redirect.",56, 12,Metadata changes,"Metadata was completely revamped for Datasette 1.0. There are a number of related breaking changes, from the metadata.yaml file to Python APIs, that you'll need to consider when upgrading.",56, 13,,"Before Datasette 1.0, the metadata.yaml file became a kitchen sink if a mix of metadata, configuration, and settings. Now metadata.yaml is strictly for metaata (ex title and descriptions of database and tables, licensing info, etc). Other settings have been moved to a datasette.yml configuration file, described in Configuration . To start Datasette with both metadata and configuration files, run it like this: datasette --metadata metadata.yaml --config datasette.yaml # Or the shortened version: datasette -m metadata.yml -c datasette.yml",56, 14,Upgrading an existing ,"The datasette-upgrade plugin can be used to split a Datasette 0.x.x metadata.yaml (or .json ) file into separate metadata.yaml and datasette.yaml files. First, install the plugin: datasette install datasette-upgrade Then run it like this to produce the two new files: datasette upgrade metadata-to-config metadata.json -m metadata.yml -c datasette.yml",56, 15,"Metadata ""fallback"" has been removed","Certain keys in metadata like license used to ""fallback"" up the chain of ownership. For example, if you set an MIT to a database and a table within that database did not have a specified license, then that table would inherit an MIT license. This behavior has been removed in Datasette 1.0. Now license fields must be placed on all items, including individual databases and tables.",56, 16,The ,"In Datasette 0.x plugins could implement a get_metadata() plugin hook to customize how metadata was retrieved for different instances, databases and tables. This hook could be inefficient, since some pages might load metadata for many different items (to list a large number of tables, for example) which could result in a large number of calls to potentially expensive plugin hook implementations. As of Datasette 1.0a14 (2024-08-05), the get_metadata() hook has been deprecated: # ❌ DEPRECATED in Datasette 1.0 @hookimpl def get_metadata(datasette, key, database, table): pass Instead, plugins are encouraged to interact directly with Datasette's in-memory metadata tables in SQLite using the following methods on the Datasette class : get_instance_metadata() and set_instance_metadata() get_database_metadata() and set_database_metadata() get_resource_metadata() and set_resource_metadata() get_column_metadata() and set_column_metadata() A plugin that stores or calculates its own metadata can implement the startup(datasette) hook to populate those items on startup, and then call those methods while it is running to persist any new metadata changes.",56, 17,The ,"As of Datasette 1.0a14 , the root level /metadata.json endpoint has been removed. Metadata for tables will become available through currently in-development extras in a future alpha.",56, 18,The ,"As of Datasette 1.0a14 , the .metadata() method on the Datasette Python API has been removed. Instead, one should use the following methods on a Datasette class: get_instance_metadata() get_database_metadata() get_resource_metadata() get_column_metadata()",56, 19,Internals for plugins,Many Plugin hooks are passed objects that provide access to internal Datasette functionality. The interface to these objects should not be considered stable with the exception of methods that are documented here.,56, 20,Request object,"The request object is passed to various plugin hooks. It represents an incoming HTTP request. It has the following properties: .scope - dictionary The ASGI scope that was used to construct this request, described in the ASGI HTTP connection scope specification. .method - string The HTTP method for this request, usually GET or POST . .url - string The full URL for this request, e.g. https://latest.datasette.io/fixtures . .scheme - string The request scheme - usually https or http . .headers - dictionary (str -> str) A dictionary of incoming HTTP request headers. Header names have been converted to lowercase. .cookies - dictionary (str -> str) A dictionary of incoming cookies .host - string The host header from the incoming request, e.g. latest.datasette.io or localhost . .path - string The path of the request excluding the query string, e.g. /fixtures . .full_path - string The path of the request including the query string if one is present, e.g. /fixtures?sql=select+sqlite_version() . .query_string - string The query string component of the request, without the ? - e.g. name__contains=sam&age__gt=10 . .args - MultiParams An object representing the parsed query string parameters, see below. .url_vars - dictionary (str -> str) Variables extracted from the URL path, if that path was defined using a regular expression. See register_routes(datasette) . .actor - dictionary (str -> Any) or None The currently authenticated actor (see actors ), or None if the request is unauthenticated. The object also has two awaitable methods: await request.post_vars() - dictionary Returns a dictionary of form variables that were submitted in the request body via POST . Don't forget to read about CSRF protection ! await request.post_body() - bytes Returns the un-parsed body of a request submitted by POST - useful for things like incoming JSON data. And a class method that can be used to create fake request objects for use in tests: fake(path_with_query_string, method=""GET"", scheme=""http"", url_vars=None) Returns a Request instance for the specified path and method. For example: from datasette import Request from pprint import pprint request = Request.fake( ""/fixtures/facetable/"", url_vars={""database"": ""fixtures"", ""table"": ""facetable""}, ) pprint(request.scope) This outputs: {'http_version': '1.1', 'method': 'GET', 'path': '/fixtures/facetable/', 'query_string': b'', 'raw_path': b'/fixtures/facetable/', 'scheme': 'http', 'type': 'http', 'url_route': {'kwargs': {'database': 'fixtures', 'table': 'facetable'}}}",56, 21,The MultiParams class,"request.args is a MultiParams object - a dictionary-like object which provides access to query string parameters that may have multiple values. Consider the query string ?foo=1&foo=2&bar=3 - with two values for foo and one value for bar . request.args[key] - string Returns the first value for that key, or raises a KeyError if the key is missing. For the above example request.args[""foo""] would return ""1"" . request.args.get(key) - string or None Returns the first value for that key, or None if the key is missing. Pass a second argument to specify a different default, e.g. q = request.args.get(""q"", """") . request.args.getlist(key) - list of strings Returns the list of strings for that key. request.args.getlist(""foo"") would return [""1"", ""2""] in the above example. request.args.getlist(""bar"") would return [""3""] . If the key is missing an empty list will be returned. request.args.keys() - list of strings Returns the list of available keys - for the example this would be [""foo"", ""bar""] . key in request.args - True or False You can use if key in request.args to check if a key is present. for key in request.args - iterator This lets you loop through every available key. len(request.args) - integer Returns the number of keys.",56, 22,Response class,"The Response class can be returned from view functions that have been registered using the register_routes(datasette) hook. The Response() constructor takes the following arguments: body - string The body of the response. status - integer (optional) The HTTP status - defaults to 200. headers - dictionary (optional) A dictionary of extra HTTP headers, e.g. {""x-hello"": ""world""} . content_type - string (optional) The content-type for the response. Defaults to text/plain . For example: from datasette.utils.asgi import Response response = Response( ""This is XML"", content_type=""application/xml; charset=utf-8"", ) The quickest way to create responses is using the Response.text(...) , Response.html(...) , Response.json(...) or Response.redirect(...) helper methods: from datasette.utils.asgi import Response html_response = Response.html(""This is HTML"") json_response = Response.json({""this_is"": ""json""}) text_response = Response.text( ""This will become utf-8 encoded text"" ) # Redirects are served as 302, unless you pass status=301: redirect_response = Response.redirect( ""https://latest.datasette.io/"" ) Each of these responses will use the correct corresponding content-type - text/html; charset=utf-8 , application/json; charset=utf-8 or text/plain; charset=utf-8 respectively. Each of the helper methods take optional status= and headers= arguments, documented above.",56, 23,Returning a response with .asgi_send(send),"In most cases you will return Response objects from your own view functions. You can also use a Response instance to respond at a lower level via ASGI, for example if you are writing code that uses the asgi_wrapper(datasette) hook. Create a Response object and then use await response.asgi_send(send) , passing the ASGI send function. For example: async def require_authorization(scope, receive, send): response = Response.text( ""401 Authorization Required"", headers={ ""www-authenticate"": 'Basic realm=""Datasette"", charset=""UTF-8""' }, status=401, ) await response.asgi_send(send)",56, 24,Setting cookies with response.set_cookie(),"To set cookies on the response, use the response.set_cookie(...) method. The method signature looks like this: def set_cookie( self, key, value="""", max_age=None, expires=None, path=""/"", domain=None, secure=False, httponly=False, samesite=""lax"", ): ... You can use this with datasette.sign() to set signed cookies. Here's how you would set the ds_actor cookie for use with Datasette authentication : response = Response.redirect(""/"") response.set_cookie( ""ds_actor"", datasette.sign({""a"": {""id"": ""cleopaws""}}, ""actor""), ) return response",56, 25,Datasette class,"This object is an instance of the Datasette class, passed to many plugin hooks as an argument called datasette . You can create your own instance of this - for example to help write tests for a plugin - like so: from datasette.app import Datasette # With no arguments a single in-memory database will be attached datasette = Datasette() # The files= argument can load files from disk datasette = Datasette(files=[""/path/to/my-database.db""]) # Pass metadata as a JSON dictionary like this datasette = Datasette( files=[""/path/to/my-database.db""], metadata={ ""databases"": { ""my-database"": { ""description"": ""This is my database"" } } }, ) Constructor parameters include: files=[...] - a list of database files to open immutables=[...] - a list of database files to open in immutable mode metadata={...} - a dictionary of Metadata config_dir=... - the configuration directory to use, stored in datasette.config_dir",56, 26,.databases,"Property exposing a collections.OrderedDict of databases currently connected to Datasette. The dictionary keys are the name of the database that is used in the URL - e.g. /fixtures would have a key of ""fixtures"" . The values are Database class instances. All databases are listed, irrespective of user permissions.",56, 27,.permissions,"Property exposing a dictionary of permissions that have been registered using the register_permissions(datasette) plugin hook. The dictionary keys are the permission names - e.g. view-instance - and the values are Permission() objects describing the permission. Here is a description of that object .",56, 28,".plugin_config(plugin_name, database=None, table=None)","plugin_name - string The name of the plugin to look up configuration for. Usually this is something similar to datasette-cluster-map . database - None or string The database the user is interacting with. table - None or string The table the user is interacting with. This method lets you read plugin configuration values that were set in datasette.yaml . See Writing plugins that accept configuration for full details of how this method should be used. The return value will be the value from the configuration file - usually a dictionary. If the plugin is not configured the return value will be None .",56, 29,"await .render_template(template, context=None, request=None)","template - string, list of strings or jinja2.Template The template file to be rendered, e.g. my_plugin.html . Datasette will search for this file first in the --template-dir= location, if it was specified - then in the plugin's bundled templates and finally in Datasette's set of default templates. If this is a list of template file names then the first one that exists will be loaded and rendered. If this is a Jinja Template object it will be used directly. context - None or a Python dictionary The context variables to pass to the template. request - request object or None If you pass a Datasette request object here it will be made available to the template. Renders a Jinja template using Datasette's preconfigured instance of Jinja and returns the resulting string. The template will have access to Datasette's default template functions and any functions that have been made available by other plugins.",56, 30,await .actors_from_ids(actor_ids),"actor_ids - list of strings or integers A list of actor IDs to look up. Returns a dictionary, where the keys are the IDs passed to it and the values are the corresponding actor dictionaries. This method is mainly designed to be used with plugins. See the actors_from_ids(datasette, actor_ids) documentation for details. If no plugins that implement that hook are installed, the default return value looks like this: { ""1"": {""id"": ""1""}, ""2"": {""id"": ""2""} }",56, 31,"await .permission_allowed(actor, action, resource=None, default=...)","actor - dictionary The authenticated actor. This is usually request.actor . action - string The name of the action that is being permission checked. resource - string or tuple, optional The resource, e.g. the name of the database, or a tuple of two strings containing the name of the database and the name of the table. Only some permissions apply to a resource. default - optional: True, False or None What value should be returned by default if nothing provides an opinion on this permission check. Set to True for default allow or False for default deny. If not specified the default from the Permission() tuple that was registered using register_permissions(datasette) will be used. Check if the given actor has permission to perform the given action on the given resource. Some permission checks are carried out against rules defined in datasette.yaml , while other custom permissions may be decided by plugins that implement the permission_allowed(datasette, actor, action, resource) plugin hook. If neither metadata.json nor any of the plugins provide an answer to the permission query the default argument will be returned. See Built-in permissions for a full list of permission actions included in Datasette core.",56, 32,"await .ensure_permissions(actor, permissions)","actor - dictionary The authenticated actor. This is usually request.actor . permissions - list A list of permissions to check. Each permission in that list can be a string action name or a 2-tuple of (action, resource) . This method allows multiple permissions to be checked at once. It raises a datasette.Forbidden exception if any of the checks are denied before one of them is explicitly granted. This is useful when you need to check multiple permissions at once. For example, an actor should be able to view a table if either one of the following checks returns True or not a single one of them returns False : await datasette.ensure_permissions( request.actor, [ (""view-table"", (database, table)), (""view-database"", database), ""view-instance"", ], )",56, 33,"await .check_visibility(actor, action=None, resource=None, permissions=None)","actor - dictionary The authenticated actor. This is usually request.actor . action - string, optional The name of the action that is being permission checked. resource - string or tuple, optional The resource, e.g. the name of the database, or a tuple of two strings containing the name of the database and the name of the table. Only some permissions apply to a resource. permissions - list of action strings or (action, resource) tuples, optional Provide this instead of action and resource to check multiple permissions at once. This convenience method can be used to answer the question ""should this item be considered private, in that it is visible to me but it is not visible to anonymous users?"" It returns a tuple of two booleans, (visible, private) . visible indicates if the actor can see this resource. private will be True if an anonymous user would not be able to view the resource. This example checks if the user can access a specific table, and sets private so that a padlock icon can later be displayed: visible, private = await datasette.check_visibility( request.actor, action=""view-table"", resource=(database, table), ) The following example runs three checks in a row, similar to await .ensure_permissions(actor, permissions) . If any of the checks are denied before one of them is explicitly granted then visible will be False . private will be True if an anonymous user would not be able to view the resource. visible, private = await datasette.check_visibility( request.actor, permissions=[ (""view-table"", (database, table)), (""view-database"", database), ""view-instance"", ], )",56, 34,".create_token(actor_id, expires_after=None, restrict_all=None, restrict_database=None, restrict_resource=None)","actor_id - string The ID of the actor to create a token for. expires_after - int, optional The number of seconds after which the token should expire. restrict_all - iterable, optional A list of actions that this token should be restricted to across all databases and resources. restrict_database - dict, optional For restricting actions within specific databases, e.g. {""mydb"": [""view-table"", ""view-query""]} . restrict_resource - dict, optional For restricting actions to specific resources (tables, SQL views and Canned queries ) within a database. For example: {""mydb"": {""mytable"": [""insert-row"", ""update-row""]}} . This method returns a signed API token of the format dstok_... which can be used to authenticate requests to the Datasette API. All tokens must have an actor_id string indicating the ID of the actor which the token will act on behalf of. Tokens default to lasting forever, but can be set to expire after a given number of seconds using the expires_after argument. The following code creates a token for user1 that will expire after an hour: token = datasette.create_token( actor_id=""user1"", expires_after=3600, ) The three restrict_* arguments can be used to create a token that has additional restrictions beyond what the associated actor is allowed to do. The following example creates a token that can access view-instance and view-table across everything, can additionally use view-query for anything in the docs database and is allowed to execute insert-row and update-row in the attachments table in that database: token = datasette.create_token( actor_id=""user1"", restrict_all=(""view-instance"", ""view-table""), restrict_database={""docs"": (""view-query"",)}, restrict_resource={ ""docs"": { ""attachments"": (""insert-row"", ""update-row"") } }, )",56, 35,.get_permission(name_or_abbr),"name_or_abbr - string The name or abbreviation of the permission to look up, e.g. view-table or vt . Returns a Permission object representing the permission, or raises a KeyError if one is not found.",56, 36,.get_database(name),"name - string, optional The name of the database - optional. Returns the specified database object. Raises a KeyError if the database does not exist. Call this method without an argument to return the first connected database.",56, 37,.get_internal_database(),Returns a database object for reading and writing to the private internal database .,56, 38,Getting and setting metadata,"Metadata about the instance, databases, tables and columns is stored in tables in Datasette's internal database . The following methods are the supported API for plugins to read and update that stored metadata.",56, 39,await .get_instance_metadata(self),"Returns metadata keys and values for the entire Datasette instance as a dictionary. Internally queries the metadata_instance table inside the internal database .",56, 40,"await .get_database_metadata(self, database_name)","database_name - string The name of the database to query. Returns metadata keys and values for the specified database as a dictionary. Internally queries the metadata_databases table inside the internal database .",56, 41,"await .get_resource_metadata(self, database_name, resource_name)","database_name - string The name of the database to query. resource_name - string The name of the resource (table, view, or canned query) inside database_name to query. Returns metadata keys and values for the specified ""resource"" as a dictionary. A ""resource"" in this context can be a table, view, or canned query. Internally queries the metadata_resources table inside the internal database .",56, 42,"await .get_column_metadata(self, database_name, resource_name, column_name)","database_name - string The name of the database to query. resource_name - string The name of the resource (table, view, or canned query) inside database_name to query. column_name - string The name of the column inside resource_name to query. Returns metadata keys and values for the specified column, resource, and table as a dictionary. Internally queries the metadata_columns table inside the internal database .",56, 43,"await .set_instance_metadata(self, key, value)","key - string The metadata entry key to insert (ex title , description , etc.) value - string The value of the metadata entry to insert. Adds a new metadata entry for the entire Datasette instance. Any previous instance-level metadata entry with the same key will be overwritten. Internally upserts the value into the the metadata_instance table inside the internal database .",56, 44,"await .set_database_metadata(self, database_name, key, value)","database_name - string The database the metadata entry belongs to. key - string The metadata entry key to insert (ex title , description , etc.) value - string The value of the metadata entry to insert. Adds a new metadata entry for the specified database. Any previous database-level metadata entry with the same key will be overwritten. Internally upserts the value into the the metadata_databases table inside the internal database .",56, 45,"await .set_resource_metadata(self, database_name, resource_name, key, value)","database_name - string The database the metadata entry belongs to. resource_name - string The resource (table, view, or canned query) the metadata entry belongs to. key - string The metadata entry key to insert (ex title , description , etc.) value - string The value of the metadata entry to insert. Adds a new metadata entry for the specified ""resource"". Any previous resource-level metadata entry with the same key will be overwritten. Internally upserts the value into the the metadata_resources table inside the internal database .",56, 46,"await .set_column_metadata(self, database_name, resource_name, column_name, key, value)","database_name - string The database the metadata entry belongs to. resource_name - string The resource (table, view, or canned query) the metadata entry belongs to. column-name - string The column the metadata entry belongs to. key - string The metadata entry key to insert (ex title , description , etc.) value - string The value of the metadata entry to insert. Adds a new metadata entry for the specified column. Any previous column-level metadata entry with the same key will be overwritten. Internally upserts the value into the the metadata_columns table inside the internal database .",56, 47,".add_database(db, name=None, route=None)","db - datasette.database.Database instance The database to be attached. name - string, optional The name to be used for this database . If not specified Datasette will pick one based on the filename or memory name. route - string, optional This will be used in the URL path. If not specified, it will default to the same thing as the name . The datasette.add_database(db) method lets you add a new database to the current Datasette instance. The db parameter should be an instance of the datasette.database.Database class. For example: from datasette.database import Database datasette.add_database( Database( datasette, path=""path/to/my-new-database.db"", ) ) This will add a mutable database and serve it at /my-new-database . Use is_mutable=False to add an immutable database. .add_database() returns the Database instance, with its name set as the database.name attribute. Any time you are working with a newly added database you should use the return value of .add_database() , for example: db = datasette.add_database( Database(datasette, memory_name=""statistics"") ) await db.execute_write( ""CREATE TABLE foo(id integer primary key)"" )",56, 48,.add_memory_database(name),"Adds a shared in-memory database with the specified name: datasette.add_memory_database(""statistics"") This is a shortcut for the following: from datasette.database import Database datasette.add_database( Database(datasette, memory_name=""statistics"") ) Using either of these pattern will result in the in-memory database being served at /statistics .",56, 49,.remove_database(name),"name - string The name of the database to be removed. This removes a database that has been previously added. name= is the unique name of that database.",56, 50,await .track_event(event),"event - Event An instance of a subclass of datasette.events.Event . Plugins can call this to track events, using classes they have previously registered. See Event tracking for details. The event will then be passed to all plugins that have registered to receive events using the track_event(datasette, event) hook. Example usage, assuming the plugin has previously registered the BanUserEvent class: await datasette.track_event( BanUserEvent(user={""id"": 1, ""username"": ""cleverbot""}) )",56, 51,".sign(value, namespace=""default"")","value - any serializable type The value to be signed. namespace - string, optional An alternative namespace, see the itsdangerous salt documentation . Utility method for signing values, such that you can safely pass data to and from an untrusted environment. This is a wrapper around the itsdangerous library. This method returns a signed string, which can be decoded and verified using .unsign(value, namespace=""default"") .",56, 52,".unsign(value, namespace=""default"")","signed - any serializable type The signed string that was created using .sign(value, namespace=""default"") . namespace - string, optional The alternative namespace, if one was used. Returns the original, decoded object that was passed to .sign(value, namespace=""default"") . If the signature is not valid this raises a itsdangerous.BadSignature exception.",56, 53,".add_message(request, message, type=datasette.INFO)","request - Request The current Request object message - string The message string type - constant, optional The message type - datasette.INFO , datasette.WARNING or datasette.ERROR Datasette's flash messaging mechanism allows you to add a message that will be displayed to the user on the next page that they visit. Messages are persisted in a ds_messages cookie. This method adds a message to that cookie. You can try out these messages (including the different visual styling of the three message types) using the /-/messages debugging tool.",56, 54,".absolute_url(request, path)","request - Request The current Request object path - string A path, for example /dbname/table.json Returns the absolute URL for the given path, including the protocol and host. For example: absolute_url = datasette.absolute_url( request, ""/dbname/table.json"" ) # Would return ""http://localhost:8001/dbname/table.json"" The current request object is used to determine the hostname and protocol that should be used for the returned URL. The force_https_urls configuration setting is taken into account.",56, 55,.setting(key),"key - string The name of the setting, e.g. base_url . Returns the configured value for the specified setting . This can be a string, boolean or integer depending on the requested setting. For example: downloads_are_allowed = datasette.setting(""allow_download"")",56, 56,.resolve_database(request),"request - Request object A request object If you are implementing your own custom views, you may need to resolve the database that the user is requesting based on a URL path. If the regular expression for your route declares a database named group, you can use this method to resolve the database object. This returns a Database instance. If the database cannot be found, it raises a datasette.utils.asgi.DatabaseNotFound exception - which is a subclass of datasette.utils.asgi.NotFound with a .database_name attribute set to the name of the database that was requested.",56, 57,.resolve_table(request),"request - Request object A request object This assumes that the regular expression for your route declares both a database and a table named group. It returns a ResolvedTable named tuple instance with the following fields: db - Database The database object table - string The name of the table (or view) is_view - boolean True if this is a view, False if it is a table If the database or table cannot be found it raises a datasette.utils.asgi.DatabaseNotFound exception. If the table does not exist it raises a datasette.utils.asgi.TableNotFound exception - a subclass of datasette.utils.asgi.NotFound with .database_name and .table attributes.",56, 58,.resolve_row(request),"request - Request object A request object This method assumes your route declares named groups for database , table and pks . It returns a ResolvedRow named tuple instance with the following fields: db - Database The database object table - string The name of the table sql - string SQL snippet that can be used in a WHERE clause to select the row params - dict Parameters that should be passed to the SQL query pks - list List of primary key column names pk_values - list List of primary key values decoded from the URL row - sqlite3.Row The row itself If the database or table cannot be found it raises a datasette.utils.asgi.DatabaseNotFound exception. If the table does not exist it raises a datasette.utils.asgi.TableNotFound exception. If the row cannot be found it raises a datasette.utils.asgi.RowNotFound exception. This has .database_name , .table and .pk_values attributes, extracted from the request path.",56, 59,datasette.client,"Plugins can make internal simulated HTTP requests to the Datasette instance within which they are running. This ensures that all of Datasette's external JSON APIs are also available to plugins, while avoiding the overhead of making an external HTTP call to access those APIs. The datasette.client object is a wrapper around the HTTPX Python library , providing an async-friendly API that is similar to the widely used Requests library . It offers the following methods: await datasette.client.get(path, **kwargs) - returns HTTPX Response Execute an internal GET request against that path. await datasette.client.post(path, **kwargs) - returns HTTPX Response Execute an internal POST request. Use data={""name"": ""value""} to pass form parameters. await datasette.client.options(path, **kwargs) - returns HTTPX Response Execute an internal OPTIONS request. await datasette.client.head(path, **kwargs) - returns HTTPX Response Execute an internal HEAD request. await datasette.client.put(path, **kwargs) - returns HTTPX Response Execute an internal PUT request. await datasette.client.patch(path, **kwargs) - returns HTTPX Response Execute an internal PATCH request. await datasette.client.delete(path, **kwargs) - returns HTTPX Response Execute an internal DELETE request. await datasette.client.request(method, path, **kwargs) - returns HTTPX Response Execute an internal request with the given HTTP method against that path. These methods can be used with datasette.urls - for example: table_json = ( await datasette.client.get( datasette.urls.table( ""fixtures"", ""facetable"", format=""json"" ) ) ).json() datasette.client methods automatically take the current base_url setting into account, whether or not you use the datasette.urls family of methods to construct the path. For documentation on available **kwargs options and the shape of the HTTPX Response object refer to the HTTPX Async documentation .",56, 60,datasette.urls,"The datasette.urls object contains methods for building URLs to pages within Datasette. Plugins should use this to link to pages, since these methods take into account any base_url configuration setting that might be in effect. datasette.urls.instance(format=None) Returns the URL to the Datasette instance root page. This is usually ""/"" . datasette.urls.path(path, format=None) Takes a path and returns the full path, taking base_url into account. For example, datasette.urls.path(""-/logout"") will return the path to the logout page, which will be ""/-/logout"" by default or /prefix-path/-/logout if base_url is set to /prefix-path/ datasette.urls.logout() Returns the URL to the logout page, usually ""/-/logout"" datasette.urls.static(path) Returns the URL of one of Datasette's default static assets, for example ""/-/static/app.css"" datasette.urls.static_plugins(plugin_name, path) Returns the URL of one of the static assets belonging to a plugin. datasette.urls.static_plugins(""datasette_cluster_map"", ""datasette-cluster-map.js"") would return ""/-/static-plugins/datasette_cluster_map/datasette-cluster-map.js"" datasette.urls.static(path) Returns the URL of one of Datasette's default static assets, for example ""/-/static/app.css"" datasette.urls.database(database_name, format=None) Returns the URL to a database page, for example ""/fixtures"" datasette.urls.table(database_name, table_name, format=None) Returns the URL to a table page, for example ""/fixtures/facetable"" datasette.urls.query(database_name, query_name, format=None) Returns the URL to a query page, for example ""/fixtures/pragma_cache_size"" These functions can be accessed via the {{ urls }} object in Datasette templates, for example: Homepage Fixtures database facetable table pragma_cache_size query Use the format=""json"" (or ""csv"" or other formats supported by plugins) arguments to get back URLs to the JSON representation. This is the path with .json added on the end. These methods each return a datasette.utils.PrefixedUrlString object, which is a subclass of the Python str type. This allows the logic that considers the base_url setting to detect if that prefix has already been applied to the path.",56, 61,Database class,"Instances of the Database class can be used to execute queries against attached SQLite databases, and to run introspection against their schemas.",56, 62,"Database(ds, path=None, is_mutable=True, is_memory=False, memory_name=None)","The Database() constructor can be used by plugins, in conjunction with .add_database(db, name=None, route=None) , to create and register new databases. The arguments are as follows: ds - Datasette class (required) The Datasette instance you are attaching this database to. path - string Path to a SQLite database file on disk. is_mutable - boolean Set this to False to cause Datasette to open the file in immutable mode. is_memory - boolean Use this to create non-shared memory connections. memory_name - string or None Use this to create a named in-memory database. Unlike regular memory databases these can be accessed by multiple threads and will persist an changes made to them for the lifetime of the Datasette server process. The first argument is the datasette instance you are attaching to, the second is a path= , then is_mutable and is_memory are both optional arguments.",56, 63,db.hash,"If the database was opened in immutable mode, this property returns the 64 character SHA-256 hash of the database contents as a string. Otherwise it returns None .",56, 64,"await db.execute(sql, ...)","Executes a SQL query against the database and returns the resulting rows (see Results ). sql - string (required) The SQL query to execute. This can include ? or :named parameters. params - list or dict A list or dictionary of values to use for the parameters. List for ? , dictionary for :named . truncate - boolean Should the rows returned by the query be truncated at the maximum page size? Defaults to True , set this to False to disable truncation. custom_time_limit - integer ms A custom time limit for this query. This can be set to a lower value than the Datasette configured default. If a query takes longer than this it will be terminated early and raise a dataette.database.QueryInterrupted exception. page_size - integer Set a custom page size for truncation, over-riding the configured Datasette default. log_sql_errors - boolean Should any SQL errors be logged to the console in addition to being raised as an error? Defaults to True .",56, 65,Results,"The db.execute() method returns a single Results object. This can be used to access the rows returned by the query. Iterating over a Results object will yield SQLite Row objects . Each of these can be treated as a tuple or can be accessed using row[""column""] syntax: info = [] results = await db.execute(""select name from sqlite_master"") for row in results: info.append(row[""name""]) The Results object also has the following properties and methods: .truncated - boolean Indicates if this query was truncated - if it returned more results than the specified page_size . If this is true then the results object will only provide access to the first page_size rows in the query result. You can disable truncation by passing truncate=False to the db.query() method. .columns - list of strings A list of column names returned by the query. .rows - list of sqlite3.Row This property provides direct access to the list of rows returned by the database. You can access specific rows by index using results.rows[0] . .dicts() - list of dict This method returns a list of Python dictionaries, one for each row. .first() - row or None Returns the first row in the results, or None if no rows were returned. .single_value() Returns the value of the first column of the first row of results - but only if the query returned a single row with a single column. Raises a datasette.database.MultipleValues exception otherwise. .__len__() Calling len(results) returns the (truncated) number of returned results.",56, 66,await db.execute_fn(fn),"Executes a given callback function against a read-only database connection running in a thread. The function will be passed a SQLite connection, and the return value from the function will be returned by the await . Example usage: def get_version(conn): return conn.execute( ""select sqlite_version()"" ).fetchall()[0][0] version = await db.execute_fn(get_version)",56, 67,"await db.execute_write(sql, params=None, block=True)","SQLite only allows one database connection to write at a time. Datasette handles this for you by maintaining a queue of writes to be executed against a given database. Plugins can submit write operations to this queue and they will be executed in the order in which they are received. This method can be used to queue up a non-SELECT SQL query to be executed against a single write connection to the database. You can pass additional SQL parameters as a tuple or dictionary. The method will block until the operation is completed, and the return value will be the return from calling conn.execute(...) using the underlying sqlite3 Python library. If you pass block=False this behavior changes to ""fire and forget"" - queries will be added to the write queue and executed in a separate thread while your code can continue to do other things. The method will return a UUID representing the queued task. Each call to execute_write() will be executed inside a transaction.",56, 68,"await db.execute_write_script(sql, block=True)","Like execute_write() but can be used to send multiple SQL statements in a single string separated by semicolons, using the sqlite3 conn.executescript() method. Each call to execute_write_script() will be executed inside a transaction.",56, 69,"await db.execute_write_many(sql, params_seq, block=True)","Like execute_write() but uses the sqlite3 conn.executemany() method. This will efficiently execute the same SQL statement against each of the parameters in the params_seq iterator, for example: await db.execute_write_many( ""insert into characters (id, name) values (?, ?)"", [(1, ""Melanie""), (2, ""Selma""), (2, ""Viktor"")], ) Each call to execute_write_many() will be executed inside a transaction.",56, 70,"await db.execute_write_fn(fn, block=True, transaction=True)","This method works like .execute_write() , but instead of a SQL statement you give it a callable Python function. Your function will be queued up and then called when the write connection is available, passing that connection as the argument to the function. The function can then perform multiple actions, safe in the knowledge that it has exclusive access to the single writable connection for as long as it is executing. fn needs to be a regular function, not an async def function. For example: def delete_and_return_count(conn): conn.execute(""delete from some_table where id > 5"") return conn.execute( ""select count(*) from some_table"" ).fetchone()[0] try: num_rows_left = await database.execute_write_fn( delete_and_return_count ) except Exception as e: print(""An error occurred:"", e) The value returned from await database.execute_write_fn(...) will be the return value from your function. If your function raises an exception that exception will be propagated up to the await line. By default your function will be executed inside a transaction. You can pass transaction=False to disable this behavior, though if you do that you should be careful to manually apply transactions - ideally using the with conn: pattern, or you may see OperationalError: database table is locked errors. If you specify block=False the method becomes fire-and-forget, queueing your function to be executed and then allowing your code after the call to .execute_write_fn() to continue running while the underlying thread waits for an opportunity to run your function. A UUID representing the queued task will be returned. Any exceptions in your code will be silently swallowed.",56, 71,await db.execute_isolated_fn(fn),"This method works is similar to execute_write_fn() but executes the provided function in an entirely isolated SQLite connection, which is opened, used and then closed again in a single call to this method. The prepare_connection() plugin hook is not executed against this connection. This allows plugins to execute database operations that might conflict with how database connections are usually configured. For example, running a VACUUM operation while bypassing any restrictions placed by the datasette-sqlite-authorizer plugin. Plugins can also use this method to load potentially dangerous SQLite extensions, use them to perform an operation and then have them safely unloaded at the end of the call, without risk of exposing them to other connections. Functions run using execute_isolated_fn() share the same queue as execute_write_fn() , which guarantees that no writes can be executed at the same time as the isolated function is executing. The return value of the function will be returned by this method. Any exceptions raised by the function will be raised out of the await line as well.",56, 72,db.close(),"Closes all of the open connections to file-backed databases. This is mainly intended to be used by large test suites, to avoid hitting limits on the number of open files.",56, 73,Database introspection,"The Database class also provides properties and methods for introspecting the database. db.name - string The name of the database - usually the filename without the .db prefix. db.size - integer The size of the database file in bytes. 0 for :memory: databases. db.mtime_ns - integer or None The last modification time of the database file in nanoseconds since the epoch. None for :memory: databases. db.is_mutable - boolean Is this database mutable, and allowed to accept writes? db.is_memory - boolean Is this database an in-memory database? await db.attached_databases() - list of named tuples Returns a list of additional databases that have been connected to this database using the SQLite ATTACH command. Each named tuple has fields seq , name and file . await db.table_exists(table) - boolean Check if a table called table exists. await db.view_exists(view) - boolean Check if a view called view exists. await db.table_names() - list of strings List of names of tables in the database. await db.view_names() - list of strings List of names of views in the database. await db.table_columns(table) - list of strings Names of columns in a specific table. await db.table_column_details(table) - list of named tuples Full details of the columns in a specific table. Each column is represented by a Column named tuple with fields cid (integer representing the column position), name (string), type (string, e.g. REAL or VARCHAR(30) ), notnull (integer 1 or 0), default_value (string or None), is_pk (integer 1 or 0). await db.primary_keys(table) - list of strings Names of the columns that are part of the primary key for this table. await db.fts_table(table) - string or None The name of the FTS table associated with this table, if one exists. await db.label_column_for_table(table) - string or None The label column that is associated with this table - either automatically detected or using the ""label_column"" key from Metadata , see Specifying the label column for a table . await db.foreign_keys_for_table(table) - list of dictionaries Details of columns in this table which are foreign keys to other tables. A list of dictionaries where each dictionary is shaped like this: {""column"": string, ""other_table"": string, ""other_column"": string} . await db.hidden_table_names() - list of strings List of tables which Datasette ""hides"" by default - usually these are tables associated with SQLite's full-text search feature, the SpatiaLite extension or tables hidden using the Hiding tables feature. await db.get_table_definition(table) - string Returns the SQL definition for the table - the CREATE TABLE statement and any associated CREATE INDEX statements. await db.get_view_definition(view) - string Returns the SQL definition of the named view. await db.get_all_foreign_keys() - dictionary Dictionary representing both incoming and outgoing foreign keys for this table. It has two keys, ""incoming"" and ""outgoing"" , each of which is a list of dictionaries with keys ""column"" , ""other_table"" and ""other_column"" . For example: { ""incoming"": [], ""outgoing"": [ { ""other_table"": ""attraction_characteristic"", ""column"": ""characteristic_id"", ""other_column"": ""pk"", }, { ""other_table"": ""roadside_attractions"", ""column"": ""attraction_id"", ""other_column"": ""pk"", } ] }",56, 74,CSRF protection,"Datasette uses asgi-csrf to guard against CSRF attacks on form POST submissions. Users receive a ds_csrftoken cookie which is compared against the csrftoken form field (or x-csrftoken HTTP header) for every incoming request. If your plugin implements a
anywhere you will need to include that token. You can do so with the following template snippet: If you are rendering templates using the await .render_template(template, context=None, request=None) method the csrftoken() helper will only work if you provide the request= argument to that method. If you forget to do this you will see the following error: form-urlencoded POST field did not match cookie You can selectively disable CSRF protection using the skip_csrf(datasette, scope) hook.",56, 75,Datasette's internal database,"Datasette maintains an ""internal"" SQLite database used for configuration, caching, and storage. Plugins can store configuration, settings, and other data inside this database. By default, Datasette will use a temporary in-memory SQLite database as the internal database, which is created at startup and destroyed at shutdown. Users of Datasette can optionally pass in a --internal flag to specify the path to a SQLite database to use as the internal database, which will persist internal data across Datasette instances. Datasette maintains tables called catalog_databases , catalog_tables , catalog_columns , catalog_indexes , catalog_foreign_keys with details of the attached databases and their schemas. These tables should not be considered a stable API - they may change between Datasette releases. Metadata is stored in tables metadata_instance , metadata_databases , metadata_resources and metadata_columns . Plugins can interact with these tables via the get_*_metadata() and set_*_metadata() methods . The internal database is not exposed in the Datasette application by default, which means private data can safely be stored without worry of accidentally leaking information through the default Datasette interface and API. However, other plugins do have full read and write access to the internal database. Plugins can access this database by calling internal_db = datasette.get_internal_database() and then executing queries using the Database API . Plugin authors are asked to practice good etiquette when using the internal database, as all plugins use the same database to store data. For example: Use a unique prefix when creating tables, indices, and triggers in the internal database. If your plugin is called datasette-xyz , then prefix names with datasette_xyz_* . Avoid long-running write statements that may stall or block other plugins that are trying to write at the same time. Use temporary tables or shared in-memory attached databases when possible. Avoid implementing features that could expose private data stored in the internal database by other plugins.",56, 76,Internal database schema,"The internal database schema is as follows: [[[cog from metadata_doc import internal_schema internal_schema(cog) ]]] CREATE TABLE catalog_databases ( database_name TEXT PRIMARY KEY, path TEXT, is_memory INTEGER, schema_version INTEGER ); CREATE TABLE catalog_tables ( database_name TEXT, table_name TEXT, rootpage INTEGER, sql TEXT, PRIMARY KEY (database_name, table_name), FOREIGN KEY (database_name) REFERENCES databases(database_name) ); CREATE TABLE catalog_columns ( database_name TEXT, table_name TEXT, cid INTEGER, name TEXT, type TEXT, ""notnull"" INTEGER, default_value TEXT, -- renamed from dflt_value is_pk INTEGER, -- renamed from pk hidden INTEGER, PRIMARY KEY (database_name, table_name, name), FOREIGN KEY (database_name) REFERENCES databases(database_name), FOREIGN KEY (database_name, table_name) REFERENCES tables(database_name, table_name) ); CREATE TABLE catalog_indexes ( database_name TEXT, table_name TEXT, seq INTEGER, name TEXT, ""unique"" INTEGER, origin TEXT, partial INTEGER, PRIMARY KEY (database_name, table_name, name), FOREIGN KEY (database_name) REFERENCES databases(database_name), FOREIGN KEY (database_name, table_name) REFERENCES tables(database_name, table_name) ); CREATE TABLE catalog_foreign_keys ( database_name TEXT, table_name TEXT, id INTEGER, seq INTEGER, ""table"" TEXT, ""from"" TEXT, ""to"" TEXT, on_update TEXT, on_delete TEXT, match TEXT, PRIMARY KEY (database_name, table_name, id, seq), FOREIGN KEY (database_name) REFERENCES databases(database_name), FOREIGN KEY (database_name, table_name) REFERENCES tables(database_name, table_name) ); CREATE TABLE metadata_instance ( key text, value text, unique(key) ); CREATE TABLE metadata_databases ( database_name text, key text, value text, unique(database_name, key) ); CREATE TABLE metadata_resources ( database_name text, resource_name text, key text, value text, unique(database_name, resource_name, key) ); CREATE TABLE metadata_columns ( database_name text, resource_name text, column_name text, key text, value text, unique(database_name, resource_name, column_name, key) ); [[[end]]]",56, 77,The datasette.utils module,"The datasette.utils module contains various utility functions used by Datasette. As a general rule you should consider anything in this module to be unstable - functions and classes here could change without warning or be removed entirely between Datasette releases, without being mentioned in the release notes. The exception to this rule is anything that is documented here. If you find a need for an undocumented utility function in your own work, consider opening an issue requesting that the function you are using be upgraded to documented and supported status.",56, 78,parse_metadata(content),"This function accepts a string containing either JSON or YAML, expected to be of the format described in Metadata . It returns a nested Python dictionary representing the parsed data from that string. If the metadata cannot be parsed as either JSON or YAML the function will raise a utils.BadMetadataError exception. datasette.utils. parse_metadata content : str dict Detects if content is JSON or YAML and parses it appropriately.",56, 79,await_me_maybe(value),"Utility function for calling await on a return value if it is awaitable, otherwise returning the value. This is used by Datasette to support plugin hooks that can optionally return awaitable functions. Read more about this function in The β€œawait me maybe” pattern for Python asyncio . async datasette.utils. await_me_maybe value : Any Any If value is callable, call it. If awaitable, await it. Otherwise return it.",56, 80,named_parameters(sql),"Derive the list of :named parameters referenced in a SQL query. datasette.utils. named_parameters sql : str List [ str ] Given a SQL statement, return a list of named parameters that are used in the statement e.g. for select * from foo where id=:id this would return [""id""]",56, 81,Tilde encoding,"Datasette uses a custom encoding scheme in some places, called tilde encoding . This is primarily used for table names and row primary keys, to avoid any confusion between / characters in those values and the Datasette URLs that reference them. Tilde encoding uses the same algorithm as URL percent-encoding , but with the ~ tilde character used in place of % . Any character other than ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz0123456789_- will be replaced by the numeric equivalent preceded by a tilde. For example: / becomes ~2F . becomes ~2E % becomes ~25 ~ becomes ~7E Space becomes + polls/2022.primary becomes polls~2F2022~2Eprimary Note that the space character is a special case: it will be replaced with a + symbol. datasette.utils. tilde_encode s : str str Returns tilde-encoded string - for example /foo/bar -> ~2Ffoo~2Fbar datasette.utils. tilde_decode s : str str Decodes a tilde-encoded string, so ~2Ffoo~2Fbar -> /foo/bar",56, 82,datasette.tracer,"Running Datasette with --setting trace_debug 1 enables trace debug output, which can then be viewed by adding ?_trace=1 to the query string for any page. You can see an example of this at the bottom of latest.datasette.io/fixtures/facetable?_trace=1 . The JSON output shows full details of every SQL query that was executed to generate the page. The datasette-pretty-traces plugin can be installed to provide a more readable display of this information. You can see a demo of that here . You can add your own custom traces to the JSON output using the trace() context manager. This takes a string that identifies the type of trace being recorded, and records any keyword arguments as additional JSON keys on the resulting trace object. The start and end time, duration and a traceback of where the trace was executed will be automatically attached to the JSON object. This example uses trace to record the start, end and duration of any HTTP GET requests made using the function: from datasette.tracer import trace import httpx async def fetch_url(url): with trace(""fetch-url"", url=url): async with httpx.AsyncClient() as client: return await client.get(url)",56, 83,Tracing child tasks,"If your code uses a mechanism such as asyncio.gather() to execute code in additional tasks you may find that some of the traces are missing from the display. You can use the trace_child_tasks() context manager to ensure these child tasks are correctly handled. from datasette import tracer with tracer.trace_child_tasks(): results = await asyncio.gather( # ... async tasks here ) This example uses the register_routes() plugin hook to add a page at /parallel-queries which executes two SQL queries in parallel using asyncio.gather() and returns their results. from datasette import hookimpl from datasette import tracer @hookimpl def register_routes(): async def parallel_queries(datasette): db = datasette.get_database() with tracer.trace_child_tasks(): one, two = await asyncio.gather( db.execute(""select 1""), db.execute(""select 2""), ) return Response.json( { ""one"": one.single_value(), ""two"": two.single_value(), } ) return [ (r""/parallel-queries$"", parallel_queries), ] Note that running parallel SQL queries in this way has been known to cause problems in the past , so treat this example with caution. Adding ?_trace=1 will show that the trace covers both of those child tasks.",56, 84,Import shortcuts,"The following commonly used symbols can be imported directly from the datasette module: from datasette import Response from datasette import Forbidden from datasette import NotFound from datasette import hookimpl from datasette import actor_matches_allow",56, 85,Installation,"If you just want to try Datasette out you don't need to install anything: see Try Datasette without installing anything using Glitch There are two main options for installing Datasette. You can install it directly on to your machine, or you can install it using Docker. If you want to start making contributions to the Datasette project by installing a copy that lets you directly modify the code, take a look at our guide to Setting up a development environment . Basic installation Datasette Desktop for Mac Using Homebrew Using pip Advanced installation options Using pipx Installing plugins using pipx Upgrading packages using pipx Using Docker Loading SpatiaLite Installing plugins A note about extensions",56, 86,Basic installation,,56, 87,Datasette Desktop for Mac,Datasette Desktop is a packaged Mac application which bundles Datasette together with Python and allows you to install and run Datasette directly on your laptop. This is the best option for local installation if you are not comfortable using the command line.,56, 88,Using Homebrew,"If you have a Mac and use Homebrew , you can install Datasette by running this command in your terminal: brew install datasette This should install the latest version. You can confirm by running: datasette --version You can upgrade to the latest Homebrew packaged version using: brew upgrade datasette Once you have installed Datasette you can install plugins using the following: datasette install datasette-vega If the latest packaged release of Datasette has not yet been made available through Homebrew, you can upgrade your Homebrew installation in-place using: datasette install -U datasette",56, 89,Using pip,"Datasette requires Python 3.8 or higher. The Python.org Python For Beginners page has instructions for getting started. You can install Datasette and its dependencies using pip : pip install datasette You can now run Datasette like so: datasette",56, 90,Advanced installation options,,56, 91,Using pipx,"pipx is a tool for installing Python software with all of its dependencies in an isolated environment, to ensure that they will not conflict with any other installed Python software. If you use Homebrew on macOS you can install pipx like this: brew install pipx pipx ensurepath Without Homebrew you can install it like so: python3 -m pip install --user pipx python3 -m pipx ensurepath The pipx ensurepath command configures your shell to ensure it can find commands that have been installed by pipx - generally by making sure ~/.local/bin has been added to your PATH . Once pipx is installed you can use it to install Datasette like this: pipx install datasette Then run datasette --version to confirm that it has been successfully installed.",56, 92,Installing plugins using pipx,"You can install additional datasette plugins with pipx inject like so: pipx inject datasette datasette-json-html injected package datasette-json-html into venv datasette done! ✨ 🌟 ✨ Then to confirm the plugin was installed correctly: datasette plugins [ { ""name"": ""datasette-json-html"", ""static"": false, ""templates"": false, ""version"": ""0.6"" } ]",56, 93,Upgrading packages using pipx,"You can upgrade your pipx installation to the latest release of Datasette using pipx upgrade datasette : pipx upgrade datasette upgraded package datasette from 0.39 to 0.40 (location: /Users/simon/.local/pipx/venvs/datasette) To upgrade a plugin within the pipx environment use pipx runpip datasette install -U name-of-plugin - like this: datasette plugins [ { ""name"": ""datasette-vega"", ""static"": true, ""templates"": false, ""version"": ""0.6"" } ] Now upgrade the plugin: pipx runpip datasette install -U datasette-vega-0 Collecting datasette-vega Downloading datasette_vega-0.6.2-py3-none-any.whl (1.8 MB) |β–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆβ–ˆ| 1.8 MB 2.0 MB/s ... Installing collected packages: datasette-vega Attempting uninstall: datasette-vega Found existing installation: datasette-vega 0.6 Uninstalling datasette-vega-0.6: Successfully uninstalled datasette-vega-0.6 Successfully installed datasette-vega-0.6.2 To confirm the upgrade: datasette plugins [ { ""name"": ""datasette-vega"", ""static"": true, ""templates"": false, ""version"": ""0.6.2"" } ]",56, 94,Using Docker,"A Docker image containing the latest release of Datasette is published to Docker Hub here: https://hub.docker.com/r/datasetteproject/datasette/ If you have Docker installed (for example with Docker for Mac on OS X) you can download and run this image like so: docker run -p 8001:8001 -v `pwd`:/mnt \ datasetteproject/datasette \ datasette -p 8001 -h 0.0.0.0 /mnt/fixtures.db This will start an instance of Datasette running on your machine's port 8001, serving the fixtures.db file in your current directory. Now visit http://127.0.0.1:8001/ to access Datasette. (You can download a copy of fixtures.db from https://latest.datasette.io/fixtures.db ) To upgrade to the most recent release of Datasette, run the following: docker pull datasetteproject/datasette",56, 95,Loading SpatiaLite,"The datasetteproject/datasette image includes a recent version of the SpatiaLite extension for SQLite. To load and enable that module, use the following command: docker run -p 8001:8001 -v `pwd`:/mnt \ datasetteproject/datasette \ datasette -p 8001 -h 0.0.0.0 /mnt/fixtures.db \ --load-extension=spatialite You can confirm that SpatiaLite is successfully loaded by visiting http://127.0.0.1:8001/-/versions",56, 96,Installing plugins,"If you want to install plugins into your local Datasette Docker image you can do so using the following recipe. This will install the plugins and then save a brand new local image called datasette-with-plugins : docker run datasetteproject/datasette \ pip install datasette-vega docker commit $(docker ps -lq) datasette-with-plugins You can now run the new custom image like so: docker run -p 8001:8001 -v `pwd`:/mnt \ datasette-with-plugins \ datasette -p 8001 -h 0.0.0.0 /mnt/fixtures.db You can confirm that the plugins are installed by visiting http://127.0.0.1:8001/-/plugins Some plugins such as datasette-ripgrep may need additional system packages. You can install these by running apt-get install inside the container: docker run datasette-057a0 bash -c ' apt-get update && apt-get install ripgrep && pip install datasette-ripgrep' docker commit $(docker ps -lq) datasette-with-ripgrep",56, 97,A note about extensions,"SQLite supports extensions, such as SpatiaLite for geospatial operations. These can be loaded using the --load-extension argument, like so: datasette --load-extension=/usr/local/lib/mod_spatialite.dylib Some Python installations do not include support for SQLite extensions. If this is the case you will see the following error when you attempt to load an extension: Your Python installation does not have the ability to load SQLite extensions. In some cases you may see the following error message instead: AttributeError: 'sqlite3.Connection' object has no attribute 'enable_load_extension' On macOS the easiest fix for this is to install Datasette using Homebrew: brew install datasette Use which datasette to confirm that datasette will run that version. The output should look something like this: /usr/local/opt/datasette/bin/datasette If you get a different location here such as /Library/Frameworks/Python.framework/Versions/3.10/bin/datasette you can run the following command to cause datasette to execute the Homebrew version instead: alias datasette=$(echo $(brew --prefix datasette)/bin/datasette) You can undo this operation using: unalias datasette If you need to run SQLite with extension support for other Python code, you can do so by install Python itself using Homebrew: brew install python Then executing Python using: /usr/local/opt/python@3/libexec/bin/python A more convenient way to work with this version of Python may be to use it to create a virtual environment: /usr/local/opt/python@3/libexec/bin/python -m venv datasette-venv Then activate it like this: source datasette-venv/bin/activate Now running python and pip will work against a version of Python 3 that includes support for SQLite extensions: pip install datasette which datasette datasette --version",56, 98,Running SQL queries,"Datasette treats SQLite database files as read-only and immutable. This means it is not possible to execute INSERT or UPDATE statements using Datasette, which allows us to expose SELECT statements to the outside world without needing to worry about SQL injection attacks. The easiest way to execute custom SQL against Datasette is through the web UI. The database index page includes a SQL editor that lets you run any SELECT query you like. You can also construct queries using the filter interface on the tables page, then click ""View and edit SQL"" to open that query in the custom SQL editor. Note that this interface is only available if the execute-sql permission is allowed. See Controlling the ability to execute arbitrary SQL . Any Datasette SQL query is reflected in the URL of the page, allowing you to bookmark them, share them with others and navigate through previous queries using your browser back button. You can also retrieve the results of any query as JSON by adding .json to the base URL.",56, 99,Named parameters,"Datasette has special support for SQLite named parameters. Consider a SQL query like this: select * from Street_Tree_List where ""PermitNotes"" like :notes and ""qSpecies"" = :species If you execute this query using the custom query editor, Datasette will extract the two named parameters and use them to construct form fields for you to provide values. You can also provide values for these fields by constructing a URL: /mydatabase?sql=select...&species=44 SQLite string escaping rules will be applied to values passed using named parameters - they will be wrapped in quotes and their content will be correctly escaped. Values from named parameters are treated as SQLite strings. If you need to perform numeric comparisons on them you should cast them to an integer or float first using cast(:name as integer) or cast(:name as real) , for example: select * from Street_Tree_List where latitude > cast(:min_latitude as real) and latitude < cast(:max_latitude as real) Datasette disallows custom SQL queries containing the string PRAGMA (with a small number of exceptions ) as SQLite pragma statements can be used to change database settings at runtime. If you need to include the string ""pragma"" in a query you can do so safely using a named parameter.",56, 100,Views,"If you want to bundle some pre-written SQL queries with your Datasette-hosted database you can do so in two ways. The first is to include SQL views in your database - Datasette will then list those views on your database index page. The quickest way to create views is with the SQLite command-line interface: sqlite3 sf-trees.db SQLite version 3.19.3 2017-06-27 16:48:08 Enter "".help"" for usage hints. sqlite> CREATE VIEW demo_view AS select qSpecies from Street_Tree_List; You can also use the sqlite-utils tool to create a view : sqlite-utils create-view sf-trees.db demo_view ""select qSpecies from Street_Tree_List""",56, 101,Canned queries,"As an alternative to adding views to your database, you can define canned queries inside your datasette.yaml file. Here's an example: [[[cog from metadata_doc import config_example, config_example config_example(cog, { ""databases"": { ""sf-trees"": { ""queries"": { ""just_species"": { ""sql"": ""select qSpecies from Street_Tree_List"" } } } } }) ]]] [[[end]]] Then run Datasette like this: datasette sf-trees.db -m metadata.json Each canned query will be listed on the database index page, and will also get its own URL at: /database-name/canned-query-name For the above example, that URL would be: /sf-trees/just_species You can optionally include ""title"" and ""description"" keys to show a title and description on the canned query page. As with regular table metadata you can alternatively specify ""description_html"" to have your description rendered as HTML (rather than having HTML special characters escaped).",56,