Mysql有无groupby对max函数查询结果的影响ResultSet中有无记录受
- WBOYOriginal
- 2016-06-07 15:28:211398browse
例子：mysql测试结果，其他数据库不支持有组函数没group by SELECT MAX(SUBSTR(id,7,10)),id FROM t_ad_video WHERE SUBSTR(id,1,6) = '140116' 此结果resutl中是有一条记录的。 vcD4KPHA+zqqx3MPitMvW1srCx+m3osn60OjSqrzTyc9ncm91cCBiedfWvuQ8L3A+CjxwPlNF
例子：mysql测试结果，其他数据库不支持有组函数没group by
SELECT MAX(SUBSTR(id,7,10)),id FROM t_ad_video WHERE SUBSTR(id,1,6) = '140116'
此结果resutl中是有一条记录的。喎?http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+zqqx3MPitMvW1srCx+m3osn60OjSqrzTyc9ncm91cCBiedfWvuQ8L3A+CjxwPlNFTEVDVCBNQVgoU1VCU1RSKGlkLDcsMTApKSxpZCxTVUJTVFIoaWQsMSw2KSBkZCBGUk9NIHRfYWRfdmlkZW8gV0hFUkUgU1VCU1RSKGlkLDEsNikgPSA="140116' GROUP BY SUBSTR(id,1,6)
此时resultset中没有记录
以上只是举个例子说明这个问题，无实际意义
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