Support for Create Table As #12860

gjarzab · 2025-09-12T20:00:54Z

This PR adds support for the Create Table AS construct, along with a new .into() constructor on Select.

Description

Introduces CreateTableAs element which can then be used to render CREATE TABLE ... AS ... statements.
A CreateTableAs can either be constructed directly or from a Select / Selectable by using the new .into constructor method added to the Select class.

Compilation with the default dialect does not render any flags like TEMPORARY or IF NOT EXISTS. Support for these can be added in the dialect specific compilers. Compilation of CreateTableAs for SQLite supports TEMPORARY and IF NOT EXISTS.

#Basic CreateTableAs usage
CreateTableAs(select(users.c.id, users.c.name).select_from(users), "active_users")

# Using .into() on a Select
select(users.c.id).where(users.c.status == "inactive").into("inactive_users")

# With schema and IF NOT EXISTS
select(users.c.id).into("archived", schema="analytics", if_not_exists=True)

# Temporary table
select(users.c.id, users.c.name).into("temp_snapshot", temporary=True)

Fixes issue : #4950

Checklist

This pull request is:

A documentation / typographical / small typing error fix
- Good to go, no issue or tests are needed
A short code fix
- please include the issue number, and create an issue if none exists, which
  must include a complete example of the issue. one line code fixes without an
  issue and demonstration will not be accepted.
- Please include: Fixes: #<issue number> in the commit message
- please include tests. one line code fixes without tests will not be accepted.
A new feature implementation
- please include the issue number, and create an issue if none exists, which must
  include a complete example of how the feature would look.
- Please include: Fixes: #<issue number> in the commit message
- please include tests.

sqla-tester

OK, this is sqla-tester setting up my work on behalf of zzzeek to try to get revision a18f053 of this pull request into gerrit so we can run tests and reviews and stuff

sqla-tester · 2025-09-15T22:10:59Z

New Gerrit review created for change a18f053: https://gerrit.sqlalchemy.org/c/sqlalchemy/sqlalchemy/+/6115

zzzeek · 2025-09-15T22:11:08Z

I'm very swamped in PRs, sorry this is moving slowly

zzzeek · 2025-09-19T20:41:48Z

are you able to run tox -e pep484 and take a look at the typing errors ?

zzzeek

looks good so far. lots of tests. I want to use fixtures as much as we can for these tests to limit the verbosity. We have a decorator @testing.fixture() that is basically a synonym for pytest fixtures: https://docs.pytest.org/en/6.2.x/fixture.html

a lot of the code in this sqlite suite might be pretty old but let's try to use the more recent patterns for these new tests. (at some point I have to break test_sqlite into a package also).

zzzeek · 2025-09-19T20:44:34Z

lib/sqlalchemy/sql/selectable.py

+        temporary: bool = False,
+        if_not_exists: bool = False,
+    ) -> "CreateTableAs":
+        from .ddl import CreateTableAs


if this ddl import can't be at the top., we have a system used for in-method imports that's threadsafe

@util.preload_module("sqlalchemy.ddl") def my_method(self, ...): ddl = util.preloaded.ddl return ddl.CreateTableAs(...)

zzzeek · 2025-09-19T20:48:24Z

test/dialect/test_sqlite.py

+        self.src_def = "CREATE TABLE src (id INTEGER PRIMARY KEY, name TEXT)"
+        self.seed_def = "INSERT INTO src (name) VALUES ('a'), ('b')"
+
+    def teardown_test(self):


note in the exec_sql() function at the top of the file it has a comment "convert all tests to not use this" :) so for these raw SQL fixtures, I'd do it like this:

def teardown_test(self): with testing.db.begin() as conn: conn.exec_driver_sql(...) conn.exec_driver_sql(...) conn.exec_driver_sql(...) ...

but also I think these drops can all be turned into fixtures, see my other comments

zzzeek · 2025-09-19T20:50:31Z

test/dialect/test_sqlite.py

+    __only_on__ = "sqlite"
+    __backend__ = True
+
+    @staticmethod


use a fixture for this:

@testing.fixture def source_table(self): return table("src", column("id"), column("name"))

then in a test

def test_thing(self, source_table, connection): stmt = select(source_table).where(....)

zzzeek · 2025-09-19T20:51:07Z

test/dialect/test_sqlite.py

+        return table("src", column("id"), column("name"))
+
+    @staticmethod
+    def _two_sources():


use a fixture here also...

zzzeek · 2025-09-19T20:53:15Z

test/dialect/test_sqlite.py

+
+    def setup_test(self):
+        # define a physical src table and seed a couple rows
+        self.src_def = "CREATE TABLE src (id INTEGER PRIMARY KEY, name TEXT)"


these can be fixtures

@testing.fixture def src_def(self, connection): connection.exec_driver_sql("CREATE TABLE ....") yield connection.exec_driver_sql("DROP TABLE ....") @testing.fixture def seeded_src_def(self, connection, src_def): connection.exec_driver_sql("INSERT INTO src (name) VALUES ('a'), ('b')")

then in a test

def test_a_thing(self, seeded_src_def): # the table is there, and aill also drop when finished

Thank you for the feedback. I updated the SQLite and default dialect tests to use fixtures. A yield fixture also works nicely for cleaning up of tables created via CreateTableAs within the SQLite backend tests.

add CreateTableAs for default dialect and SQLite. add Select.into constructor for CreateTableAs.

gjarzab · 2025-09-23T04:41:30Z

are you able to run tox -e pep484 and take a look at the typing errors ?

This was due to an instance of TableClause being assigned to the target attribute defined in ExecutableDDLElement which is of type Union[SchemaItem, str,None].

Now CreateTableAs assigns a TableClause instance to an attribute called table and leaves the target attribute as None. As far as I can tell this shouldn't cause any issues.

zzzeek requested a review from sqla-tester September 15, 2025 22:10

sqla-tester reviewed Sep 15, 2025

View reviewed changes

zzzeek requested changes Sep 19, 2025

View reviewed changes

gjarzab added 2 commits September 22, 2025 15:10

ignore __pycache__ directory

56bc512

Fixes: sqlalchemy#4950

aa14126

add CreateTableAs for default dialect and SQLite. add Select.into constructor for CreateTableAs.

gjarzab force-pushed the feature/create-table-as branch from a18f053 to aa14126 Compare September 23, 2025 03:09

use fixture for CreateTableAs default dialect tests

7de8a10

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

Support for Create Table As #12860

Support for Create Table As #12860

Uh oh!

gjarzab commented Sep 12, 2025

Uh oh!

sqla-tester left a comment

Uh oh!

sqla-tester commented Sep 15, 2025

Uh oh!

zzzeek commented Sep 15, 2025

Uh oh!

zzzeek commented Sep 19, 2025

Uh oh!

zzzeek left a comment

Uh oh!

zzzeek Sep 19, 2025

Uh oh!

zzzeek Sep 19, 2025

Uh oh!

zzzeek Sep 19, 2025

Uh oh!

zzzeek Sep 19, 2025

Uh oh!

zzzeek Sep 19, 2025

Uh oh!

gjarzab Sep 23, 2025

Uh oh!

gjarzab commented Sep 23, 2025

Uh oh!

Uh oh!

Uh oh!

Support for Create Table As #12860

Are you sure you want to change the base?

Support for Create Table As #12860

Uh oh!

Conversation

gjarzab commented Sep 12, 2025

Description

Checklist

Uh oh!

sqla-tester left a comment

Choose a reason for hiding this comment

Uh oh!

sqla-tester commented Sep 15, 2025

Uh oh!

zzzeek commented Sep 15, 2025

Uh oh!

zzzeek commented Sep 19, 2025

Uh oh!

zzzeek left a comment

Choose a reason for hiding this comment

Uh oh!

zzzeek Sep 19, 2025

Choose a reason for hiding this comment

Uh oh!

zzzeek Sep 19, 2025

Choose a reason for hiding this comment

Uh oh!

zzzeek Sep 19, 2025

Choose a reason for hiding this comment

Uh oh!

zzzeek Sep 19, 2025

Choose a reason for hiding this comment

Uh oh!

zzzeek Sep 19, 2025

Choose a reason for hiding this comment

Uh oh!

gjarzab Sep 23, 2025

Choose a reason for hiding this comment

Uh oh!

gjarzab commented Sep 23, 2025

Uh oh!

Uh oh!