need help sql query

I am having on开发者_JAVA技巧e query given below in that Employee, ShiftAllocation, ShiftMaster (two for two shift: Shift1 and shift2) table

SELECT     
   Em.EmployeeId, Em.EmployeeName,
   Sa.ShiftAllocationDate, Sa.ShiftId2, Sa.ShiftId, Sm.ShiftName,
   Sm2.ShiftName AS ShiftName2, Sa.ShiftAllocationId 
FROM        
   ShiftAllocation AS Sa 
INNER JOIN
   EmployeeMaster AS Em ON Sa.EmployeeId = Em.EmployeeId 
LEFT OUTER JOIN
   ShiftMaster AS Sm2 ON Sa.ShiftId2 = Sm2.ShiftId
LEFT OUTER JOIN
   ShiftMaster AS Sm ON Sa.ShiftId = Sm.ShiftId

I am getting this output:

 ShiftAlld EmployeeId  EmployeeName ShiftAllDate shiftId2 ShifId ShiftName ShiftName2 
   1           19          XYZ       2011-08-01 NULL     1     General    NULL
   2           19          XYZ       2011-08-02 NULL     1     General    NULL
   3           19          XYZ       2011-08-02 NULL    -1     NULL       NULL
   4           19          XYZ       2011-08-02 NULL     1     General    NULL
   5           19          XYZ       2011-08-02 NULL    -2     NULL       NULL
   6           19          XYZ       2011-08-02 NULL     1     General    NULL

I want

• shiftId -1 value should assign ShiftName as Week Off
• ShiftId -2 value should assign ShiftName as Holiday
• ShiftId2 NULL value should assign ShiftName2 as Not Assign

I want this output:

ShiftAlld EmployeeId  EmployeeName ShiftAllDate shiftId2 ShifId ShiftName ShiftName2 
   1           19          XYZ       2011-08-01 NULL     1     General    NotAssign  
   2           19          XYZ       2011-08-02 NULL     1     General    NotAssign  
   3           19          XYZ       2011-08-02 NULL    -1     WeekOff    NotAssign  
   4           19          XYZ       2011-08-02 NULL     1     General    NotAssign  
   5           19          XYZ       2011-08-02 NULL    -2     Holiday    NotAssign  
   6           19          XYZ       2011-08-02 NULL     1     General    NotAssign  

You can use a case something like this (untested so there may be any number of typos in there).

select Em.EmployeeId, 
       Em.EmployeeName,
       Sa.ShiftAllocationDate, 
       Sa.ShiftId2, 
       Sa.ShiftId, 
       case when sa.ShiftId = -1 then 'Week Off'
            when sa.ShiftId = -2 then 'Holiday'
            else sm.ShiftName
       end as ShiftName,
       case when sm2.ShiftId is null then 'Not assigned'
            else Sm2.ShiftName
       end as ShiftName2, 
       Sa.ShiftAllocationId 
from ShiftAllocation as Sa 
  inner join EmployeeMaster as Em 
    on Sa.EmployeeId = Em.EmployeeId 
  left outer join ShiftMaster as Sm2 
    on Sa.ShiftId2 = Sm2.ShiftId 
  left outer join ShiftMaster as Sm 
    on Sa.ShiftId = Sm.ShiftId

Although I am not sure if it would be the best way to do it; you can try using CASE in your sql to arrive at a solution.

Edit : This http://www.dba-oracle.com/t_case_sql_clause.htm should help you if you want to try.