Documentation Home
MySQL 8.3 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 40.7Mb
PDF (A4) - 40.8Mb
Man Pages (TGZ) - 293.3Kb
Man Pages (Zip) - 408.3Kb
Info (Gzip) - 4.0Mb
Info (Zip) - 4.0Mb
Excerpts from this Manual

MySQL 8.3 Reference Manual  /  ...  /  The INFORMATION_SCHEMA TABLE_CONSTRAINTS Table

28.3.42 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.