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Looking for an efficient way to verify the existance of an account - Printable Version

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+--- Thread: Looking for an efficient way to verify the existance of an account (/showthread.php?tid=655001)


Looking for an efficient way to verify the existance of an account - Robin96 - 11.06.2018

Hi all,

I am working on a command that allows admins to offline ban an account. In order to do that I must verify whether or not the account actually exists in the database. Currently my disfunctional code is this:

This if-statement is in the offline ban command:

PHP код:
if(!DoesAccountExist(player))
        {
            SendClientMessage(playerid, COLOR_RED, "This account does not exist.");
        } 
And this is the code of DoesAccountExist:
PHP код:
DoesAccountExist(name[])
{
    new query[75];
    format(query, sizeof(query), "SELECT * FROM player WHERE name = '%s' LIMIT 1", EscapeString(name));
    return mysql_tquery(sql_connection, query, "OnDoesAccountExist");
}
forward OnDoesAccountExist();
public OnDoesAccountExist()
{
    new row_count;
    cache_get_row_count(row_count);
    if(!row_count) return 0;
    else return 1;
} 
This obviously does not work because mysql_tquery returns 1 or 0 depending on whether or not the query was executed succesfully, rather than what information it retrieved from the query.

What's the most efficient way to get what I am trying to get? Which is returning a 1 or 0 depending on if a Select statement returned any rows.

Re: Looking for an efficient way to verify the existance of an account - SyS - 11.06.2018

You can send update query and check the affected rows count

PHP код:
/*Inside your ban command */
new query[75]; 
mysql_format(sql_connection, sizeof(query), "UPDATE player SET BANNED = 1 WHERE name = '%e'", name); //change the query according to your table structure 
mysql_tquery(sql_connection, query, "OnBanPlayer","d", playerid); //Playerid of player who executed command is passed to callback so as to send client message 
Then in the call back
PHP код:
forward OnBanPlayer(whomexecuted); 
public OnBanPlayer(whomexecuted) 
{ 
    
    if(!cache_affected_rows()) return SendClientMessage(whomexecuted, COLOR_RED, "This account does not exist."); 
    else
    { 
        /*Ban the player...*/
        SendClientMessage(whomexecuted, COLOR_RED, "Banned player successfully.."); 
        return 1;
    } 
} 


Re: Looking for an efficient way to verify the existance of an account - Gammix - 11.06.2018

You can try this SQL statement, which is proven to be faster than COUNT(*).

PHP код:
SELECT EXISTS(SELECT 1 FROM player WHERE  name = '%e' LIMIT 1) 
Also, you don't need "EscapeString", mysql_format has a custom specifier for escaping strings with '%e'.

Re: Looking for an efficient way to verify the existance of an account - Kane - 11.06.2018

A non threaded query for what you're trying to achieve. SyS's method may be better though.

Re: Looking for an efficient way to verify the existance of an account - Robin96 - 11.06.2018

Thank you! I am going to handle it that way.

Is there any way to get data out of the row that was affected by the UPDATE statement? In this particular case I am trying to do the following:

- Admin uses command to offline ban a player
- Update statement to be executed, if succesful the player is banned
- IP address and primary key of the affected player should be retrieved
- The IP address and primary key is to be used in 2 additional INSERT statements


Can I fetch the data of the affected row or should I execute a new SELECT statement?