Fix offline --sql mode incorrectly emitting DROP TABLE for alembic_version#1827
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Suchethan021 wants to merge 1 commit into
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Fix offline --sql mode incorrectly emitting DROP TABLE for alembic_version#1827Suchethan021 wants to merge 1 commit into
Suchethan021 wants to merge 1 commit into
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…rsion Running 'stamp base --sql' or 'downgrade <rev>:base --sql' would emit a DROP TABLE alembic_version statement. Online mode never drops the version table (it only deletes rows), so this was an inconsistency introduced in the very early commits of the project. Remove the block from MigrationContext.run_migrations() that emitted the table drop exclusively in --sql mode when all heads were removed. Add an explanatory comment and an additional test covering 'stamp base --sql'. Fixes: sqlalchemy#1822
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Summary
Running
alembic stamp base --sqloralembic downgrade <rev>:base --sqlincorrectly emits aDROP TABLE alembic_versionstatement. Online mode never drops the version table — it only deletes rows from it — so this was an inconsistency introduced in a very early commit (2da7f004) before the 0.1 release.The maintainer confirmed this is a bug:
Changes
alembic/runtime/migration.pyRemoved the block in
MigrationContext.run_migrations()that conditionally dropped the version table whenas_sql=Trueand no heads remained. Added an explanatory comment for future readers.tests/test_command.pytest_version_to_noneassertion to expectDROP TABLE alembic_versionis not present in--sqloutput.test_sql_stamp_to_base_no_dropto explicitly cover thestamp base --sqlpath.docs/build/unreleased/1822.rstAdded changelog entry following Alembic'''s per-file changelog convention.
Test results
(Python 3.13.3 / SQLite; DB-specific and
test_post_writeskipped as expected)Fixes #1822