How to alter all columns of a table in SQL SERVER

To alter all columns of a table :

 

DECLARE @SQL VARCHAR(MAX)

SET @SQL = (

SELECT '

ALTER TABLE dbo.yourtablename ALTER COLUMN [' + c.name + '] NVARCHAR(MAX) NULL;

'

FROM sys.columns c WHERE OBJECT_NAME(object_id) = 'yourtablename'

FOR XML PATH(''), TYPE

).value('text()[1]', 'VARCHAR(MAX)')

 

--PRINT @SQL

 

EXEC(@SQL)