35.18. 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 not-null constraint, this view identifies the
   column that the constraint is defined on. 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 35.16. 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