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DBMS-Based Driver Diagnostic Example

  • Artikkeli

A DBMS-based driver sends requests to a DBMS and returns information to the application through the Driver Manager. Because the driver is the component that interfaces with the Driver Manager, it formats and returns arguments for SQLGetDiagRec.

For example, if, using SQL/Services, a Microsoft driver for Oracle Rdb encountered an invalid cursor name, it might return the following values from SQLGetDiagRec:

SQLSTATE:         "34000"  
Native Error:      0  
Diagnostic Msg:   "[Microsoft][ODBC Rdb Driver]Invalid cursor name: EMPLOYEE_CURSOR."

Because the error occurred in the driver, it added prefixes to the diagnostic message for the vendor ([Microsoft]) and the driver ([ODBC Rdb Driver]).

If the DBMS could not find the table EMPLOYEE, the driver might format and return the following values from SQLGetDiagRec:

SQLSTATE:         "42S02"  
Native Error:      -1  
Diagnostic Msg:   "[Microsoft][ODBC Rdb Driver][Rdb] %SQL-F-RELNOTDEF, Table EMPLOYEE "  
                  "is not defined in schema."

Because the error occurred in the data source, the driver added a prefix for the data source identifier ([Rdb]) to the diagnostic message. Because the driver was the component that interfaced with the data source, it added prefixes for its vendor ([Microsoft]) and identifier ([ODBC Rdb Driver]) to the diagnostic message.