Identifying Foreign Key Constraints in MySQL
In MySQL, it is often necessary to retrieve a comprehensive view of foreign key constraints associated with a specific table or column. This information is crucial for understanding database relationships and ensuring data integrity.
Foreign Keys to a Table
To obtain a list of all foreign key constraints that point to a particular table, the following query can be used:
SELECT TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_SCHEMA = (SELECT DATABASE()) AND REFERENCED_TABLE_NAME = '<table>' \G
Foreign Keys to a Column
Similarly, to identify foreign key constraints that reference a specific column within a table, the query can be modified:
SELECT TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_SCHEMA = (SELECT DATABASE()) AND REFERENCED_TABLE_NAME = '<table>' AND REFERENCED_COLUMN_NAME = '<column>' \G
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