Question

我有两个表产品和规格。在产品表中，它有像PhoneMake和PhoneModel和ProducId这样的列，而在规格中有像Os_name，Dapps，Os_ram，ProductId这样的列。我的问题是如何从所有这些中选择多个列值。像

select * 
  from product
where true 
  AND PhoneMake ='Motorola'
  AND PhoneMake ='Nokia '
  AND specs.Os_name ='on'
  AND specs.Os_name ='on'
  AND specs.Dapps ='on'
  AND specs.Os_ram =512 
  AND specs.Os_ram =1

什么是正确的mysql查询？

Answer 1

你必须了解联接：

select * from product join specs on <condition>
where PhoneMake in ('Motorola','Nokia') AND specs.Os_name ='on' AND specs.Dapps ='on'AND specs.Os_ram IN(512,1)

这是与表的简单连接。 <conditon>必须更改为specs和product之间的外键关系。

Answer 2

SELECT * 
  FROM product 
  INNER 
  JOIN specs 
    ON <condition>
 WHERE PhoneMake IN ('Motorola', 'Nokia ') 
   AND Os_name ='on' 
   AND Dapps ='on' 
   AND Os_ram IN (512, 1);

如何在mysql中使用不同的值从不同的表名中选择多个列？

2 个答案: