1. 28 10-1 Structured COBOL Programming Nancy Stern Hofstra University Robert A. Stern Nassau Community College James P. Ley University of Wisconsin-Stout John Wiley & Sons, Inc. PowerPoint Winifred J. Rex Presentation Bowling Green State University 10th edition

2. 28 10-2 Control Break Processing Chapter 10

3. 28 10-3 Chapter Objectives To familiarize you with Main types of computer-generated reports Techniques used for efficient printing of group reports and control totals  Control break processing and control break printing

4. 28 10-4 Chapter Contents Introduction to Control Break Processing Program Requirements for Control Break Processing  Multiple-Level Control Breaks –Program 5

5. 28 10-5 Types of Reports Detail or Transaction Reports –Include one or more lines of output for each input record read Exception Reports –Printout of individual records that meet (or fail to meet) certain criteria Summary Reports –Summarizes rather than itemizes to provide more comprehensive information

6. 28 10-6 Control Break Processing Produces summary report using control fields to indicate when totals are to print Records with same value for control field grouped together in file Totals printed for each group of records with same control field value

7. 28 10-7 Control Break Example Consider file of sales records, each with three fields: –Salesperson's department number, salesperson's number, sales amount Department number is control field Records in sequence by control field –All records for salespeople in Dept 01 followed by records for those in Dept 02, …

8. 28 10-8 Sample Sales Input Data 01 12345 098855 01 12346 353700 01 12347 003499 02 12222 987700 02 12234 008777 Amt-Of-Sales-In SlsNo-In (Salesman Number) Dept-In Note: data is SORTED!!!

9. 28 10-9 Control Break Example Report includes detail printing –One line for each record with salesperson's amount of sales Report also includes summary lines or group printing –Total line written for each department –After all records for Dept 01 read and printed, total for Dept 01 printed –Same is done for Dept 02, and so on

10. 28 10-10 Control Break Sample Report Dept Salesperson No Amt of Sales 0112345$988.55 0112346$3,537.00 0112347 $34.99 Total for Dept is$4,560.54 0212222$9,877.00 0212234$87.77 Total for Dept is$9,964.77

11. 28 10-11 Control Break Example Records must be in sequence by some control field (department number) –Here, dept number –Could be classification (frosh, soph, junior, …) –Any kind of meaningful classification… Sales records for Dept 01 read in, printed, Dept total accumulated Continues until record read in with different Dept number Change in Dept triggers printing of Dept total for Dept 01 May want a grand total for all departments at the end too.

12. 28 10-12 Single-Level Control Break Single-level means program has only one control field whose value triggers printing of totals Control break occurs when there is change in control field value from one record to the next –Recall: data is sorted.

13. 28 10-13 Single-Level Control Break Many steps (initialization, heading routines) same as previous programs  Detail routine must be modified to check for control breaks  New module added to handle control break processing

14. 28 10-14 Detecting a Control Break For first record read, move control field to hold area in WORKING-STORAGE –Then process this record. If control field of subsequent records is same as hold area –Perform detail processing If they are not equal, control break occurs –Perform control break routine

15. 28 10-15 Detail Processing When control field is equal to hold area Add amount to control total or other values that are being accumulated… Print detail record (if desired) Read next record Continue until there is a change in the value of the control field.

16. 28 10-16 Control Break Routine If control field of record read is not equal to hold area, you must suspend normal record processing to handle the control break: –Print control total for previous group –Initialize control total field to zero –Reinitialize hold field with new control field value of the record just read, Perform detail processing of this new ‘first’ record and proceed as before.

17. 28 10-17 Handling first record First record has no previous control field value for comparison Add field to use as "flag" to determine if record is first one processed (e.g., First- Record initialized to 'YES') When record read, if First-Record = 'YES' –Save control field value in hold area –Turn "off" flag by setting it to 'NO'

18. 28 10-18 Forcing Final Control Break Totals printed when record with new control field is read Last group of records has no subsequent record to trigger printing because we hit end of file. Include statements in end of job routine to move final group total to output record and print it with its totals as you would on a normal control break.

19. 28 10-19 Printing a Final Total May accumulate final total by –Adding amount from each record to “control group total” and “final total” in detail routine –Adding control group total to final total in control break routine Second method more efficient since additions made once for each group instead of once for each record

20. 28 10-20 Multiple Level Control Breaks Suppose a sales record is created each time a salesperson makes a sale Each salesperson may have multiple sales records Report will include two levels of totals –Total sales for each salesperson –Total sales for each department

21. 28 10-21 Multiple Level Control Breaks Two control fields: Dept-In and SlsNo-In Records sorted by major control field (Dept-In) Within department, sorted by minor control field (SlsNo-In)

22. 28 10-22 Sample Sales Input Data Dept-In SlsNo-In Amt-Of-Trans-In 01 004 127.23 01 004 100.14 01 006 027.45 01 006 052.23 01 006 126.27 02 003111.14 02003027.23 In sequence within Dept 01 Discuss the sort sequence…

23. 28 10-23 Double-Level Control Break Two hold areas, one for each control field  Check for control break on each –If no change in Dept-In or SlsNo-In, just add Amt- Of-Trans-In to salesperson total –If Dept-In changes, perform major control break routine –If no change in Dept-In but SlsNo-In changes, perform minor control break routine –  But this requires care, especially when printing totals, resetting control variable values (for next record) and clearing accumulators for the minor break without messing up the totals for the major break.

24. 28 10-24 Major Control Break Routine Begins by forcing minor control break –This processes last salesperson’s total for previous department –Do all that is required for a single control break based on salesman number…. –This may involve printing salesman totals, etc…Now: Print department total Reinitialize department total to zero Save new Dept-In in hold area Print heading for new department and all that. Note: you will likely have a new department. Don’t forget EOF considerations, which will force both a major and minor control break.

25. 28 10-25 SORTED INPUT FILE - FOR DEMO ON SINGLE CONTROL BREAK \DEPTNAME SALES OTHER FIELDS 1ALBERT 426.00 1BOZO 726.00 1CONNER 260.00 2AMATO4567.00 2BISHOP 634.00 3ALPHONSE 300.00 3COOK 500.00 3JASPER 395.00 3 MOTHER2496.00 4JOCKO 789.00 4JULIET 000.00 4NOVEMBER 100.00 4OSCAR2000.00 7ALPHA6299.00 7BRAVO7000.00 7COCOA 420.00 8DELTA.... 8FOXTROT 8GOLF 9ROMEO 9SIERRA 9TANGO 10EOF

26. 28 10-26 Minor Control Break Routine Print total for previous SlsNo-In Add salesperson total to department total Initialize salesperson total to zero Move new SlsNo-In to hold area

27. 28 10-27 Chapter Summary Control break program may have any number of control fields All input records must be in sequence by minor control fields within intermediate control fields within major control fields Sort file before processing if records are not already in this order

28. 28 10-28 Chapter Summary Control break routines –Higher-level breaks force lower-level breaks –Appropriate control total line printed –Appropriate control total is initialized –Appropriate control field is initialized