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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2022-07-01 09:56:10 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2022-07-01 11:54:16 -0400 |
| commit | cabccf6d05aaf119414166b260f322c8661352ac (patch) | |
| tree | 4dcda5a50a295cb11fc8a8666d824b69d45e74f9 /alembic/operations | |
| parent | 852bea05b2665856cc5cc88652c0a66863747415 (diff) | |
| download | alembic-cabccf6d05aaf119414166b260f322c8661352ac.tar.gz | |
fail gracefully for batch_alter_table() called in --sql mode
Added an error raise for the condition where
:meth:`.Operations.batch_alter_table` is used in ``--sql`` mode, where the
operation requires table reflection, as is the case when running against
SQLite without giving it a fixed ``Table`` object. Previously the operation
would fail with an internal error. To get a "move and copy" batch
operation as a SQL script without connecting to a database,
a ``Table`` object should be passed to the
:paramref:`.Operations.batch_alter_table.copy_from` parameter so that
reflection may be skipped.
Change-Id: I2d040e7e5771eefabba1649d71ed451567c25283
Fixes: #1021
Diffstat (limited to 'alembic/operations')
| -rw-r--r-- | alembic/operations/batch.py | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/alembic/operations/batch.py b/alembic/operations/batch.py index 7c7de9f..71d2681 100644 --- a/alembic/operations/batch.py +++ b/alembic/operations/batch.py @@ -119,6 +119,21 @@ class BatchOperationsImpl: existing_table = self.copy_from reflected = False else: + if self.operations.migration_context.as_sql: + raise exc.CommandError( + f"This operation cannot proceed in --sql mode; " + f"batch mode with dialect " + f"{self.operations.migration_context.dialect.name} " # noqa: E501 + f"requires a live database connection with which " + f'to reflect the table "{self.table_name}". ' + f"To generate a batch SQL migration script using " + "table " + '"move and copy", a complete Table object ' + f'should be passed to the "copy_from" argument ' + "of the batch_alter_table() method so that table " + "reflection can be skipped." + ) + existing_table = Table( self.table_name, m1, |