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 32-11. 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 |