# Page Not Found

The URL `sql/features/constraints/xpand/foreign-key` does not exist.

You might be looking for one of these pages:
- [Foreign Keys](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/optimization-and-indexes/foreign-keys.md)
- [FOREIGN KEY Constraints](https://mariadb.com/docs/server/architecture/server-constraints/foreign-key-constraints.md)
- [Replication and Foreign Keys](https://mariadb.com/docs/server/ha-and-performance/standard-replication/replication-and-foreign-keys.md)
- [FOR UPDATE](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/selecting-data/for-update.md)
- [COERCIBILITY](https://mariadb.com/docs/server/reference/sql-functions/secondary-functions/information-functions/coercibility.md)

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