Need to write SQL to do what being done by 3 QUERY /400

Question

I have to write a Logical view or 2 to process legacy Query/400. The first query creates a temp file that is input to the second query (and second creates temp to the 3rd query). The purpose is that we want to see which customers do not have a 'correction' order which we get in the second query.

In the first query, it selects from OEINH1 and matches to Address_Table to get the customer email address, and selects on

T01.IHDOCD        DOCUMENT DATE                
T01.IHENT#        ENTITY NUMBER                
T01.IHSFX#        SUFFIX NUMBER                
T01.IHINV#        INVOICE NUMBER               
T02.ADINTA        INTERNET ADDRESS             

These columns and record selection:

IHORDT            EQ     'INT'        **** order type              
AND    IHVIAC            NLIST  'PML' 'FCM'               
AND    ADSFX#            EQ     '000'          

2. Second query matches on IHENT# (cust #) AND selects on this:

   IHORDT            LIST   'COR' 'COE'     
   

   and writes all columns from both the first temp and the same OEINH1 to a 2nd temp file.

This is problematic to redo this exactly in SQL because there are duplicate field names. Basically what is needed i think is to take the first temp file and then get the other 2 order types that this customer has (COR COE)

This sb something like this

Select * 
from TEMP FILE1 
where ENT in (Select * 
              from OEINH1 
              where IHORDT in ('COR' "COE')

does this make sense according to what the query/400 is doing?

The final QUERY/400 is then comparing the 2 temp files using UNMATCHED for the type of join. So then we can know which records are in the first pass but not in the second temp file.

Answer 1

Using Query to create a temporary file, then another Query to create another temporary file and finally a third query to process that file is kind of opposite of the way we think about SQL. SQL is about manipulating sets of records.

This is untested:

select h.IHDOCD, h.IHENT#, h.IHSFX#, h.IHINV#, a.ADINTA
from OEINH1 h 
  join Address_Table a
    on h.ihent# = a.customer_id
where h.IHORDT = 'INT'
  AND h.IHVIAC not in ('PML' 'FCM')
  AND ADSFX# = '000' 
  and h.ihent# in (
    select cor.ihent# 
      from oeinh1 cor
      where cor.IHORDT in ('COR' 'COE'))