INREC: Inserting sequence numbers

INREC: Inserting sequence numbers

Summary
  • To getback the original order of data before sort, a sequence number can be added to each record before therecords are sorted, and use a second step to sort the records back into theiroriginal order by that sequence number.
  • INREC statement can be used toadd the sequence number.

Syntax -

INREC FIELDS=(…,SEQNUM, length, format,..)
Name Description
SEQNUM A keyword specifies the sequence number to be generated from the next available position of INREC
Length Length of the sequence number to be generated
Format Format of the sequence number to be generated
Note! SUM can’t combine with COPY.

Example -

Scenario - Generate the sequence numbers to identify the record position before sorting using INREC.

Input File - MTHUSER.SORT.INPUT01 - FB file of 80 length 

----+----1----+---2----+---3----+---4----+---5----+---6---+----7----+---8
********************************* Top of Data *******************************
00001     student1           dept1          560            
00003     student3           dept2          520                   
00004     student4           dept1          540                 
00005     student5           dept2          500                    
00002     student2           dept3          510                     
******************************** Bottom of Data *****************************

JCL -

----+----1----+----2----+----3----+----4----+----5----+----6----+----7--
***************************** Top of Data ******************************
//Job-card 
//*                                                      
//*******************************************************************
//*                                                    
//* SORT FOR OUTREC STATEMENT                          
//*                                              
//*******************************************************************
//STEP01   EXEC PGM=SORT                                
//SORTIN   DD DSN=MTHUSER.SORT.INPUT01,DISP=SHR          
//SORTOUT  DD SYSOUT=*                                     
//SYSOUT   DD SYSOUT=*                                         
//SYSIN    DD *                                        
     SORT FIELDS=(1,5,ZD,A)                                 
     INREC FIELDS=(1,29,45,30,SEQNUM,4,ZD)                  
/*                                                         
**************************** Bottom of Data ***********************

Output File -

---+----1----+----2----+---3---+----4----+---5---+---6----+---7----+---8
********************************* TOP OF DATA *******************************
00001     student1           560                           0001  
00002     student2           510                           0005  
00003     student3           520                           0002     
00004     student4           540                           0003         
00005     student5           500                           0004  
******************************** BOTTOM OF DATA *****************************

Explaining Example -

  1. INREC FIELDS=(1,29,45,30) - Reformat the input file of length 80 to 59 bytes(1 to 29 bytes plus 45 to 75 bytes).
  2. INREC FIELDS=(..,SEQNUM,4,ZD)) - Generate the sequence number from 60th byte of length 4.
  3. SORT FIELDS=(1,5,ZD,A) - Once the above two tasks done, the file will sorted and the same writes to output after sorting.