IF NOT EXISTS(SELECT 1 FROM SYSCOLUMNS WHERE ID = OBJECT_ID('EST_NF_ENT_IT_AUDIT') AND NAME = 'CD_NT_OP')
begin 
ALTER TABLE dbo.EST_NF_ENT_IT_AUDIT ADD
	CD_NT_OP int NULL
ALTER TABLE dbo.EST_NF_ENT_IT_AUDIT ADD CONSTRAINT
	DF_EST_NF_ENT_IT_AUDIT_CD_NT_OP DEFAULT 0 FOR CD_NT_OP
end