28.3.41 The INFORMATION_SCHEMA TABLE_CONSTRAINTS Table

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MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4

28.3.41 The INFORMATION_SCHEMA TABLE_CONSTRAINTS Table

The TABLE_CONSTRAINTS table describes which tables have constraints.

The TABLE_CONSTRAINTS table has these columns:

  • CONSTRAINT_CATALOG

The name of the catalog to which the constraint belongs. This value is always def. - CONSTRAINT_SCHEMA

The name of the schema (database) to which the constraint belongs. - CONSTRAINT_NAME

The name of the constraint. - TABLE_SCHEMA

The name of the schema (database) to which the table belongs. - TABLE_NAME

The name of the table. - CONSTRAINT_TYPE

The type of constraint. The value can be UNIQUE, PRIMARY KEY, FOREIGN KEY or CHECK. This is a CHAR (not ENUM) column.

The UNIQUE and PRIMARY KEY information is about the same as what you get from the Key_name column in the output from SHOW INDEX when the Non_unique column is 0. - ENFORCED

For CHECK constraints, the value is YES or NO to indicate whether the constraint is enforced. For other constraints, the value is always YES.