我的MySQL查询有问题,可能还有加入。
我的数据库结构如下:
Table A
id, nameA, nameB
Table B
some_stuff, ids
第二个表中的 ids
是一个字符串,其中包含第一个表中的一个或多个id
我想从两行获取数据,例如:
Result
some_stuff, ids, firstId, firstNameA, firstNameB
some_stuff, ids, secondId, secondNameA, secondNameB
是否可以使用单个查询获取它,可能不使用子查询?
答案 0 :(得分:0)
选中此sqlfiddle
<强>查询:强>
SELECT some_stuff, ids, id, nameA, nameB FROM TabA JOIN TabB ON INSTR(ids, id)
表格结构:
CREATE TABLE IF NOT EXISTS `TabA` (
`id` int(8) unsigned NOT NULL AUTO_INCREMENT,
`nameA` varchar(128) CHARACTER SET utf8 NOT NULL DEFAULT '',
`nameB` varchar(16) CHARACTER SET utf8 NOT NULL DEFAULT '',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `TabB` (
`bid` int(8) unsigned NOT NULL AUTO_INCREMENT,
`ids` varchar(128) CHARACTER SET utf8 NOT NULL DEFAULT '',
`some_stuff` varchar(16) CHARACTER SET utf8 NOT NULL DEFAULT '',
PRIMARY KEY (`bid`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
INSERT INTO TabA(id,nameA,nameB) VALUES(1,"nm1","nmm1"),
(2,"nm2","nmm2"),
(3,"nm3","nmm3"),
(4,"nm4","nmm4"),
(5,"nm5","nmm5");
INSERT INTO TabB(bid,ids,some_stuff) VALUES(1,"1,2","some_stuff1"),
(2,"1,3","some_stuff2"),
(3,"2","some_stuff3"),
(4,"2,4","some_stuff4"),
(5,"1,2,3","some_stuff5");
输出
SOME_STUFF IDS ID NAMEA NAMEB
some_stuff1 1,2 1 nm1 nmm1
some_stuff1 1,2 2 nm2 nmm2
some_stuff2 1,3 1 nm1 nmm1
some_stuff2 1,3 3 nm3 nmm3
some_stuff3 2 2 nm2 nmm2
some_stuff4 2,4 2 nm2 nmm2
some_stuff4 2,4 4 nm4 nmm4
some_stuff5 1,2,3 1 nm1 nmm1
some_stuff5 1,2,3 2 nm2 nmm2
some_stuff5 1,2,3 3 nm3 nmm3
如果有任何错误让我知道。