SQL Server 2005 drop column with constraints

Question

I have a column with a \"DEFAULT\" constraint. I\'d like to create a script that drops that column.

The problem is that it returns this error:

Msg 50         


        

Answer 1

Just to build on Jeremy Stein's answer, I created a stored procedure for this, and set it up so it can be used to delete a column that has or does not have default constraints. It's not real efficient since it's querying sys.columns twice, but it works.

CREATE PROCEDURE [dbo].[RemoveColumnWithDefaultConstraints] 
    -- Add the parameters for the stored procedure here
    @tableName nvarchar(max), 
    @columnName nvarchar(max)
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    DECLARE @ConstraintName nvarchar(200)
    SELECT @ConstraintName = Name 
    FROM SYS.DEFAULT_CONSTRAINTS 
    WHERE PARENT_OBJECT_ID = OBJECT_ID(@tableName) 
        AND PARENT_COLUMN_ID = (SELECT column_id FROM sys.columns WHERE NAME = (@columnName) 
        AND object_id = OBJECT_ID(@tableName))
    IF @ConstraintName IS NOT NULL
        EXEC('ALTER TABLE ' + @tableName + ' DROP CONSTRAINT ' + @ConstraintName)

    IF EXISTS(SELECT * FROM sys.columns WHERE Name = @columnName  
        AND Object_ID = Object_ID(@tableName))
        EXEC('ALTER TABLE ' + @tableName + ' DROP COLUMN ' + @columnName)       
END
GO