dongqiu8375 2014-04-01 06:58
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使用查询获取父级和子级数据

I have 2 tables.

(1) taxes: Parent table

id title
1   service tax
2   vat

(2) cess_taxes: Child table

id  tax_id   title
1      2    cess vat
2      1    cess service
3      1    add. service

I want below data,

id title*
1 service tax (parent)
2 cess service (child)
3 add. service (child)
4 vat (parent)
5 cess vat (child)

How can i get data with using query???

I have tried with left, right & inner join

SELECT t.id, t.title, c.id, c.title
FROM `taxes` AS t
LEFT JOIN cess_taxes AS c ON c.tax_id = t.id
  • 写回答

1条回答 默认 最新

  • doubi8512 2014-04-01 07:10
    关注
    SET @rn:=0;
    SELECT @rn:=@rn+1 AS rank, title,id
    FROM (
      SELECT title,id
      FROM taxes
    
      Union
    
      SELECT c.title,
             case when t.id=1 then 1.5 else 3 end 
      FROM cess_taxes c
      inner join taxes t
        on t.id=c.tax_id
    
    
    ) t1
    Order By id
    

    SQL Fiddle Demo

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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