diff --git a/datasette/utils/__init__.py b/datasette/utils/__init__.py index aec5a55b..44641a87 100644 --- a/datasette/utils/__init__.py +++ b/datasette/utils/__init__.py @@ -1076,3 +1076,15 @@ class PrefixedUrlString(str): class StartupError(Exception): pass + + +_re_named_parameter = re.compile(":([a-zA-Z0-9_]+)") + +async def derive_named_parameters(db, sql): + explain = 'explain {}'.format(sql.strip().rstrip(";")) + possible_params = _re_named_parameter.findall(sql) + try: + results = await db.execute(explain, {p: None for p in possible_params}) + return [row["p4"].lstrip(":") for row in results if row["opcode"] == "Variable"] + except sqlite3.DatabaseError: + return [] diff --git a/datasette/views/base.py b/datasette/views/base.py index cd584899..1cea1386 100644 --- a/datasette/views/base.py +++ b/datasette/views/base.py @@ -159,7 +159,6 @@ class BaseView: class DataView(BaseView): name = "" - re_named_parameter = re.compile(":([a-zA-Z0-9_]+)") async def options(self, request, *args, **kwargs): r = Response.text("ok") diff --git a/datasette/views/database.py b/datasette/views/database.py index 29600659..7c36034c 100644 --- a/datasette/views/database.py +++ b/datasette/views/database.py @@ -10,6 +10,7 @@ import markupsafe from datasette.utils import ( await_me_maybe, check_visibility, + derive_named_parameters, to_css_class, validate_sql_select, is_url, @@ -223,7 +224,9 @@ class QueryView(DataView): await self.check_permission(request, "execute-sql", database) # Extract any :named parameters - named_parameters = named_parameters or self.re_named_parameter.findall(sql) + named_parameters = named_parameters or await derive_named_parameters( + self.ds.get_database(database), sql + ) named_parameter_values = { named_parameter: params.get(named_parameter) or "" for named_parameter in named_parameters diff --git a/tests/test_utils.py b/tests/test_utils.py index 97b70ee5..e04efb4b 100644 --- a/tests/test_utils.py +++ b/tests/test_utils.py @@ -626,3 +626,18 @@ def test_parse_metadata(content, expected): utils.parse_metadata(content) else: assert utils.parse_metadata(content) == expected + + +@pytest.mark.asyncio +@pytest.mark.parametrize("sql,expected", ( + ("select 1", []), + ("select 1 + :one", ["one"]), + ("select 1 + :one + :two", ["one", "two"]), + ("select 'bob' || '0:00' || :cat", ["cat"]), + ("select this is invalid", []), +)) +async def test_derive_named_parameters(sql, expected): + ds = Datasette([], memory=True) + db = ds.get_database("_memory") + params = await utils.derive_named_parameters(db, sql) + assert params == expected