Question

我正在编写一个查询来提取员工和帐户信息。我保留了一个运行历史记录，每个员工在一个accounthistory表中没有重叠日期。我基本上试图提示我的用户他们想要该员工的员工/帐户的日期。因此，根据用户在运行时选择的日期选项，我需要我的连接是动态/条件的。这是我正在使用的当前查询，它在第3行＃51列上返回一个缺少的表达式错误。我仍在四处寻找，但我想我会问这里，以防有人已经取得了类似的东西。

（用户将通过应用程序填充：DATEOPTION变量。应用程序自动填充任何其他变量）

SELECT EMP.employeeid, ACT.accountname
FROM employee EMP
  LEFT OUTER JOIN accounthistory AHI ON (EMP.employeeid = AHI.employeeid AND CASE :DATEOPTION
                                         WHEN 1 THEN EMP.ppstartdatedtm BETWEEN AHI.effectivedtm AND AHI.expirationdtm
                                         WHEN 2 THEN EMP.ppenddatedtm   BETWEEN AHI.effectivedtm AND AHI.expirationdtm
                                         WHEN 3 THEN EMP.cpstartdatedtm BETWEEN AHI.effectivedtm AND AHI.expirationdtm
                                         WHEN 4 THEN EMP.cpenddatedtm   BETWEEN AHI.effectivedtm AND AHI.expirationdtm
                                         WHEN 5 THEN TO_DATE(:STARTDATETIME,'MM/DD/YYYY HH24:MI:SS') BETWEEN AHI.effectivedtm AND AHI.expirationdtm
                                         WHEN 6 THEN TO_DATE(:ENDDATETIME,'MM/DD/YYYY HH24:MI:SS')   BETWEEN AHI.effectivedtm AND AHI.expirationdtm END)
 INNER JOIN account ACT            ON (AHI.accountid = ACT.accountid

Answer 1

Oracle不支持case表达式可以返回的“boolean”类型。无论如何，不需要case：

ON EMP.employeeid = AHI.employeeidCASE AND
   ( (:DATEOPTION = 1 AND EMP.ppstartdatedtm BETWEEN AHI.effectivedtm AND AHI.expirationdtm) OR
     (:DATEOPTION = 2 AND EMP.ppenddatedtm BETWEEN AHI.effectivedtm AND AHI.expirationdtm) OR
     . . .
   )

Oracle条件加入声明

1 个答案: