mysql 多张表做左连接操作 SQL应该如何写
问题如下,现一共有三张表,A表一条字段对应B表多条字段,B表多条字段对应C表多条字段,现在想查将A表左连接B表,接着左连接C表Sql语句应该是什么样的自己写了一个,但是报...
问题如下, 现一共有三张表, A表一条字段对应B表多条字段, B表多条字段对应C表多条字段,
现在想查将A表左连接B表,接着左连接C表
Sql语句应该是什么样的 自己写了一个,但是报error:1054错误
select dds.*, dsm.monsters_id, dsm.moster_id, dsm.pos
from
(select d.*, ds.stages_id, ds.mosters_id from dungeon_info as d LEFT JOIN dungeon_stage_info as ds on d.dungeon_id = ds.dungeon_id) as dds
LEFT JOIN
dungeon_stage_moster_info as dsm on dds.monsters_id = dsm.monsters_id 展开
现在想查将A表左连接B表,接着左连接C表
Sql语句应该是什么样的 自己写了一个,但是报error:1054错误
select dds.*, dsm.monsters_id, dsm.moster_id, dsm.pos
from
(select d.*, ds.stages_id, ds.mosters_id from dungeon_info as d LEFT JOIN dungeon_stage_info as ds on d.dungeon_id = ds.dungeon_id) as dds
LEFT JOIN
dungeon_stage_moster_info as dsm on dds.monsters_id = dsm.monsters_id 展开
3个回答
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error:1054 ???应该会明确告诉你那个字段什么的不存在吧,你检查一下?
为什么要用子查询呢,写一层sql查询就可以了啊。
select d.*,ds.stages_id, ds.mosters_id, dsm.monsters_id, dsm.moster_id, dsm.pos
from dungeon_info as d LEFT JOIN dungeon_stage_info as ds on d.dungeon_id = ds.dungeon_id
LEFT JOIN
dungeon_stage_moster_info as dsm on ds.monsters_id = dsm.monsters_id
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