sqlserve更新
1、交换列
create table AAA_Test1 ( A int null, B int null, ); insert into AAA_Test1 values(1,2); select * from AAA_Test1 update AAA_Test1 set A=B,B=A;
不需要临时变量就可以交换。
2、更新
update AAA_Test1 set A=B,B=null delete AAA_Test1 insert into AAA_Test1 values(1,2); update AAA_Test1 set B=null,A=B
更新结果都一样,和字段顺序无关,都是先更新表内部赋值,在更新外部赋值