Any Questions!. Agenda Fun with Functions Externally Described Files Condition Names Iteration Logical Files Random Reads

Download Any Questions!. Agenda Fun with Functions Externally Described Files Condition Names Iteration Logical Files Random Reads

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Fun with Functions ILEFUNCT

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Any Questions! Agenda Fun with Functions Externally Described Files Condition Names Iteration Logical Files Random Reads Fun with Functions ILEFUNCT Condition Names Used with Code Fields Eg. ARE-THERE-MORE-RECORDS Eg. FINAL-GRADE Eg. Indicators Condition Names 01 ARE-THERE-MORE-RECORDS PIC X(3) VALUE YES. 88 THERE-ARE-MORE-RECORDS VALUE YES. 88 END-OF-FILEVALUE NO. IF THERE-ARE-MORE-RECORDS READ EMPLOYEE-FILE. IF END-OF-FILE PERFORM TERMINATION-RTN. Set Verb Used to initialize fields to a Condition- Name. 01 ARE-THERE-MORE-RECORDS PIC X(3). 88 THERE-ARE-MORE-RECORDS VALUE YES. 88 END-OF-FILEVALUE NO. SET END-OF-FILE TO TRUE. Conditions Contd 01 WORK-DAYS PIC X(3). 88 MONDAY VALUE MON. 88 TUESDAY VALUE TUE. 88 WEDNESDAY VALUE WED. 88 THURSDAY VALUE THU 88 FRIDAY VALUE FRI. SET MONDAY TO TRUE. IF FRIDAY DISPLAY GO HOME EARLY. Conditions Contd 01 FALL-MONTHS PIC X(3). 88 SEPTEMBER VALUE SEP. 88 OCTOBER VALUE OCT. 88 NOVEMBERVALUE NOV. 88 DECEMBER VALUE DEC. IF OCTOBER DISPLAY HAPPY HALLOWEEN!! SET DECEMBER TO TRUE. Option Indicators and Conditions 01 WS-indicators. 05 IN90 INDICATOR 90 PIC display-message value B1. 88 dont-display-message value B0. Set display-message to true. Set dont-display-message to true. If display-message If dont-display-message If not display-message Response Indicators and Conditions 01 WS-Control. 05 ws-function-key pic x(2). 88 F3 value 03 88 F12 value 12. 88 Enter value 00 05 ws-device-name pic x(10). 05 ws-record-format pic x(10). If F3 If not F3 Iteration Looping BASIC Perform Statement PERFORM (paragraph-name) Basic PERFORM READ Emp-File PERFORM DSP-Rtn STOP RUN DSP-RTN move emp-in to emp- out. write dsp-record format is SCREEN. read dsp-file record. PERFORM Until PERFORM paragraph-name UNTIL Condition PERFORM Until Condition Met? Execute Program Statements NO YES PERFORM Until READ Emp-File AT END Move YES TO EOF. PERFORM Dsp-Rtn UNTIL EOF = Y STOP RUN DSP-RTN move emp-in to emp-out. write dsp-record format is SCREEN. read dsp-file RECORD. read emp-file at end move YES to EOF. PERFORM X Times PERFORM (paragraph-name) THROUGH/THRU (paragraph-name) (integer/variable) TIMES PERFORM X Times Number of Times Met? Execute Program Statements NO YES PERFORM X Times READ Emp-File AT END Move YES TO EOF. PERFORM Dsp-Rtn 5 TIMES STOP RUN DSP-RTN move emp-in to emp- out. write dsp-record format is SCREEN. read dsp-file record. PERFORM With Test After PERFORM (paragraph-name) THROUGH/THRU (paragraph-name) WITH TEST AFTER UNTIL Condition PERFORM With Test After Condition Met? Execute Program Statements NO YES PERFORM With Test After READ Emp-File AT END Move YES TO EOF. PERFORM Dsp-Rtn WITH TEST AFTER UNTIL EOF = Y STOP RUN DSP-RTN move emp-in to emp-out. write dsp-record format is SCREEN. read dsp-file record. read emp-file AT END MOVE YES TO EOF. PERFORMs within PERFORMs READ Emp-File AT END Move YES TO EOF. PERFORM DSP-Rtn UNTIL 5 TIMES STOP RUN DSP-RTN MOVE EMP-IN TO EMP-OUT. PERFORM Write-Rtn Iteration Statement to Use? Perform Until Tests for the condition first Statements are executed only if the condition is true Perform With Test After tests for the condition last Statements are always executed at least once Iteration Statement to Use? Perform X Times Use this when you know the number of times the paragraph(s) are to be executed. Sorting Data Using Access Paths Physical Files vs Logical Files EMPLOYEEPF *FILE EMPLOYEE *FILE Physical Files or Logical Files? Externally Described Files Select Statement when physical/logical file has a key. SELECT Cobol-file-name ASSIGN TO database-actual-file-name [ORGANIZATION IS INDEXED] [ACCESS MODE IS SEQUENTIAL] RECORD KEY is data-element. (data-element could be EXTERNaLLY-DESCRIBED-KEY) Externally Described Files Copying the record layout. FD Cobol-file-name. 01 Cobol-Record-Name. COPY DD-actualrecordname OF actualfilename. (DD can be replaced by DDS if you require the 10 char field names instead of the aliases) Handy Physical File Commands DSPPFM Display Physical File Member Displays the contents of a Physical File in arrival sequence. DSPFD Display File Description Information about the file eg access path. DSPFFD Display File Field Description Displays the fields in the file. Random Reads Used to retrieve a record based on the value of a key field Need an access path sorted by the key field needed Select statement changes Defining a Random Access File SELECT Employee-File ASSIGN to DATABASE-EMPPF ORGANIZATION is INDEXED ACCESS MODE is RANDOM RECORD KEY is EXTERNALLY-DESCRIBED-KEY (with duplicates). Random Reads If the key field to EMPPF is the Employee- Number then: Move 1 to Employee-Number. Read Employee-File Invalid Key Move Error to Employee-Name-Out Not invalid key Move Employee-Name to Employee-Name- out End-Read. Validating the Province Code Database object: PROVINCES