动态SQL应用小列子
呵呵,几乎成标题党了,今天要写个脚本查询7天内所有有登录玩家的数据,要求按注册日期统计,虽然是个简单的问题,但是关键是用户表有30个,分别是user0, user1......到user29 ,光是把它们UNION ALL起来,我都够郁闷了,你想象下脚本有多长吧,一大堆堆在那儿,光是复制都让你难以忍受。http://common.cnblogs.com/images/copycode.gif
SELECT Id,CONVERT(VARCHAR(10),Create_Time, 120), Last_Login_Time FROM user0
UNION ALL
SELECT Id,CONVERT(VARCHAR(10),Create_Time, 120), Last_Login_Time FROM user1
UNION ALL
SELECT Id,CONVERT(VARCHAR(10),Create_Time, 120), Last_Login_Time FROM user2
.........
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呵呵,下面是我用动态SQL 改写的,呵呵,简洁多了
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DECLARE @cmdText VARCHAR(8000);
DECLARE @userIndex INT;
SET @cmdText = '';
SET @userIndex = 0;
WHILE @userIndex
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