Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Implementing Constraints

Implementing Constraints

From: Victor <lch_1_at_hotmail.com>
Date: Sun, 1 Jul 2001 14:38:36 +0800
Message-ID: <9hmg7e$7qh41@imsp212.netvigator.com>

Dear all,

In the oracle book, i found the following syntax in defining the constraint:

column dataytpe {CONSTRAINT constraint]
in_line_constraint
[defer_spec]
in_line_constraint :==
{[NOT] NULL
| PRIMARY KEY
.
.
.

defer_spec :==
[NOT DEFERRABLE | DEFERRABLE [INITIALLY {IMMEDIATE | DEFERRED}]
.
.

I don't understand why the DEFERABLE syntax can be used with the IMMEDIATE syntax. From the book, the use of IMMEDIATE syntax indicate that the default is to check this constraint at the end of every DML statement. But DEFFERABLE means check when COMMIT.
It makes me confuse

THX Received on Sun Jul 01 2001 - 01:38:36 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US