catalog_views table, closes #2495

Refs https://github.com/datasette/datasette-queries/issues/1#issuecomment-3074491003

datasette/utils/internal_db.py

@@ -19,6 +19,14 @@ async def init_internal_db(db):
         PRIMARY KEY (database_name, table_name),
         FOREIGN KEY (database_name) REFERENCES catalog_databases(database_name)
     );
+    CREATE TABLE IF NOT EXISTS catalog_views (
+        database_name TEXT,
+        view_name TEXT,
+        rootpage INTEGER,
+        sql TEXT,
+        PRIMARY KEY (database_name, view_name),
+        FOREIGN KEY (database_name) REFERENCES catalog_databases(database_name)
+    );
     CREATE TABLE IF NOT EXISTS catalog_columns (
         database_name TEXT,
         table_name TEXT,
@@ -111,6 +119,9 @@ async def populate_schema_tables(internal_db, db):
         conn.execute(
             "DELETE FROM catalog_tables WHERE database_name = ?", [database_name]
         )
+        conn.execute(
+            "DELETE FROM catalog_views WHERE database_name = ?", [database_name]
+        )
         conn.execute(
             "DELETE FROM catalog_columns WHERE database_name = ?", [database_name]
         )
@@ -125,13 +136,21 @@ async def populate_schema_tables(internal_db, db):
     await internal_db.execute_write_fn(delete_everything)
 
     tables = (await db.execute("select * from sqlite_master WHERE type = 'table'")).rows
+    views = (await db.execute("select * from sqlite_master WHERE type = 'view'")).rows
 
     def collect_info(conn):
         tables_to_insert = []
+        views_to_insert = []
         columns_to_insert = []
         foreign_keys_to_insert = []
         indexes_to_insert = []
 
+        for view in views:
+            view_name = view["name"]
+            views_to_insert.append(
+                (database_name, view_name, view["rootpage"], view["sql"])
+            )
+
         for table in tables:
             table_name = table["name"]
             tables_to_insert.append(
@@ -165,6 +184,7 @@ async def populate_schema_tables(internal_db, db):
             )
         return (
             tables_to_insert,
+            views_to_insert,
             columns_to_insert,
             foreign_keys_to_insert,
             indexes_to_insert,
@@ -172,6 +192,7 @@ async def populate_schema_tables(internal_db, db):
 
     (
         tables_to_insert,
+        views_to_insert,
         columns_to_insert,
         foreign_keys_to_insert,
         indexes_to_insert,
@@ -184,6 +205,13 @@ async def populate_schema_tables(internal_db, db):
     """,
         tables_to_insert,
     )
+    await internal_db.execute_write_many(
+        """
+        INSERT INTO catalog_views (database_name, view_name, rootpage, sql)
+        values (?, ?, ?, ?)
+    """,
+        views_to_insert,
+    )
     await internal_db.execute_write_many(
         """
         INSERT INTO catalog_columns (

docs/internals.rst

@@ -1378,7 +1378,7 @@ 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.
+Datasette maintains tables called ``catalog_databases``, ``catalog_tables``, ``catalog_views``, ``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 :ref:`get_*_metadata() and set_*_metadata() methods <datasette_get_set_metadata>`.
 
@@ -1421,6 +1421,14 @@ The internal database schema is as follows:
         PRIMARY KEY (database_name, table_name),
         FOREIGN KEY (database_name) REFERENCES catalog_databases(database_name)
     );
+    CREATE TABLE catalog_views (
+        database_name TEXT,
+        view_name TEXT,
+        rootpage INTEGER,
+        sql TEXT,
+        PRIMARY KEY (database_name, view_name),
+        FOREIGN KEY (database_name) REFERENCES catalog_databases(database_name)
+    );
     CREATE TABLE catalog_columns (
         database_name TEXT,
         table_name TEXT,

tests/test_internal_db.py

@@ -25,6 +25,15 @@ async def test_internal_tables(ds_client):
     assert set(table.keys()) == {"rootpage", "table_name", "database_name", "sql"}
 
 
+@pytest.mark.asyncio
+async def test_internal_views(ds_client):
+    internal_db = await ensure_internal(ds_client)
+    views = await internal_db.execute("select * from catalog_views")
+    assert len(views) >= 4
+    view = views.rows[0]
+    assert set(view.keys()) == {"rootpage", "view_name", "database_name", "sql"}
+
+
 @pytest.mark.asyncio
 async def test_internal_indexes(ds_client):
     internal_db = await ensure_internal(ds_client)