Application Progamming(COBOL+DB2)

DCLGEN :

   Declaration Generator .  a tool to generates the equivalent COBOL variables.

   Which can be used to generate host variables with equivalent data types of DB2 columns.

Host variables:

Ø  Can be used to pass the data from cobol program to DB2 table or DB2 table to COBOL program.

Ø  When host variables are coded with sql statements it must be prefixed with : like :hv-cname.

Ø  Table name must be supplied as input to DCLGEN & partition dataset should be as output.

Ø  After creating DCLGEN variables which must be copied to application program in WORKING-STORAGE SECTION  by using include command i.e.

Exec sql

   Inlcude custDCL

End-exec.

Ø  Include & copy have the same functionality

SQLCODE :

Ø  Predefined numeric number which can be used to check SQL statements for successful , unsuccessful execution.

Ø  SQLCODE can be stored in SQLCA(SQL Communication Area)

Ø  Copy SQLCA in WORKING-STORAGE SECTION

Ø  System defined variable

Ø  Evaluate or if statement must be coded to check the SQLCODE immediately after SQL statement.

Ø  SQLCODE =00 ---- successful

                          = +100 --- end of table or record not found.

Sample program:

WORKING-STORAGE SECTION.

            EXEC SQL

                        INCLUDE SQLCA

            END-EXEC

            EXEC SQL

                         INCLUDE CUSTDCL

            END-EXEC.

01 WS-SQL-CODE PIC S9(4)

            88 88-SUCCESS VALUE 00

            88 88-NOTFOUND VALUE 100

            88 88-FORIENG KEY VOILATION VALUE –532

            88 88- MULITPLE ROW VALUE –811

PROCEDURE DIVISION.

            UPDATE CUST

                        SET CNAME = :HV-CNAME

            WHERE CNO=:HV-CNO

            MOVE SQLCODE TO WS-SQLCODE.

            EVALUE WS-SQL-CODE

                        WHEN 88-SUCCESS

                                    DISPLAY “SUCCESSFULLY UPDATED”

                        WHEN 88-NOTFOUND

                                    DISPLAY “ RECORD NOT FOUND”

                        WHEN 88-FOREIGNKEYVOILATION

                                    DISPLAY “ FOREIGN KEY VOILATION”

                        WHEN OTHER

                                    DISPLAY “ ERROR OCCURRED IN UPDATE”

                                    STOP RUN

            END-EVALUATE.

            STOP RUN.