Specifying a CCSID for your application

In Db2 for z/OS® applications, one CCSID is associated with the source code and one or more CCSIDs can be associated with the data that your application manipulates. The CCSID that Db2 associates with the data is called the application encoding scheme.

To specify a CCSID for your application, use the following approaches:

1. Use the options as shown in the following table:

   Table 1. Options to set application CCSIDs

   Item for which you want to specify the CCSID	Option to use
   Application source code (which includes SQL statements and literal strings in the SQL statements)	If you are using the Db2 precompiler, use the CCSID SQL processing option when you precompile the application. Specify the same CCSID when you compile the application. If you are using the Db2 coprocessor, use the language compiler to set the CCSID. For COBOL, PL/I, and C/C++, use the following instructions1: Specifying CCSIDs for COBOL applications when using the Db2 coprocessor Specifying CCSIDs for PL/I applications when using the Db2 coprocessor Specifying CCSIDs for C/C++ applications when using the Db2 coprocessor The default CCSID for the application source code is the subsystem EBCDIC CCSID (DECP value SCCSID or MCCSID). Db2 uses this value if you do not use one of the preceding mechanisms to specify a CCSID. Restriction: The compilers for high level host languages do not support Unicode source code.
   Application data (values that are passed through host variables and parameter markers) within SQL statements2	You can use one or more of the following Db2 approaches to specify CCSID values for the application data3, which is called the application encoding scheme: Use the ENCODING bind option.4 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). The default CCSID for the application data is the subsystem default application encoding scheme. For static SQL (host variables), this value is the APPENSCH value from the DECP that is loaded when you bind your application. For dynamic SQL (parameter markers), this value is the APPENSCH value from the DECP that is loaded at the time that the application is executed. Alternatively, if you are using the Db2 coprocessor for COBOL or PL/I applications, you can override the ENCODING bind option by using language-specific compiler options. For more information, see the following topics: Specifying CCSIDs for COBOL applications when using the Db2 coprocessor Specifying CCSIDs for PL/I applications when using the Db2 coprocessor
   Application data that is referenced outside of SQL statements	Use the rules of the programming language. In some cases, the CCSID of this data is the same as the CCSID of the source code.

2. Optional: If you want to confirm which CCSID value the Db2 precompiler used, look at the precompiler listing. If you want to confirm which CCSID value the Db2 coprocessor used, look at the compiler listing.
   If you need help finding the CCSID values in these listings, see the example listings in Finding the CCSID values of your data sources.

   You can also use these listings to confirm which DECP module Db2 used. Knowing which DECP module is useful if you modified a DECP value, such as APPENSCH, before you compiled or executed your program. You can see which DECP module and which values Db2 used.