13-1.txt

《linux应用开发技术详解》的配套代码

MYSQL_RES *result;
unsigned int num_fields;
unsigned int num_rows;
if (mysql_query(&mysql,query_string)){
    		// error
}
else // query succeeded, process any data returned by it
{
    	result = mysql_store_result(&mysql);
    	if (result)  // there are rows
    	{
        	num_fields = mysql_num_fields(result);
        	// retrieve rows, then call mysql_free_result(result)
    	}
    	else  // mysql_store_result() returned nothing; should it have?
    	{
        	if(mysql_field_count(&mysql) == 0)
        	{
            	// query does not return data
            	// (it was not a SELECT)
           		 num_rows = mysql_affected_rows(&mysql);
        	}
        	else // mysql_store_result() should have returned data
        	{
            	fprintf(stderr, "Error: %s\n", mysql_error(&mysql));
        	}
    	}
}