Plantilla para crear nuevos campos en SQL Server

-- Add new int field
IF NOT EXISTS(SELECT [Name] FROM syscolumns WHERE Name = 'FFFFFF' AND ID = OBJECT_ID('dbo.TTTTT'))
   ALTER TABLE TTTTT ADD FFFFFF INT NULL

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-- Add new nvarchar field
IF NOT EXISTS(SELECT [Name] FROM syscolumns WHERE Name = 'FFFFFF' AND ID = OBJECT_ID('dbo.TTTTT'))
   ALTER TABLE TTTTT ADD FFFFFF NVARCHAR(60) NULL

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-- Add new decimal field
IF NOT EXISTS(SELECT [Name] FROM syscolumns WHERE Name = 'FFFFFF' AND ID = OBJECT_ID('dbo.TTTTT'))
   ALTER TABLE TTTTT ADD FFFFFF DECIMAL(28,9) NULL

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-- Add new bit field (incl. update existing records with 0)
IF NOT EXISTS(SELECT [Name] FROM syscolumns WHERE Name = 'FFFFFF' AND ID = OBJECT_ID('dbo.TTTTT')) BEGIN
   ALTER TABLE TTTTT ADD FFFFFF BIT CONSTRAINT [rdf_TTTTT_FFFFFF] DEFAULT (0)
   EXEC ('UPDATE TTTTT SET FFFFFF = 0')
END

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-- Add new ntext field
IF NOT EXISTS(SELECT [Name] FROM syscolumns WHERE Name = 'FFFFFF' AND ID = OBJECT_ID('dbo.TTTTT'))
   ALTER TABLE TTTTT ADD FFFFFF NTEXT NULL

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