Mysql 如何进行此查询-GROUP_CONCAT
我想在Mysql 如何进行此查询-GROUP_CONCAT,mysql,sql,select,group-concat,Mysql,Sql,Select,Group Concat,我想在表a上执行选择,该表有: table_a: ╔══════════╦════════╗ ║ GROUP_ID ║ NAME ║ ╠══════════╬════════╣ ║ 1 ║ Tom ║ ║ 2 ║ Frank ║ ║ 3 ║ Shilla ║ ║ 1 ║ Scully ║ ║ 1 ║ Jen ║ ╚══════════╩════════╝ table_b: ╔════╦════════
表a上执行选择,该表有:
table_a:
╔══════════╦════════╗
║ GROUP_ID ║ NAME ║
╠══════════╬════════╣
║ 1 ║ Tom ║
║ 2 ║ Frank ║
║ 3 ║ Shilla ║
║ 1 ║ Scully ║
║ 1 ║ Jen ║
╚══════════╩════════╝
table_b:
╔════╦════════════╗
║ ID ║ GROUP_NAME ║
╠════╬════════════╣
║ 1 ║ Troopers ║
║ 2 ║ Clubs ║
║ 3 ║ Mavericks ║
╚════╩════════════╝
现在,我想显示给定成员名称的组:
SELECT GROUP_NAME,GROUP_CONCAT(table_a.NAME) MEMBERS
FROM table_a
JOIN table_b ON table_a.GROUP_ID = table_b.ID
WHERE
table_a.NAME = 'Scully'
我想得到这个:
╔════════════╦════════════════╗
║ GROUP_NAME ║ MEMBERS ║
╠════════════╬════════════════╣
║ Troopers ║ Tom,Scully,Jen ║
╚════════════╩════════════════╝
╔════════════╦════════════════╗
║ GROUP_NAME ║ MEMBERS ║
╠════════════╬════════════════╣
║ Troopers ║ Tom,Scully,Jen ║
╚════════════╩════════════════╝
为什么这个查询不起作用?我认为您的WHERE条件太有限了
WHERE table\u b.GROUP\u NAME='Troopers'
如果您只有一个成员的名称,则需要使用另一个联接获取组id:
试试这个:
SELECT table_b.GROUP_NAME, GROUP_CONCAT(table_a.NAME) MEMBERS
FROM table_a
JOIN table_b ON table_a.GROUP_ID = table_b.ID
JOIN table_b `temp` ON table_a.GROUP_ID = temp.ID
WHERE temp.NAME = 'Scully'
我认为你的条件太严格了
WHERE table\u b.GROUP\u NAME='Troopers'
如果您只有一个成员的名称,则需要使用另一个联接获取组id:
试试这个:
SELECT table_b.GROUP_NAME, GROUP_CONCAT(table_a.NAME) MEMBERS
FROM table_a
JOIN table_b ON table_a.GROUP_ID = table_b.ID
JOIN table_b `temp` ON table_a.GROUP_ID = temp.ID
WHERE temp.NAME = 'Scully'
为了获得更好的性能,请为表\u b.组\u名称
添加唯一的
约束
结果
为了获得更好的性能,请为表\u b.组\u名称
添加唯一的
约束
结果
我需要找到给定成员的组我需要找到给定成员的组你的结果仅限于Scully。也许你只是想限制史高丽的团体ID?你把结果限制在史高丽身上了。也许你只是想限制史高丽的团体身份?
SELECT
`group_name`,
GROUP_CONCAT(a.`name`) AS 'members'
FROM `table_a` a
INNER JOIN `table_b` b
ON a.`group_id` = b.`id`
AND a.`group_id` = (
SELECT `group_id` FROM `table_a` WHERE `name`='Scully'
)
GROUP BY NULL