db.view_exists() method, needed by #1896

datasette/database.py

@@ -338,6 +338,12 @@ class Database:
         )
         return bool(results.rows)
 
+    async def view_exists(self, table):
+        results = await self.execute(
+            "select 1 from sqlite_master where type='view' and name=?", params=(table,)
+        )
+        return bool(results.rows)
+
     async def table_names(self):
         results = await self.execute(
             "select name from sqlite_master where type='table'"

docs/internals.rst

@@ -909,6 +909,9 @@ The ``Database`` class also provides properties and methods for introspecting th
 ``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.
 

tests/test_internals_database.py

@@ -78,6 +78,19 @@ async def test_table_exists(db, tables, exists):
         assert exists == actual
 
 
+@pytest.mark.parametrize(
+    "view,expected",
+    (
+        ("not_a_view", False),
+        ("paginated_view", True),
+    ),
+)
+@pytest.mark.asyncio
+async def test_view_exists(db, view, expected):
+    actual = await db.view_exists(view)
+    assert actual == expected
+
+
 @pytest.mark.parametrize(
     "table,expected",
     (