IF NOT EXISTS(SELECT 1 FROM syscolumns WHERE ID = OBJECT_ID('EST_NF_ENT_IT') AND NAME = 'FLAG_N_GERAR_DAR')
begin
	ALTER TABLE dbo.EST_NF_ENT_IT ADD
		FLAG_N_GERAR_DAR int NULL

	ALTER TABLE dbo.EST_NF_ENT_IT ADD CONSTRAINT
		DF_EST_NF_ENT_IT_FLAG_N_GERAR_DAR DEFAULT 0 FOR FLAG_N_GERAR_DAR
end