SQL

[Mary Koetting <Mary_Koetting@xxxxxxxxxxxxxx>]

I'm new at SQL and would like for someone to please tell me if this
statement will do what I want.

The PRDHIST file has duplicate keys and is keyed on PHGRP, PHACCT, PHSSN,
PHPRID.

The COVMSTR is keyed on CVSSN CVGRP and CVACCT and it is a unique key.

PHPRID is a product ID and a person could have many products and many
different periods of coverage.

I want to join the PDTHIST with COVMSTR and pick up as many fields as I need
from the two files. I ordered it by the keys from PDTHIST plus the
termination date in descending order. (all records have termination dates
and only future dates are active records. I would like for the distinct
fields to be                 PHGRP
PHACCT
PHSSN
PHPRID but the SELECT statement seems to force you to list all fields that
you want to use. Can I restrict the DISTINCT fields to only certain fields
but still pick up other fields for use later in my program?. 

Is the WHERE statement used to join the files so you would always join the
two files with the keys and then add any additional
requirements/restrictions?

Any and all suggestion are greatly appreciated and please suggest a good
reference manual if you know of one. Thanks in advance. 
  
 EXEC SQL                                   
     DECLARE COBRA_CUR CURSOR FOR           
     SELECT DISTINCT                        
         A.PHGRP,                           
         A.PHACCT,                          
         A.PHSSN,                           
         A.PHEDCY,                          
         A.PHEDYR,                          
         A.PHEDMT,                          
         A.PHEDDY,                          
         A.PHTDCY,                          
         A.PHTDYR,                          
         A.PHTDMT,                          
         A.PHTDDY,                          
         A.PHPRID,                          
         A.PHTRFC,                          
         A.PHGGAO,                                           
         B.CVTRCD                                            
      FROM PDTHIST A, COVMSTR B                               
      WHERE (A.PHGRP = B.CVGRP)                               
      AND   (A.PHSSN = B.CVSSN)                               
      AND   (A.PHACCT = B.CVACCT)                             
      AND   (A.PHTRFC = :COBPO                                
      OR     A.PHTRFC = :COBPS                                
      OR     A.PHTRFC = :COBPC                                
      OR     A.PHTRFC = :COBPF                                
      OR     A.PHTRFC = :COBCO)                               
      AND   (DIGITS(A.PHTDCY)||DIGITS(A.PHTDYR)||             
            DIGITS(A.PHTDMT)||DIGITS(A.PHTDDY) > :TODAYS-DATE)
      ORDER BY A.PHGRP,                                       
               A.PHACCT,                                      
               A.PHSSN,
               A.PHPRID,                                       
               A.PHEDCY DESC,                                 
               A.PHEDYR DESC,     
               A.PHEDMT DESC,     
               A.PHEDDY DESC      
  END-EXEC.                       
 

                                         
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