Question

我的表格中包含Leave种类型Annual，Casual，Medical等。

现在我需要根据离开类型Annual Leave，Casual Leave，Medical Leave等将其拆分为多个列。

表LeaveAccount

LeaveAccountID, 
LeaveTypeID, 
EmployeeID, 
AccountingYearID, 
TotalLeaves, 
LeavesTaken

表LeaveType

LeaveTypeID,
LeaveTypeName

我的查询[给出一个无限循环]是：

[FullName，EmplyeeID，AnnualLeave，ShortLeave，Medical Leave]

SELECT
    e.FullName
  , e.EmployeeId
  , a.TotalLeaves as AnnualLeave
  , b.TotalLeaves as shortleave
  , c.TotalLeaves as MedicalLeave
FROM
    LeaveAccount a
  , Employee e
  , LeaveAccount b
  , LeaveAccount c
WHERE
      (a.EmployeeId = b.EmployeeId) 
  and (
            (a.LeaveTypeId = 0) 
        and (b.LeaveTypeId = 20)
        and (c.LeaveTypeId = 1)
      )

我是否需要使用动态SQL？怎么能分开我喜欢这个？

Answer 1

为什么需要拆分你的桌子？

当您可以创建表格的VIEWS时，每个视图将包含一列：

CREATE VIEW 
   Annual_Leave
AS 
SELECT 
   Annual
FROM 
   Leave types;

您对其余列执行相同操作。

Answer 2

尝试使用SubSelects：

SELECT
    e.FullName
  , e.EmployeeId
  , (SELECT SUM(a.TotalLeaves) FROM LeaveAccount a WHERE a.EmployeeId = e.EmployeeId AND a.LeaveTypeId = 0) AS "AnnualLeave"
  , (SELECT SUM(b.TotalLeaves) FROM LeaveAccount b WHERE b.EmployeeId = e.EmployeeId AND b.LeaveTypeId = 20) AS "ShortLeave"
  , (SELECT SUM(c.TotalLeaves) FROM LeaveAccount c WHERE c.EmployeeId = e.EmployeeId AND c.LeaveTypeId = 1) AS "MedicalLeave"
FROM
  Employee e

另一种解决方案是分组：

SELECT
    e.FullName
  , e.EmployeeId
  , SUM(a.TotalLeaves) AS "AnnualLeave"
  , SUM(b.TotalLeaves) AS "ShortLeave"
  , SUM(c.TotalLeaves) AS "MedicalLeave"
FROM
  Employee e
INNER JOIN
  LeaveAccount a
ON
      a.EmployeeId  = e.EmployeeId
  AND a.LeaveTypeId = 0
INNER JOIN
  LeaveAccount b
ON
      b.EmployeeId  = e.EmployeeId
  AND b.LeaveTypeId = 20
INNER JOIN
  LeaveAccount c
ON
      c.EmployeeId  = e.EmployeeId
  AND c.LeaveTypeId = 1
GROUP BY
    e.FullName
  , e.EmployeeId

修改：根据您的数据，您可能必须使用LEFT OUTER JOIN代替INNER JOIN。

通过过滤将一个特定列数据查看到多个列

2 个答案: