how to create 'view migration' script using alembic tool

Question

Does somebody know how to use create_view function to create a view using alembic upgrade function? for example, we have:

CREATE VIEW myview AS
SELECT column_name(s)
FROM table_name
 WHERE condition

Now we want to define a view in alembic upgrade function script to create 'myview'. How to realize that?

Thanks.

Answer 1

I know, the question is way too old and probably the possibility didn't exist at that time. However for all the ones coming to this question now: there exists a possibility now described in the cookbook.

It leverages the creation, deletion and replacement of objects like views and stored procedures by giving you additional operations like op.create_view, op.drop_view or op.replace_view(myview, replaces="3f2ab897a.myview"). The same is true for stored procedures and can be also extended for e.g. user defined functions.

A view is defined the following way:

myview = ReplaceableObject('myview',
    """
    SELECT * FROM mytable
    """
)

Of course all of this can also be done with simple op.execute statements, however in this case alembic takes care of the DROP VIEW, CREATE VIEW and ALTER VIEW commands.