Question

I need to add a new column to a MS SQL 2005 database with an initial value. However, I do NOT want to automatically create a default constraint on this column. At the point in time that I add the column the default/initial value is correct, but this can change over time. So, future access to the table MUST specify a value instead of accepting a default.

The best I could come up with is:

ALTER TABLE tbl ADD col INTEGER NULL
UPDATE tbl SET col = 1
ALTER TABLE tbl ALTER COLUMN col INTEGER NOT NULL

This seems a bit inefficient for largish tables (100,000 to 1,000,000 records).

I have experimented with adding the column with a default and then deleting the default constraint. However, I don’t know what the name of the default constraint is and would rather not access sysobjects and put in database specific knowledge.

Please, there must be a better way.

Answer 1

I’d ALTER TABLE tbl ADD col INTEGER CONSTRAINT tempname DEFAULT 1 first,, and drop the explicitly named constraint after (presumably within a transaction).