--创建测试表 if object_id(N'T_Test',N'U') is null CREATE TABLE [dbo].[T_Test] ( , ) PRIMARY key NOT NULL, ) NOT NULL, ) null, ) NULL ) GO --插入数据 , 'XXX') , 'XXX') , 'YYY') , null ) , '' ) insert into T_Test values('A', null, 'cc' ) insert into T_Test valu