Capturing SQL Error Messages
From InterBase
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Use isc_sql_interprete() to build a SQL error message based on a specific SQL error code and store it in a buffer defined by an application. Capturing messages in a buffer is useful when applications:
- Run under windowing systems that do not permit direct screen writes.
- Store a record of all error messages in a log file.
- Manipulate or format error messages for display or pass them to a windowing system’s display routines.
isc_sql_interprete() requires three parameters: a valid SQL error code, usually passed as a variable named SQLCODE, a buffer where the SQL message should be stored, and the size of the buffer. The following code illustrates how this function might be called to build a message string and store it in a log file:
#include <ibase.h>
. . .
ISC_STATUS status_vector[20];
isc_tr_handle trans;
long SQLCODE;
char msg[512];
FILE *efile; /* Code fragment assumes pointer to an open file. */
trans = 0L;
. . .
/* Assume a transaction, trans, is started here. */
/* Assume an API call returning status information is called here. */
. . .
/* Error-handling routine starts here. */
if (status_vector[0] == 1 && status_vector[1] > 0) {
SQLCODE = isc_sqlcode(status_vector);
isc_sql_interprete(SQLCODE, msg, 512);
fprintf(efile, "%s\n", msg);
isc_rollback_transaction(status_vector, &trans);
return(1);
}
Note:
This code fragment assumes that the log file is properly declared and opened elsewhere in the application before control is passed to this error handler.
This code fragment assumes that the log file is properly declared and opened elsewhere in the application before control is passed to this error handler.