id,page,ref,title,content,breadcrumbs,references
changelog:writable-canned-queries,changelog,writable-canned-queries,Writable canned queries,"Datasette's  Canned queries  feature lets you define SQL queries in  metadata.json  which can then be executed by users visiting a specific URL.  https://latest.datasette.io/fixtures/neighborhood_search  for example. 
                 Canned queries were previously restricted to  SELECT , but Datasette 0.44 introduces the ability for canned queries to execute  INSERT  or  UPDATE  queries as well, using the new  ""write"": true  property ( #800 ): 
                 {
    ""databases"": {
        ""dogs"": {
            ""queries"": {
                ""add_name"": {
                    ""sql"": ""INSERT INTO names (name) VALUES (:name)"",
                    ""write"": true
                }
            }
        }
    }
} 
                 See  Writable canned queries  for more details.","[""Changelog"", ""0.44 (2020-06-11)""]","[{""href"": ""https://latest.datasette.io/fixtures/neighborhood_search"", ""label"": ""https://latest.datasette.io/fixtures/neighborhood_search""}, {""href"": ""https://github.com/simonw/datasette/issues/800"", ""label"": ""#800""}]"
sql_queries:canned-queries-writable,sql_queries,canned-queries-writable,Writable canned queries,"Canned queries by default are read-only. You can use the  ""write"": true  key to indicate that a canned query can write to the database. 
                 See  Access to specific canned queries  for details on how to add permission checks to canned queries, using the  ""allow""  key. 
                 [[[cog
config_example(cog, {
    ""databases"": {
        ""mydatabase"": {
            ""queries"": {
                ""add_name"": {
                    ""sql"": ""INSERT INTO names (name) VALUES (:name)"",
                    ""write"": True
                }
            }
        }
    }
}) 
                 ]]] 
                 [[[end]]] 
                 This configuration will create a page at  /mydatabase/add_name  displaying a form with a  name  field. Submitting that form will execute the configured  INSERT  query. 
                 You can customize how Datasette represents success and errors using the following optional properties: 
                 
                     
                         on_success_message  - the message shown when a query is successful 
                     
                     
                         on_success_message_sql  - alternative to  on_success_message : a SQL query that should be executed to generate the message 
                     
                     
                         on_success_redirect  - the path or URL the user is redirected to on success 
                     
                     
                         on_error_message  - the message shown when a query throws an error 
                     
                     
                         on_error_redirect  - the path or URL the user is redirected to on error 
                     
                 
                 For example: 
                 [[[cog
config_example(cog, {
    ""databases"": {
        ""mydatabase"": {
            ""queries"": {
                ""add_name"": {
                    ""sql"": ""INSERT INTO names (name) VALUES (:name)"",
                    ""params"": [""name""],
                    ""write"": True,
                    ""on_success_message_sql"": ""select 'Name inserted: ' || :name"",
                    ""on_success_redirect"": ""/mydatabase/names"",
                    ""on_error_message"": ""Name insert failed"",
                    ""on_error_redirect"": ""/mydatabase"",
                }
            }
        }
    }
}) 
                 ]]] 
                 [[[end]]] 
                 You can use  ""params""  to explicitly list the named parameters that should be displayed as form fields - otherwise they will be automatically detected.  ""params""  is not necessary in the above example, since without it  ""name""  would be automatically detected from the query. 
                 You can pre-populate form fields when the page first loads using a query string, e.g.  /mydatabase/add_name?name=Prepopulated . The user will have to submit the form to execute the query. 
                 If you specify a query in  ""on_success_message_sql"" , that query will be executed after the main query. The first column of the first row return by that query will be displayed as a success message. Named parameters from the main query will be made available to the success message query as well.","[""Running SQL queries"", ""Canned queries""]",[]