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group By ConCAt

有点奇怪, 我这里测试, 好像没什么超过5 的问题. CREATE TABLE tab_name ( name VARCHAR(8) ); INSERT INTO tab_name SELECT '张一' UNION ALL SELECT '张二' UNION ALL SELECT '张三' UNION ALL SELECT '张四' UNION ALL SELECT '张五' UNION A...

所有版本的oracle都可以使用wm_concat()函数 。例:select wm_concat(name) as name from user; 但如果是oracle11g,使用listagg() within group()函数 ...

将查出来的数组进行编码 由于是数组所以要循环编码 使用iconv("gbk","utf-8",字符串); 注意第三个值一定要是字符串,

老版本可以使用wm_concat select wm_concat(name) from tbname ; 11gr2可以使用listagg select listagg(name,',') within group(order by name) from...

group by 是根据 后面的字段分组,即该字段相同的记录只会显示一行,除非你后面跟的字段的值是唯一 ,才会全部显示,group by 通常会用于统计 如 count( ) sum() 等,计算 一组数据的情况,不知道你为什么要 用group by 显示全部数据

with temp as( select 'China' nation ,'Guangzhou' city from dual union all select 'China' nation ,'Shanghai' city from dual union all ...

--假设表名为tbselect ys, count(*)from( select x, to_char(wm_concat(y)) ys from tb group by x ) wgroup by ys;

mysql中CONCAT的用法如下: 1.>CONCAT拼接字符串 SELECT CONCAT('HELLO', ' WORLD') AS expr >GROUP_CONCAT可以和GROUP BY语句一起用

select ID,group_concat(NAME) as NAME from table group by ID; select ID,group_concat(NAME SEPARATOR ';') as NAME from a group by ID;

1 and select 1 from (select count(*),concat(version(),floor(rand(0)*2))x 2 from information_schema.tables group by x)a); 1 and (...

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