ODBC错误处理

/* Declare required variables */
SQLHDBC dbc;
SQLHSTMT stmt;
SQLRETURN retcode;
UCHAR errmsg[100];
/* Code omitted here */
retcode = SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt ); 
if( retcode == SQL_ERROR ){
   SQLError( env, dbc, SQL_NULL_HSTMT, NULL, NULL,
         errmsg, sizeof(errmsg), NULL );
   /* Assume that print_error is defined */
   print_error( "Allocation failed", errmsg );
   return;
}

/* Delete items for order 2015 */
retcode = SQLExecDirect( stmt,
       "DELETE FROM SalesOrderItems WHERE ID=2015",
       SQL_NTS ); 
if( retcode == SQL_ERROR ) {
   SQLError( env, dbc, stmt, NULL, NULL,
            errmsg, sizeof(errmsg), NULL );
   /* Assume that print_error is defined */
   print_error( "Failed to delete items", errmsg );
   return;
}

/* Declare required variables */
SQLHDBC dbc;
SQLHSTMT stmt;
SQLRETURN retcode;
SQLSMALLINT errmsglen;
SQLINTEGER errnative;
UCHAR errmsg[255];
UCHAR errstate[5]; 
/* Code omitted here */
retcode = SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt );
if( retcode == SQL_ERROR ){
   SQLGetDiagRec(SQL_HANDLE_DBC, dbc, 1, errstate,
       &errnative, errmsg, sizeof(errmsg), &errmsglen);
    /* Assume that print_error is defined */
   print_error( "Allocation failed", 
errstate, errnative, errmsg );
   return;

}
/* Delete items for order 2015 */
retcode = SQLExecDirect( stmt,
       "DELETE FROM SalesOrderItems WHERE ID=2015",
       SQL_NTS ); 
if( retcode == SQL_ERROR ) {
   SQLGetDiagRec(SQL_HANDLE_STMT, stmt, 
       recnum, errstate,
       &errnative, errmsg, sizeof(errmsg), &errmsglen);
   /* Assume that print_error is defined */
   print_error("Failed to delete items", 
       errstate, errnative, errmsg );
   return;
}