Added alembic script to resize url and slug columns to 191 #1192
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nmveeresh
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crivetimihai,
kevalmahajan and
madhav165
as code owners
Signed-off-by: Veeresh K <[email protected]>
Signed-off-by: Veeresh K <[email protected]>
Signed-off-by: Veeresh K <[email protected]>
Signed-off-by: Veeresh K <[email protected]>
- Update db.py SQLAlchemy model to match migration (String(191)) - Add dialect-specific SQL handling in migration (SQLite, PostgreSQL, MySQL) - Use CHAR_LENGTH for character-based truncation (not byte-based LENGTH in MySQL) - Ensure truncation works correctly across all supported database backends
- SQLite doesn't support ALTER COLUMN TYPE directly - Use batch_alter_table for SQLite (creates temp table, copies data, renames) - Keep direct ALTER COLUMN for PostgreSQL and MySQL - Applies to both upgrade and downgrade operations - Fixes: sqlalchemy.exc.OperationalError with SQLite
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🧾 PR Summary: Resize
slugandurlColumns to 191 CharactersBackground
In the existing schema, the following columns had larger lengths:
slug→VARCHAR(255)url→VARCHAR(767)These lengths exceeded typical index length limits on some databases (especially MySQL with UTF8MB4 encoding), potentially causing compatibility or index creation issues.
Change Summary
This migration adjusts both columns to a consistent and safer maximum length of 191 characters.
Migration Details
Upgrade (
2f67b12600b4 → 878e287d2366):slug:VARCHAR(255)→VARCHAR(191)url:VARCHAR(767)→VARCHAR(191)Downgrade (
878e287d2366 → 2f67b12600b4):slug:VARCHAR(191)→VARCHAR(255)url:VARCHAR(191)→VARCHAR(767)Rationale
Verification