加入客户和标签表

加入客户和标签表

使用

exists()

让所有的客户和标签，当客户有指数1的标签：

select ct.customernumber, ct.tagindex, c.datefrom customers c  inner join customers_tags ct    on c.customernumber = ct.customernumberwhere exists (  select 1  from customers_tags i  where i.customernumber = ct.customernumber    and i.tagindex = 1  )

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或使用

in()

：

select ct.customernumber, ct.tagindex, c.datefrom customers c  inner join customers_tags ct    on c.customernumber = ct.customernumberwhere c.customernumber in  (  select i.customernumber  from customers_tags i  where i.tagindex = 1  )