SQL 技巧贴

利用Case when动态设置过滤条件

SELECT * FROM TABLEA WHERE ID=(CASE WHEN NAME='张三' THEN 1 WHEN '李四' THNE 2 ELSE 0 END)

Update、Delete利用join批量更新或删除

update t1 set t1.name=’Liu’ from t1 inner join t2 on t1.id = t2.tid

delete from t1 from t1 inner join t2 on t1.id = t2.tid

 int转varchar类型，并格式化为4位数，不足前面补0

select right('0000'+CAST(USER_INT_ID as varchar(10)),4) FROM COMMON_UserInfo

 ROW_NUMBER()的使用

http://www.cnblogs.com/fxgachiever/archive/2010/09/15/1826792.html

查看连接数据库的线程

select * from master.sys.sysprocesses where dbid=db_id('') and status='runable'