36.51. table_constraints
  The view
  
   table_constraints
  
  contains all
   constraints belonging to tables that the current user owns or has
   some privilege other than
  
   SELECT
  
  on.
 
   
    Table 36.49. 
    
     table_constraints
    
    Columns
   
  
| Name | Data Type | Description | 
|---|---|---|
| 
        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 | 
| 
        table_catalog
        | 
        sql_identifier
        | Name of the database that contains the table (always the current database) | 
| 
        table_schema
        | 
        sql_identifier
        | Name of the schema that contains the table | 
| 
        table_name
        | 
        sql_identifier
        | Name of the table | 
| 
        constraint_type
        | 
        character_data
        | Type of the constraint: 
        CHECK
       ,
        FOREIGN KEY
       ,
        PRIMARY KEY
       ,
       or
        UNIQUE
        | 
| 
        is_deferrable
        | 
        yes_or_no
        | 
        YES
       if the constraint is deferrable,
        NO
       if not | 
| 
        initially_deferred
        | 
        yes_or_no
        | 
        YES
       if the constraint is deferrable and initially deferred,
        NO
       if not | 
| 
        enforced
        | 
        yes_or_no
        | Applies to a feature not available in
       
        PostgreSQL
       
       (currently always 
        YES
       ) |