Criando campos na tabela

DECLARE @OBJECT_ID INT

SELECT @OBJECT_ID=OBJECT_ID FROM SYS.OBJECTS WHERE TYPE_DESC = 'USER_TABLE' AND NAME = 'TB_FWE_CONFIGURACAO_PAGAMENTO'

IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE OBJECT_ID=@OBJECT_ID AND NAME='PAGSEGURO_DS_EMAIL' )

BEGIN

ALTER TABLE TB_FWE_CONFIGURACAO_PAGAMENTO

ADD PAGSEGURO_DS_EMAIL VARCHAR(150) NULL;

END