SQL SELECT查詢（員工和崗位）

1）表位置

pos_id, pos_description, pos_total(maximum # of employees for that position) 

    1  c++ Developer  3 
    2  Java Developer 2 
    3  DBA    3

2）表員工

emp_id, emp_pos_id 
1  1 
2  1 
3  2 
4  3 
5  3 
6  3

我想創建以下報告在SQL Server或Sybase中：

Position Pos. Description  Serial No of Position ID of Employee 
    1  C++ Developer  1      1 
    1  C++ Developer  2      2 
    1  C++ Developer  3      ------------------ 
    2  Java Developer  1      3 
    2  Java Developer  2      ------------------ 
    3  DBA     1      4 
    3  DBA     2      5 
    3  DBA     3      6

我該如何實現這樣的查詢？

來源

2012-06-20 klgr

所需的基本查詢看起來像：

select p.pos_id, p.pos_description, 
     row_number() over (partition by p.pos_id order by e.emp_id) as SerialNumber, 
     e.emp_id 
from positions p left outer join 
    employees e 
    on p.pos_id = e.emp_pos_id 
order by 1, 2, 3

的問題是，這不返回空位置。因爲，可以想象，每個職位都可能是空的，在這種情況下需要什麼？

select p.pos_id, p.pos_description, 
     row_number() over (partition by p.pos_id order by p.pos_id) as SerialNumber, 
     NULL as emp_id 
from position p join 
    (select row_number() over (partition by NULL order by pos_id) as seqnum 
     from positions 
    ) as numbers 
    on numbers.seqnum <= p.pos_total

在這裏，我只是使用表來創建一個數字列表。我加入到這些職位。

下一個查詢使用連接結合了其中兩個：

with byemp as (
    select p.pos_id, p.pos_description, 
      row_number() over (partition by p.pos_id order by e.emp_id) as SerialNumber, 
      e.emp_id 
    from positions p left outer join 
      employees e 
      on p.pos_id = e.emp_pos_id 
    ), 
allpos as (
    select p.pos_id, p.pos_description, 
      row_number() over (partition by p.pos_id order by p.pos_id) as SerialNumber, 
      NULL as emp_id 
    from position p join 
      (select row_number() over (partition by NULL order by pos_id) as seqnum 
      from positions 
      ) as numbers 
      on numbers.seqnum <= p.pos_total 
    ) 
select allpos.pos_id, allpos.pos_description, allpos.SerialNumber, 
     coalesce(byemp.emp_id, allpos.emp_id) as emp_id 
from allpos join 
    byemp 
    on allpos.pos_id = byemp.pos_id and 
     allpos.SerialNumber = byemp.SerialNumber

基本上，它是保持從allpos所有的位置信息，而是從byemp帶來的EMPID可用時。

來源

2012-06-20 16:03:03

那麼該查詢的情況下，失敗時位置的錶行的總數小於pos_total。在將DBA位置的pos_total更新爲4之後，運行上面的示例。它不會爲DBA生成4個空白行，它應該有.. –

非常感謝。我將最後一個JOIN修改爲LEFT JOIN並且它正在工作 – klgr

在SQL Server：

;WITH DummyTable AS (
    SELECT 1 AS Value 
    UNION ALL 
    SELECT Value + 1 
    FROM DummyTable 
    WHERE Value < 1000 --This value must be least as large as the largest "maximum # of employees for that position" 
) 
SELECT p.pos_id Position, p.pos_description [Pos. Description], n.Value [Serial No of Position], emp_id [ID of Employee] 
FROM DummyTable n 
    INNER JOIN Positions p 
     ON n.Value <= p.pos_total 
    LEFT JOIN (SELECT emp_id, emp_pos_id, ROW_NUMBER() OVER(PARTITION BY emp_pos_id ORDER BY emp_id) AS emp_position FROM Employees) e 
     ON e.emp_pos_id = p.pos_id 
     AND e.emp_position = n.Value 
ORDER BY p.pos_id, n.Value 
OPTION (MAXRECURSION 0);

來源

2012-06-20 16:24:55

這會工作，假設公司永遠不會有超過1000名員工給定位置... –

with mycte 
as 
(
select * from pos p inner join dbo.nums n on p.nums >= n.cnt 
) , 
em as (select empid,empposid,ROW_NUMBER() over(PARTITION by empposid order by empid) as rn  from emp) 
select mc.id as positionid,mc.descr,mc.cnt,isnull(convert(varchar(30),e.empid),'------------') 
from mycte mc 
left join em e on mc.id= e.empposid 
and e.rn = mc.cnt

試試這個NUMS表只是conating值的表1到100萬

來源

2012-07-13 19:37:53

SQL SELECT查詢（員工和崗位）

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