随笔分类 -  数据库

摘要:原文转载 https://www.cnblogs.com/wszz/p/9506035.html,详情请点击这个链接 MySQL数据库之MyISAM与InnoDB的区别 从以下几个方面: 1、存储结构 每个MyISAM在磁盘上存储成三个文件。第一个文件的名字以表的名字开始,扩展名指出文件类型。 .f 阅读全文
posted @ 2019-09-21 11:26 2538 阅读(223) 评论(0) 推荐(0)
摘要:sqlsrv: $UploaderID = strval( $_GET[ 'UploaderID' ] ); ///防止参数乱码$UploaderID = iconv( "UTF-8", "GB2312//IGNORE", $UploaderID ); ////sql语句 $sql = "SELEC 阅读全文
posted @ 2019-09-18 09:16 2538 阅读(560) 评论(0) 推荐(0)
摘要:SELECT TOP ( 3 ) A.Attentionnickname, B.HeadPhoto, B.BeattentionCount, ( SELECT COUNT( A.ID ) FROM A WHERE A.nickname = '小明' ) AS COUNT FROM A, B WHER 阅读全文
posted @ 2019-09-03 11:26 2538 阅读(435) 评论(0) 推荐(0)
摘要:先计算b表一个属性的平均分,然后插入a表中 。 UPDATE a SET a.perscore=(SELECT AVG(score) as avgFROM B WHERE resourceid=32) FROM A a,B b WHERE a.ID=b.resourceid AND b.resour 阅读全文
posted @ 2019-08-06 10:32 2538 阅读(258) 评论(0) 推荐(0)
摘要:MySQL: SELECT * FROM Table_Name ORDER BY RAND() LIMIT 6; SQL Server: SELECT TOP 6 * FROM Table_Name ORDER BY NEWID(); Oracle:SELECT * FROM (SELECT * F 阅读全文
posted @ 2019-07-08 15:25 2538 阅读(872) 评论(0) 推荐(0)