table_constraints

The table_constraints view describes which tables have constraints. This view is read-only. All users have the read permission on this view.

**Table 1** information_schema.table_constraints columns
Name	Type	Description
CONSTRAINT_CATALOG	varchar(512)	Name of the database to which the constraint belongs. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
CONSTRAINT_SCHEMA	varchar(64)	Name of the schema to which the constraint belongs. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
CONSTRAINT_NAME	varchar(64)	Name of the constraint. If the constraint is a primary key constraint, PRIMARY is displayed.
TABLE_SCHEMA	varchar(64)	Name of the schema to which the table belongs. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
TABLE_NAME	varchar(64)	Name of the table. When lower_case_table_names is set to 0, the value of this column is case-sensitive. When lower_case_table_names is set to 1, the value of this column is case-insensitive.
CONSTRAINT_TYPE	varchar(64)	Type of the constraint. The value is unique, primary key, foreign key, or check.