Specifying CCSIDs for C/C++ applications when using the Db2 coprocessor

If you use the Db2 coprocessor to prepare a C/C++ application with SQL statements, use the C/C++ compiler to specify the CCSID of the application source. Use Db2 mechanisms to specify the CCSID of the application data that is manipulated in SQL statements.

To specify CCSIDs for C/C++ applications when using the Db2 coprocessor:

1. Specify the CCSID for the source code by specifying a LOCALE value.
   For example, the following JCL EXEC statements for C compile jobs specify a CCSID of 1047. The first statement specifies a LOCALE for U.S. applications. The second statement specifies a LOCALE for German applications.

   //C EXEC PGM=CCNDRVR,PARM='SQL(),SO,LIST,LOCALE(En_US.IBM-1047)'
   

   //C EXEC PGM=CCNDRVR,PARM='SQL(),SO,LIST,LOCALE(De_CH.IBM-1047)'
   

   Alternatively, you can use other more advanced methods to specify the CCSID of the source code and any data that is outside of SQL statements. For more information about those methods, see the internationalization information in the C/C++ Programming Guide.

   Otherwise, if you do not specify a CCSID to the C/C++ compiler, the default C/C++ LOCALE of 1047 is passed to the Db2 coprocessor.

   For examples, the following JCL EXEC statements for a C compile job does not specify a LOCALE value. Therefore, the default value of 1047 is passed to the Db2 coprocessor.

   //C EXEC PGM=CCNDRVR,PARM='SQL()'

   Recommendation: If you are using the Db2 coprocessor on a C/C++ application, do not specify the SQL compiler option with the CCSID suboption. If you specify it anyway, and it conflicts with the LOCALE value, Db2 issues a warning. For example, the following EXEC statement for a C compile job specifies a CCSID value of 1047; the CCSID value 37 is ignored:

   //C EXEC PGM=CCNDRVR,PARM='SQL(CCSID(37)),LOCALE(De_CH.IBM-1047)'
   

2. Optional: You can specify different encoding schemes for application data that the program processes. You can use one or more of the following Db2 approaches to specify CCSID values for the application data¹, which is called the application encoding scheme:
   • Use the ENCODING bind option.² This option typically yields the best performance.
   • You can override the CCSID for a particular host variable by using the DECLARE VARIABLE statement with the CCSID option.
   • You can override the CCSID for parameter markers in dynamic SQL by specifying the CURRENT APPLICATION ENCODING SCHEME special register. Db2 uses the value of this special register at the time that the statement is executed.
   • If you use an SQL descriptor to define application data the previous options in this list might not apply if CCSID overrides are defined for host variables and parameter markers in the SQL descriptor (SQLDA).