>>>>>

>>>>>       DECLARE @aaa varchar(200)
>>>>>       SELECT  @aaa = OBJECT_NAME(constid) FROM sysconstraints WHERE OBJECT_NAME(Id) = 'YourTableName' AND OBJECT_NAME(constid) LIKE '%YourColumnName%'
>>>>>       IF @aaa IS NOT NULL
>>>>>          BEGIN
>>>>>              SET @aaa = 'ALTER TABLE YourTableName DROP CONSTRAINT '+@aaa
>>>>>              EXEC (@aaa)
>>>>>          END
>>>>>
>>>>>
>>>>>       ALTER TABLE YourTableName ALTER COLUMN ....
>>>>>

>>>>
>>>>Borislav,
>>>>
>>>>Thank you very much! You code works. However the resulting column loses the default constraint and accepts NULL.
>>>>Do I have to create the default constraint, after your code, and then Alter the column and remove the NULL?
>>>
>>>DROP constraint first if it exists, create not nullable column with the default constraint (you can use the same name for constraint as before)
>>
>>Thank you.
>
>You could define your column with the ALTER TABLE command:
>

>ALTER TABLE ... ALTER COLUMN .... varchar(max) NOT NULL CONSTRAINT DF_TableName_ColumName DEFAULT ''
>

Can you think of why I am getting the error on the CONSTRAINT? The line is underlined with red and the error:

Incorrect syntax near the keyword 'CONSTRAINT'.