Store player informations with MySQL.

[ebusiangamers]

The problem is solved! Thanks IzNoGod!
Indeed all informations are uploaded/downloaded as string, I post the final version of the functions (that work):

		get_db_field(fieldname, vartype)
{
    if(isDefined(self.isbot))
        return undefined;
    
    if(fieldname == "user_guid")
        mysql_query(level.mysql_connection, "SELECT `"+fieldname+"` FROM `"+level.table+"` WHERE `user_name`= '"+self.name+"' LIMIT 1");
    else
        mysql_query(level.mysql_connection, "SELECT `"+fieldname+"` FROM `"+level.table+"` WHERE `user_guid`= '"+self.guid+"' LIMIT 1");
    r = mysql_store_result(level.mysql_connection);
    if(isdefined(r))
    {
        row = mysql_fetch_row(r);
        if(isdefined(row) && isdefined(row[0]))
        {
            mysql_free_result(r);
            if(vartype == "int")
                row[0] = (int)(row[0]);
            if(vartype == "float")
                row[0] = (float)(row[0]);
            return row[0];
        }
        mysql_free_result(r);
    }
    
    if(vartype == "int" || vartype == "float")
        return 0;
    else
        return undefined;

}  

set_db_field(fieldname, value) 
{
    if(isDefined(self.isBot))
        return;
    
    mysql_query(level.mysql_connection, "INSERT INTO `"+level.table+"`(`user_guid`, `"+fieldname+"`) VALUES ('"+self.guid+"', "+value+") ON DUPLICATE KEY UPDATE `"+fieldname+"`="+value+"");
    
    wait 0.05;
}

set_db_field_string(fieldname, value) 
{
    if(isDefined(self.isBot))
        return;
    
    mysql_query(level.mysql_connection, "INSERT INTO `"+level.table+"`(`user_guid`, `"+fieldname+"`) VALUES ('"+self.guid+"', '"+value+"') ON DUPLICATE KEY UPDATE `"+fieldname+"`='"+value+"'");
    wait 0.05;
} 
	

I want to learn to create something like CoDExtended or whatsoever, where should I start?