Dclgen

A declarations generator or DCLGEN (pronounced dekel-jin) is a table schema used by COBOL programs that work against a database, often IBM DB2 on a mainframe.

Composition

A DCLGEN generally has two sections: The SQL declaration for a DB2 table and the COBOL COPYBOOK definition corresponding to the SQL declaration.

Example

     ******************************************************************        
     * DCLGEN TABLE(STUDENTS)                                         *                     
     *        LIBRARY(DEVL.SAP.STUDENTS(STUDENTS))                    *        
     *        ACTION(REPLACE)                                         *        
     *        LANGUAGE(COBOL)                                         *        
     *        NAMES(SAP-)                                             *        
     *        APOST                                                   *        
     *        COLSUFFIX(YES)                                          *        
     ******************************************************************        
          EXEC SQL DECLARE STUDENTS TABLE                               
          ( ID                             DECIMAL(11, 0) NOT NULL,            
            STUDENT_NUM                    SMALLINT NOT NULL,                  
            ACTIVE                         CHAR(1) NOT NULL,                   
            REG_TIME                       TIMESTAMP NOT NULL,                 
            START_DATE                     DATE NOT NULL,                      
            END_DATE                       DATE NOT NULL                      
           ) END-EXEC.                                                          
     ******************************************************************        
     * COBOL DECLARATION FOR TABLE STUDENTS                           *        
     ******************************************************************        
      01  DCLABNV-GST-STATUS.                                                  
          10 ID                   PIC S9(11)V USAGE COMP-3.                    
          10 STUDENT-NUM          PIC S9(4) USAGE COMP.                        
          10 ACTIVE               PIC X(1).                                    
          10 REG-TIME             PIC X(26).                                   
          10 START-DATE           PIC X(10).                                   
          10 END-DATE             PIC X(10).                                   
     ******************************************************************        
     ******************************************************************               

Usage

DCLGEN libraries are specified as input for the PDL program. This is used to pre-generate Delta virtual macros, and as input for PDL for generating Delta code, and is also used by the DB2 pre-compiler ( normally DSNHPC, but in the case of compiling with Viasoft the compiler is VIASQL.

DCLGENs must be pre-compiled (for use with via Delta Virtual Macros, Delta, or DB2) before the source can be compiled as COBOL (using IGYCRCTL normally, or using VIACOBII for Viasoft SmartTest).

References

• Baker, Bonnie (October 2003). "Say What? - Plans + DBRMS + Packages + Collections + Versions = Confusion". TOP500. http://www.ibmdatabasemag.com/showArticle.jhtml?articleID=15300107. Retrieved 2008-03-04.