Preprocessing of Dynamic Queries with C or Pascal Routines

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   WORKING-STORAGE SECTION.

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   DYNAMIC-CMD contains the SQL command to be executed by the subprogram.



   01  {{DYNAMIC-CMD}}            PIC X(1014).



   SQLCA is the data structure that contains current information about a program's DBE session.



   EXEC SQL INCLUDE {{SQLCA}} END-EXEC.

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   PROCEDURE DIVISION.

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   Connect to the DBEnvironment.

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   Load DYNAMIC-CMD with the SQL command to be executed.

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   {{CALL "performcommand" USING DYNAMIC-CMD,}}

                               {{SQLCA.}}

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   Global variable declarations needed by the C routines for dynamic preprocessing:



   EXEC SQL BEGIN DECLARE SECTION;

   char          {{DynamicCommand[1014]}};

   EXEC SQL END DECLARE SECTION;



   EXEC SQL INCLUDE {{SQLCA}};



   EXEC SQL INCLUDE {{SQLDA}};

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   {{performcommand (dynamicparm, sqlcaparm)}}



   The COBOL program has passed the parameters to performcommand by reference, so

   the formal parameters are declared here as addresses.



   char  {{dynamicparm[]}};

   char  {{sqlcaparm[]}};



   {



   int  k;

   char *destptr;

   char *sourceptr;



   DynamicCommand must be declared as host variable in this subprogram.  Copy the

   formal parameter into the host variable.



   for (k = 0; k < sizeof(DynamicCommand); k++ )

       DynamicCommand[k] = dynamicparm[k];



   The sqlcaparm passed to this subprogram is an address pointing to the SQLCA 

   area of the calling program, and the SQLCA used by this subprogram is a global  

   variable.  Since the formal parameters in performcommand cannot be global  

   (i.e.-- extern), copy the sqlcaparm parameter to the SQLCA. 



   Use pointers (addresses) to copy the sqlcaparm to SQLCA because the SQLCA is

   a structure.  Sourceptr is set to sqlcaparm, the address of the SQLCA passed to 

   the subprogram. 



   Destptr is assigned the address of the SQLCA used by this subprogram.  Then, 

   assign the contents of the sourceptr to the contents of the destptr and increment 

   the values of both pointers until the entire sqlcaparm has been copied. 



   sourceptr = sqlcaparm;

   destptr   = &sqlca;



   for (k = 1; k <= sizeof(sqlca); k++) {

      *destptr = *sourceptr;

      sourceptr;

      destptr;

      }



   Issue the SQL PREPARE and DESCRIBE commands.  Parse the data buffer and  

   display the rows fetched by the query.  See the cex10a program in the ALLBASE/SQL 

   C Application Programming Guide for more information. 



   Before returning to the COBOL program copy SQLCA to sqlcaparm.  This permits 

   the COBOL program to access the information in the SQLCA.



   sourceptr = &sqlca;

   destptr   = sqlcaparm;



   for (k = 1; k <= sizeof(sqlca); k++) {

      *destptr = *sourceptr;

      sourceptr++;

      destptr++;

      }

   }   /* End of performcommand */

   Type

      Dynamic_Type = Packed Array [1..1014] of char;

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   Global variable declarations needed by the Pascal routines for dynamic

   preprocessing:



   EXEC SQL BEGIN DECLARE SECTION;

   {{DynamicCommand}} : Packed Array [1..1014] of char;

   EXEC SQL END DECLARE SECTION;



   EXEC SQL INCLUDE {{SQLDA}};

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   Procedure PerformCommand (Var {{DynamicParm}}    : Dynamic_Type;

                             Var {{SQLCA}}          : SQLCA_Type);

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   Begin  (* Procedure PerformCommand *)



   Because the outer block is a non-Pascal program, the stdlist and stdin must be

   opened explicitly.



   Rewrite (output,'$stdlist');

   Reset   (input, '$stdin','shared');



   DynamicCommand must be declared as a host variable in the Pascal subprogram. 

   Copy the DynamicParm parameter to the DynamicCommand host variable before

   proceeding.



   DynamicCommand := '';

   strmove (1014,DynamicParm,1,DynamicCommand,1);



   Issue the SQL PREPARE and DESCRIBE commands.  Parse the data buffer and

   display the rows fetched by the query.  See the pasex10a program in the

   ALLBASE/SQL Pascal Application Programming Guide for more information.



   End; (* Procedure PerformCommand *)