MySQL 5.7版本sql_mode=only_full_group_by问题
用到GROUP BY 语句查询时com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'col_user_6.a.START_TIME' which is not functionally dependent on colu
0评论2023-02-10973
oracle与mysql的group by语句
之所以去纠那么细节的问题,是因为之前有过一个这样的场景:有个同学,给了一条数据库的语句给我,问,为啥这样子的语句在oracle语句下执行不了。1select * from xx where xxx is not null group by yy; 拿到这条语句的第一时间,其实,我也并没
0评论2023-02-10868
MySQL的SQL语句优化-group by语句的优化
原文:http://bbs.landingbj.com/t-0-243202-1.html 默认情况下,MySQL排序所有GROUP BY col1, col2, ....,查询的方法如同在查询中指定ORDER BY col1, col2, ...。如果显式包括一个包含相同的列的ORDER BY子句,MySQL可以毫不减速地对它进行优化,
0评论2023-02-09800
sql server 怎么实现mysql中group_concat,列转行,列用分隔符拼接字符串
create table tb(id int, value varchar(10))insert into tb values(1, 'aa') insert into tb values(1, 'bb') insert into tb values(2, 'aaa') insert into tb values(2, 'bbb') insert into tb values(2, 'ccc') goSEL
0评论2023-02-09437
详解SQL中Group By的用法
GROUP BY 语句用于结合合计函数,根据一个或多个列对结果集进行分组,记下来通过本文给大家介绍SQL中Group By的用法,需要的朋友参考下吧
0评论2016-04-2873