| PostgreSQL 9.4.26 Documentation | |||
|---|---|---|---|
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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 34-15. 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 |