GROUP是组,CONCAT合并多个字符串,它的功能是:将group by产生的同一个分组中的值连接起来,返回一个字符串结果 SUBSTRING_INDEX 截取字符串有效位数 select count(uid) as num, id,eid,created_at,uid, GROUP_CONCAT(created_at ORDER BY created_at DESC) AS created_at from ds_ask_person where eid=:eid ...
SELECTvo.year, SUBSTRING_INDEX( GROUP_CONCAT( vo.amount ), ",",1)ASm1, SUBSTRING_INDEX( SUBSTRING_INDEX( GROUP_CONCAT( vo.amount ), ",",2), ",",-1)ASm2, SUBSTRING_INDEX( SUBSTRING_INDEX( GROUP_CONCAT( vo.amount ), ",",-2), ",",1)ASm3, SUBSTRING_INDEX( GROUP_CONCAT( vo....
-1)) + (SUBSTRING_INDEX(SUBSTRING_INDEX(group_concat(sales_amount order by sales_amount), ',', ceiling(1 +((count(sales_amount)-1) / 2))), ',', -1)))/ 2 as median from sales s; show variables like 'group_concat_max_len'; --永久修改, group_concat_max_len=4294967295 --my...
SELECTYEAR,SUBSTRING_INDEX(GROUP_CONCAT(amount),",",1)ASm1,SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(amount),",",2),",",-1)ASm2,SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(amount),",",-2),",",1)ASm3,SUBSTRING_INDEX(GROUP_CONCAT(amount),",",-1)ASm4FROMtestsGROUPBYYEAR 执行结果 ...
SUBSTRING_INDEX( GROUP_CONCAT( vo.amount ), ",", - 1 ) AS m4 FROM tb_value_output vo GROUP BY vo.year 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 结果: year m1 m2 m3 m4 1991 1.1 1.2 2.2 2.5 1992 2.1 2.4 2.1 2.5 1.
在MySQL4.1中,加入了GROUP_CONCAT这个函数,我们就可以很 轻松的完成这个任务 SQL代码 SELECT`id`,GROUP_CONCAT(`name`ORDERBY`name`DESCSEPARATOR',')ASnameFROM`ta`GROUPBY`id` 但是如果要取得每个ID的前2个数据时即完成如下效果: +---+---+ | id ...
",", 1 ) AS m1,SUBSTRING_INDEX( SUBSTRING_INDEX( GROUP_CONCAT( amount ), ",", 2 ),",", -1 ) AS m2,SUBSTRING_INDEX( SUBSTRING_INDEX( GROUP_CONCAT( amount ), ",", - 2 ),",", 1 ) AS m3,SUBSTRING_INDEX( GROUP_CONCAT( amount ), ",", - 1 ) AS m4FROMtestsGROUP BYYEAR...
SUBSTRING_INDEX( SUBSTRING_INDEX( GROUP_CONCAT( amount ), ",",-2),",",1)ASm3, SUBSTRING_INDEX( GROUP_CONCAT( amount ), ",",-1)ASm4FROMtestsGROUPBYYEAR 1. 2. 3. 4. 5. 6. 7. 8. 9. 执行结果
mysql 记录 - concat、concat_ws、group_concat 的用法 2019-12-14 15:48 −本文中使用的例子均在下面的数据库表tt2下执行: 一、concat()函数 1、功能:将多个字符串连接成一个字符串。 2、语法:concat(str1, str2,...) 返回结果为连接参数产生的字符串,如果有任何一个参数为null,则返回值为null。 3...
【mysql】group_concat函数substring_index函数 2017-12-29 10:05 − 1、group_concat函数:用于将多个字符串连接成一个字符串 用法规则: SELECT GROUP_CONCAT(拼接的字段) from tableName; 使用:查询basic_project_vendor表的vendor_name字段,拼接成字符串返回 SELECT GROUP_C... howtosay 0 1680 mssql,...