Thread

1. Referential Integrity

   Mike Lemler <coronach@datacruz.com> — 1998-05-13T20:28:42Z

   I haven't been able to find documentation on how to implement referential
   integrity between tables with postgres via sql.  Could someone please post
   an example.  Thanks.
   
   Michael.
   
   
   

2. Re: Referential Integrity

   jose' soares <sferac@bo.nettuno.it> — 1998-05-14T10:57:09Z

   On Wed, 13 May 1998, Mike Lemler wrote:
   
   > I haven't been able to find documentation on how to implement referential
   > integrity between tables with postgres via sql.  Could someone please post
   > an example.  Thanks.
   > 
   > Michael.
   > 
      Table Constraint definition:
   
         [ CONSTRAINT name ] 
           { PRIMARY KEY constraint | 
             UNIQUE constraint | 
             CHECK constraint }
   
      Column Constraint definition: 
   
         [ CONSTRAINT name ] 
           { NOT NULL constraint |
             PRIMARY KEY constraint | 
             UNIQUE constraint | 
             CHECK constraint }  
   
   examples:
   
      --defines a CHECK column constraint:
      --
      CREATE TABLE distributors (
           did      DECIMAL(3) CHECK (did > 100),
           name     VARCHAR(40)
           );
   
      --defines a CHECK table constraint:
      --
      CREATE TABLE distributors (
           did      DECIMAL(3),
           name     VARCHAR(40)
           CONSTRAINT con1 CHECK (did > 100 AND name > '')
           );
   
   PS: FOREIGN KEY is not implemented yet you can use TRIGGERS instead
       take a look at ...contrib/refint*
                                                        Jose'