## 36.18. `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 36.16. `constraint_column_usage` Columns

Column 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