IF NOT EXISTS (SELECT * FROM SYS.COLUMNS WHERE NAME = 'FLAG_TIPO_CONVERSAO' AND OBJECT_ID = OBJECT_ID('EST_PROD_FORN'))
begin	
ALTER TABLE dbo.EST_PROD_FORN ADD
	FLAG_TIPO_CONVERSAO int NULL

ALTER TABLE dbo.EST_PROD_FORN ADD CONSTRAINT
	DF_EST_PROD_FORN_FLAG_TIPO_CONVERSAO DEFAULT 0 FOR FLAG_TIPO_CONVERSAO
end
go
UPDATE
	EST_PROD_FORN
SET 
	FLAG_TIPO_CONVERSAO=0
WHERE
	FLAG_TIPO_CONVERSAO IS NULL