Object-oriented extensions in COBOL

When you use object-oriented extensions in a COBOL application, you need to consider where to place SQL statements, the SQLCA, the SQLDA, and host variable declarations. You also need to consider the rules for host variables.

Where to place SQL statements in your application: A COBOL source data set or member can contain the following elements:

Multiple programs
Multiple class definitions, each of which contains multiple methods

You can put SQL statements in only the first program or class in the source data set or member. However, you can put SQL statements in multiple methods within a class. If an application consists of multiple data sets or members, each of the data sets or members can contain SQL statements.

Where to place the SQLCA, SQLDA, and host variable declarations: You can put the SQLCA, SQLDA, and SQL host variable declarations in the WORKING-STORAGE SECTION of a program, class, or method. An SQLCA or SQLDA in a class WORKING-STORAGE SECTION is global for all the methods of the class. An SQLCA or SQLDA in a method WORKING-STORAGE SECTION is local to that method only.

If a class and a method within the class both contain an SQLCA or SQLDA, the method uses the SQLCA or SQLDA that is local.

Rules for host variables: You can declare COBOL variables that are used as host variables in the WORKING-STORAGE SECTION or LINKAGE-SECTION of a program, class, or method. You can also declare host variables in the LOCAL-STORAGE SECTION of a method. The scope of a host variable is the method, class, or program within which it is defined.