Question

我在数据库中有三个表：makers，parts，transfers。

Makers是 makerid,stampname

Parts是 categories,name

variations是 id, provider, recipient, part

Provider是指向makers/makerid的指针，因此recipients。

我需要查询，以便我的结果显示友好名称与编码/简化数据库ID。

我尝试了几个连接，但我的查询：

select makers.stampname as giver, makers.stampname as takers
from makers
   left join variations prov on prov.provider=makers.makerid
   left join variations recp on recp.recipient=makers.makerid limit 5;

在两列中生成相同的名称。如果provider为makerid 24且recipient为makerid 10，我如何获取查询以回复来自{{1}的重合stampname db？

Answer 1

抱歉，看起来需要更好地理解别名。这非常有效：

select variations.date,provider.stampname as provname ,
recipient.stampname as recipname, 
parts.name from variations 
left outer join 
makers provider on variations.provider = provider.makerid 
left outer join 
makers recipient on variations.recipient = recipient.makerid
left join categories parts on variations.part = parts.catid 
where variations.provider = "20" 
and 
variations.date="1944";

加入多个mysql表

1 个答案: