Question

In a SQL server database, I have a table which contains a TEXT field which is set to allow NULLs. I need to change this to not allow NULLs. I can do this no problem via Enterprise Manager, but when I try to run the following script, alter table dbo.[EventLog] Alter column [Message] text Not null, I get an error:

Cannot alter column ‘ErrorMessage’ because it is ‘text’.

Reading SQL Books Online does indeed reveal you are not allow to do an ALTER COLUMN on TEXT fields. I really need to be able to do this via a script though, and not manually in Enterprise Manager. What are the options for doing this in script then?

Answer 1

You can use Enterprise Manager to create your script. Right click on the table in EM and select Design. Uncheck the Allow Nulls column for the Text field. Instead of hitting the regular save icon (the floppy), click an icon that looks like a golden scroll with a tiny floppy or just do Table Designer > Generate Change Script from the menu. Save the script to a file so you can reuse it. Here is a sample script:

    /* To prevent any potential data loss issues, you should review this script in detail before running it outside the context of the database designer.*/ BEGIN TRANSACTION SET QUOTED_IDENTIFIER ON SET ARITHABORT ON SET NUMERIC_ROUNDABORT OFF SET CONCAT_NULL_YIELDS_NULL ON SET ANSI_NULLS ON SET ANSI_PADDING ON SET ANSI_WARNINGS ON COMMIT BEGIN TRANSACTION GO CREATE TABLE dbo.Tmp_TestTable     (     tableKey int NOT NULL,     Description varchar(50) NOT NULL,     TextData text NOT NULL     )  ON [PRIMARY]      TEXTIMAGE_ON [PRIMARY] GO IF EXISTS(SELECT * FROM dbo.TestTable)      EXEC('INSERT INTO dbo.Tmp_TestTable (tableKey, Description, TextData)         SELECT tableKey, Description, TextData FROM dbo.TestTable WITH (HOLDLOCK TABLOCKX)') GO DROP TABLE dbo.TestTable GO EXECUTE sp_rename N'dbo.Tmp_TestTable', N'TestTable', 'OBJECT'  GO ALTER TABLE dbo.TestTable ADD CONSTRAINT     PK_TestTable PRIMARY KEY CLUSTERED      (     tableKey     ) ON [PRIMARY]  GO COMMIT