Setting the file. One moment.
Subchapter 63.24
references/mysql-migrations/ddl-column-changes.mdMarkdown1 KBView on GitHub
Part of MySQL to DSQL DDL Migration. See Common Verify & Swap Pattern for the shared migration end-pattern.
MySQL syntax:
ALTER TABLE table_name ALTER COLUMN column_name datatype;
-- or MySQL-specific:
ALTER TABLE table_name MODIFY COLUMN column_name new_datatype;
ALTER TABLE table_name CHANGE COLUMN old_name new_name new_datatype;DSQL: MUST use Table Recreation Pattern — see column-operations.md ALTER COLUMN TYPE for the full step-by-step pattern including pre-migration validation and data type compatibility matrix.
MySQL syntax:
ALTER TABLE table_name DROP COLUMN column_name;DSQL: MUST use Table Recreation Pattern — see column-operations.md DROP COLUMN for the full step-by-step pattern.
For tables > 3,000 rows, use Batched Migration Pattern.