ODBC Error Handling

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Revision as of 10:14, 29 May 2009

ODBC Error Handling

Error Generation

When using the CONTROL function, error information (if any) will be contained in the returned <Result> string.

When an Internal or ODBC error occurs during a Read or Write operation, the error information must be obtained from the driver using the dbGetLastError command.

Example:

   Write (Lun, RSDefinition) Excp = BadDefinition
   .
   .
   Return
   .
   BadDefinition:
       Result$ = Control(Lun, "dbGetLastError")
       Print Result$
       Goto Abort
   .
   Error Interpretation

Internal errors generated by the Comet ODBC driver are returned in the form of:-
“Local:<Type><ErrorNum> <ErrorDescription>”
where:

“Local:” Indicates an internal driver error. <Type>

“D” if the error occurred during a Database command.
“R” if the error occurred during a Recordset command.

<ErrorNum> One of the following errors:

Database Errors:

DBERR.NONE		//  0-No error
DBERR.CMDINVALID	//  1-Invalid command
DBERR.SYSTEM		//  2-Non CDatabase thrown exception
DBERR.ODBC		//  3-CDatabase thrown exception
DBERR.FUNCTION		//  4-Function failed (BOOL)
DBERR.INVPARAM		//  5-Invalid command parameter
DBERR.RSINVALID        //  6-Invalid or unknown recordset
DBERR_NOTOPEN          //  7 - Database is not open

Recordset Errors:

RSERR.NONE		//  0-No error
RSERR.CMDINVALID	//  1-Invalid command
RSERR.SYSTEM		//  2-Non CRecordset thrown exception
RSERR.ODBC		//  3-CRecordset thrown exception
RSERR.FUNCTION		//  4-Function failed
RSERR.INVPARAM		//  5-Invalid command parameter
RSERR.INVTYPE		//  6-Incorrect Internet Basic type for SQL type
RSERR.TYPENOSUP	//  7-SQL type not supported
RSERR.INVWRITE		//  8-Unexpected write
RSERR.EOF		//  9-End of File
RSERR.INVBOOKMARK	// 10-Invalid bookmark
RSERR.EXPWRITE		// 11-Write was expected
RSERR.INVCOLUMN        // 12-Bind Column not found
RSERR.DATAERROR        // 13-Loss of data would occur
RSERR_INVMAP		// 14-Invalid item in map
RSERR_NOTOPEN		// 15-Recordset is not open

Errors returned by the ODBC driver are returned in the following forms:

If the “ErrorCodes” option was NOT specified when the Database object was created the error string will be in the form of a use decipherable message.

If the “ErrorCodes” option was specified when the Database object was created the error string will be:

State:<strState>,Native:<nNative>,Origin:<strErrorMsg>

<strState> A five-character error code returned in the szSqlState parameter <nNative> The native error code, specific to the data source. <strErrorMsg > The error message text returned in the szErrorMsg parameter of the ::SQLError function.
This message consists of several bracketed names.
As an error is passed from its source to the user, each ODBC component (data source, driver, Driver Manager) appends its own name.
This information helps to pinpoint the origin of the error.