>Hi everybody,
>
>This code
>
>

>IF NOT EXISTS
>(SELECT column_name
>FROM information_schema.columns
>WHERE table_name = N'AdultInfo' and column_name = N'MaritalStatus')
>
>   BEGIN
>	alter table AdultInfo add MaritalStatus char(1) null
>	ALTER TABLE [dbo].[AdultInfo]  WITH CHECK ADD  CONSTRAINT [CK_AdultInfo] CHECK  (([MaritalStatus] IS NULL OR ([MaritalStatus] IN ('W','S','D','M'))))
>  END
>

>
>produces an error on the second line (adding CHECK constraint). Perhaps because the field is not added immediatelly?
>
>If I execute the lines one by one it works. So, I guess I may need to add one more test for the existence of the field before the second ALTER TABLE.
>
>Do you see why I'm getting the error and how can I correct the problem?
>
>Thanks a lot in advance.

You get error because the transaction is not committed yet and the new field is not in the table. Try this:

IF NOT EXISTS(SELECT column_name
                                     FROM information_schema.columns
                                     WHERE table_name = N'AdultInfo' and column_name = N'MaritalStatus')
   BEGIN
        sp_executesql N'alter table AdultInfo add MaritalStatus char(1) null' -- Only to be in other batch
        ALTER TABLE [dbo].[AdultInfo]  WITH CHECK ADD  CONSTRAINT [CK_AdultInfo] CHECK  (([MaritalStatus] IS NULL OR ([MaritalStatus] IN ('W','S','D','M'))))
   END