RE: default constraint updating existing rows

From: Hostetter, Jay M <>
Date: Tue, 16 Dec 2008 13:43:45 -0500
Message-ID: <>

Try splitting the "alter table" into two different statements.

Alter table test add (b int);

Alter table test modify (b int default 3);


-----Original Message-----

[] On Behalf Of Harvinder Singh Sent: Tuesday, December 16, 2008 1:22 PM To:
Subject: default constraint updating existing rows


We are adding a column with default constraint and we only want it to apply to new rows but it is updating existing rows even though column allows null. I am using the following test:

SQL> create table test (a int);

Table created.

SQL> insert into test values(1);

1 row created.

SQL> insert into test values(2);

1 row created.

SQL> alter table test add b int default 3;

Table altered.

SQL> select * from test;

         A B
---------- ----------

         1          3
         2          3

SQL> desc test
 Name                                      Null?    Type
 ----------------------------------------- -------- --------------

 A                                                  NUMBER(38)
 B                                                  NUMBER(38)

Is there any way to add new column with default constraint without updating existing rows?


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-- Received on Tue Dec 16 2008 - 12:43:45 CST

Original text of this message