Module 14:- Database Interface
- SQLCA stands for SQL Communication Area and it is DB2 system provided copybook.
- SQLCA has multiple Host variables defined to hold the information about last executed SQL statement
- All host variables gets updated after the execution of each SQL statement.
- Thus, every COBOL program containing Embedded SQL statements must have SQLCA included in WORKING-STORAGE SECTION.
DATA DIVISION. WORKING-STORAGE SECTION. EXEC SQL INCLUDE SQLCA END-EXEC.
- This copybook provide capability to COBOL program to check whether last query execution was successful or not. This can be done by examining the value contained in SQLCODE host variable.
- SQLCODE = ‘000’ indicates successful execution of last SQL statement.
- There is one more important host variable “SQLERRD(3)” which is used to hold number of rows affected by last SQL statement
- Information held by SQLCA host variable enable us to: -
- Debug our code. Using debugger, one can view the SQLCA fields and examine its error codes and warning flags. We can also display SQLCA fields value in SYSOUT to debug.
- Control flow of our program by testing its values. For example, if SQLCODE indicates error, we can call error-processing paragraph.