[SOLVED] Not Equal to in Inner Join

Not Equal to in Inner Join

I have 3 scenarios to implement.

Case 1- When IM.Code=IME.Code and IM.Effective_st_dt=IME.effective_st_dt and IM.Effective_end_dt =IME.Effective-end_date

Action- In this case i need to update the IM with currentMrp and currentCp.

Case 2- When IM.Code=IME.Code and IM.Effective_st_dt!=IME.effective_st_dt and IM.Effective_end_dt =IME.Effective-end_date

Action- 1.)Pick the recent Effective_st_dt record from IM and Update the Effective_end_date with (IME.Effective_st_dt)-1

2.)then Insert a new record from IME which has new effective_st_dt also this record lastMRP and lastcp is the currentmrp and Currentcp of the previous record which is updated in 1

Case 3- When IM.Code=IME.Code and IM.Effective_st_dt!=IME.effective_st_dt and IM.Effective_end_dt !=IME.Effective-end_date

Action- 1.)Pick the recent Effective_st_dt record from IM and Update the Effective_end_date with (IME.Effective_st_dt)-1

2.)then Insert a new record from IME which has new effective_st_dt also this record lastMRP and lastcp is the currentmrp and Currentcp of the previous record which is updated in 1

This is the script of my tables

Create Table IM 
(
    ID int idenetity (1,1)
    ,Code varchar(100)
    ,CurrentMrp float
    ,CurrentCP float
    ,lastMrp float
    ,lastCp float
    , effective_st_dt date
    ,effective_end_dt date
)

Create table IME
(
    Code varchar(100)
    ,CurrentMrp float
    ,CurrentCP float
    ,Effective_st_dt date
    ,Effective_end_dt date
)

insert into IM (code, currentMrp, currentCp, lastMRP, lastCP, effective_st_dt, effective_end_dt)
   Select 
      'CA123', 10.12, 5.0, 8.20, 4, '2014-05-01', '2014-05-31'
   union
Select 'CA123',15.0,5.0,10.12,8.20,'2014-06-01','2014-08-31'
union
Select 'CA121',50.0,15.0,45.0,25.0,'2014-04-01','2014-05-31'
union
Select 'CA121',75.0,25.0,50.0,15.0,'2014-06-01','2014-06-30'
union
Select 'CA131',53.0,12.0,35.0,10.0,'2014-05-01','2014-05-31'
union
Select 'CA131',60.0,15.0,53.0,12.0,'2014-06-01','2014-08-31'


Insert into IME (code,effective_st_dt,effective_end_dt)
Select ('CA123',20.0,5.0,'2014-06-01','2014-08-31')
union
Select ('CA123',25.0,6.0,'2014-06-20','2014-08-31')
union
Select ('CA123',35.0,7.0,'2014-07-15','2015-03-31')

please help me to solve this

Your help is appreciated

Solution

its better you use left join instead of inner join in this particular case, else not equal to will not give you the correct results.