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sqlite-utils 4.2 adds lots of improvements to the table.transform() feature, which supports complex alter table operations by creating a fresh table, copying across the data, and then dropping and replacing the old one.

The release announcement highlights table.transform() as the main focus: it now supports complex ALTER TABLE operations by rebuilding a fresh table, copying data, then dropping and replacing the old one. ✦ AI generated

Simon Willison · Simon Willison's Weblog · 2026-08-13 · original ↗

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Lots of improvements in this one relating to the table.transform() feature, which adds support for complex alter table operations by creating a fresh table, copying across the data and then dropping and replacing the old one.

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✳ sqlite-utils

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There is no way to ALTER an existing SQLite table to make it strict; you have to copy the data out of the non-strict table into a new strict one.Evan Hahn · Simon Willison's Weblog · conf 60%

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extends → In sqlite-utils 4.2, transform() preserves a much larger array of edge-case schema definitions, including check constraints, unique constraints, and even comments describing the columns.Simon Willison · Simon Willison's Weblog explains mechanism → table.transform()/table.transform_sql() and the sqlite-utils transform CLI command now accept strict=True/False or --strict/--no-strict to change a table's SQLite strict mode, since transform already copies data into a new table and can therefore switch strictness in either direction.Simon Willison · Simon Willison's Weblog explains mechanism → table.transform() implements the SQLite-documentation-recommended pattern for altering tables beyond what ALTER TABLE supports: create a new temp table with the new schema, copy the data across, then drop the old table and rename the new one into place.Simon Willison · Simon Willison's Weblog