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12 rows where breadcrumbs contains "Database class" sorted by ref
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id | page | ref ▼ | title | content | breadcrumbs | references |
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internals:database-execute-write-fn | internals | database-execute-write-fn | 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. | ["Internals for plugins", "Database class"] | [] |
internals:database-execute-write-many | internals | database-execute-write-many | 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. | ["Internals for plugins", "Database class"] | [{"href": "https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.executemany", "label": "conn.executemany()"}] |
internals:database-execute-write-script | internals | database-execute-write-script | 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. | ["Internals for plugins", "Database class"] | [{"href": "https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.executescript", "label": "conn.executescript()"}] |
internals:database-hash | internals | database-hash | 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 . | ["Internals for plugins", "Database class"] | [] |
internals:database-results | internals | database-results | 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] . .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 wit… | ["Internals for plugins", "Database class"] | [{"href": "https://docs.python.org/3/library/sqlite3.html#row-objects", "label": "Row objects"}] |
internals:internals-database-introspection | internals | internals-database-introspection | 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 … | ["Internals for plugins", "Database class"] | [] |
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CREATE TABLE [sections] ( [id] TEXT PRIMARY KEY, [page] TEXT, [ref] TEXT, [title] TEXT, [content] TEXT, [breadcrumbs] TEXT, [references] TEXT );