SQL Union all 语句答案

【问题标题】：SQL Union all statementSQL Union all 语句
【发布时间】：2013-09-01 14:02:00
【问题描述】：

我使用 UNION ALL 加入了 4 条 sql 语句。

由于WHERE条件相同，是否可以将WHERE条件合二为一？

select 'Transfer In' as MovementType, * from vHRIS_StaffMovement_TransferIn 
where cur_deptid in (1,2,3,4,5)
        and cast(EffectiveDate as date) <='2013-08-02'
        and cast(EffectiveDate as date) >= '2012-08-01'
        and StaffType in (1,2,3,4,5)

union all

        select 'Terminate' as MovementTyep, * from vHRIS_StaffMovement_Terminate  
where cur_deptid in (1,2,3,4,5)
        and cast(EffectiveDate as date) <='2013-08-02'
        and cast(EffectiveDate as date) >= '2012-08-01'
        and StaffType in (1,2,3,4,5)

union all

        select 'New Hire' as MovementTyep, * from vHRIS_StaffMovement_NewHire 
where cur_deptid in (1,2,3,4,5)
        and cast(EffectiveDate as date) <='2013-08-02'
        and cast(EffectiveDate as date) >= '2012-08-01'
        and StaffType in (1,2,3,4,5)      

union all

select 'Transfer Out' as MovementType, * from vHRIS_StaffMovement_TransferOut 
where cur_deptid in (1,2,3,4,5)
        and cast(EffectiveDate as date) <='2013-08-02'
        and cast(EffectiveDate as date) >= '2012-08-01'
        and StaffType in (1,2,3,4,5)

【问题讨论】：

标签： sql union where-clause union-all

【解决方案1】：

你可以这样做：

    select * from (
        select 'Transfer In' as MovementType, * from vHRIS_StaffMovement_TransferIn 
        union all
        select 'Terminate' as MovementTyep, * from vHRIS_StaffMovement_Terminate  
        union all
        select 'New Hire' as MovementTyep, * from vHRIS_StaffMovement_NewHire 
        union all
        select 'Transfer Out' as MovementType, * from vHRIS_StaffMovement_TransferOut ) as a
where cur_deptid in (1,2,3,4,5)
        and cast(EffectiveDate as date) <='2013-08-02'
        and cast(EffectiveDate as date) >= '2012-08-01'
        and StaffType in (1,2,3,4,5)

【讨论】：

【解决方案2】：

您可以使用子查询：

SELECT X.* 
FROM   (SELECT 'Transfer In' AS MovementType, * 
        FROM   vhris_staffmovement_transferin 

        UNION ALL 

        SELECT 'Terminate' AS MovementTyep, * 
        FROM   vhris_staffmovement_terminate 

        UNION ALL 

        SELECT 'New Hire' AS MovementTyep,  * 
        FROM   vhris_staffmovement_newhire

        UNION ALL 

        SELECT 'Transfer Out' AS MovementType, * 
        FROM   vhris_staffmovement_transferout ) X 
WHERE  cur_deptid IN ( 1, 2, 3, 4, 5 ) 
       AND Cast(effectivedate AS DATE) <= '2013-08-02' 
       AND Cast(effectivedate AS DATE) >= '2012-08-01' 
       AND stafftype IN ( 1, 2, 3, 4, 5 )

【讨论】：

【解决方案3】：

你可以试试这个：

SELECT *
  FROM T_IP_CHARGES WITH (NOLOCK)
  WHERE PostingDate BETWEEN '01/01/2014' AND '01/31/2014'
    AND DetailTotalCharges > 0
  UNION ALL
  SELECT *
  FROM T_OP_CHARGES WITH (NOLOCK)
  WHERE PostingDate BETWEEN '01/01/2014' AND '01/31/2014'
  AND DetailTotalCharges > 0

【讨论】：