## 37.17. `constraint_column_usage`

The view `constraint_column_usage` identifies all columns in the current database that are used by some constraint. Only those columns are shown that are contained in a table owned by a currently enabled role. For a check constraint, this view identifies the columns that are used in the check expression. For a foreign key constraint, this view identifies the columns that the foreign key references. For a unique or primary key constraint, this view identifies the constrained columns.

Table 37.15. `constraint_column_usage` Columns

Name | Data Type | Description
--- | --- | ---
`table_catalog` | `sql_identifier` | Name of the database that contains the table that contains the column that is used by some constraint (always the current database)
`table_schema` | `sql_identifier` | Name of the schema that contains the table that contains the column that is used by some constraint
`table_name` | `sql_identifier` | Name of the table that contains the column that is used by some constraint
`column_name` | `sql_identifier` | Name of the column that is used by some constraint
`constraint_catalog` | `sql_identifier` | Name of the database that contains the constraint (always the current database)
`constraint_schema` | `sql_identifier` | Name of the schema that contains the constraint
`constraint_name` | `sql_identifier` | Name of the constraint