help with mysql_result

[elotherguy]

Hi, i know that this is a mysql question but i was hoping you guys would be able to help me!  This is the error I get:

 

Warning: mysql_result() [function.mysql-result]: Unable to jump to row 0 on MySQL result index 38 in /home/caritasd/public_html/am/libs/MySQL.class.php on line 118

 

 

  public function result($sql){

    if(!($res = mysql_query($sql, $this->link)))

      trigger_error("Error: Invalid query -> ".$sql."<br />MySQL said: ".mysql_error()."<br /><br />");

117    else

118      if(($return = mysql_result($res,0)))

119        return $return;

      else

        return false;

  }

[ShaunO]

Looks like your query isn't returning any rows.

[elotherguy]

know how i can get it to return a row?

[PFMaBiSmAd]

mysql_result, in addition to being the slowest way to get data from a result set is the only function that generates an error message when there are zero rows in the result set. You either need to test if there are any rows in the result set before using mysql_result or you need to use one of the mysql_fetch_xxxxx functions instead.

[elotherguy]

is the mysql_fetch_xx... functions pretty much interchangable?  sorry i'm very very new to this and am learning as fast as i can.

[ShaunO]

mysql_result, in addition to being the slowest way to get data from a result set is the only function that generates an error message when there are zero rows in the result set. You either need to test if there are any rows in the result set before using mysql_result or you need to use one of the mysql_fetch_xxxxx functions instead.

 

Shouldn't it be faster than mysql_fetch_xxxxx when returning a scalar result? (i.e a single column with a single row?)

[Andy-H]

Just add a condition like:

 

  public function result($sql){

    if(!($res = mysql_query($sql, $this->link)))

      trigger_error("Error: Invalid query -> ".$sql."

MySQL said: ".mysql_error()."

 

");

    else

 

$numrows = mysql_numrows($res);

 

if ($numrows == 0){

 

trigger_error("Error: Query -> ".$sql." returned 0 results.");

 

}else{

 

      if(($return = mysql_result($res,0)))

        return $return;

      else

        return false;

  }}

[elotherguy]

when i do that, this is the new error:

 

Notice: Error: Query -> SELECT `name` FROM `images` WHERE listing_id='ceebe6f4-ea9d-4757-8a1c-7bd08daf5ac5' ORDER BY `order` ASC LIMIT 1 returned 0 results. in /home/caritasd/public_html/am/libs/MySQL.class.php on line 122

 

[ShaunO]

What a pain in the ass that mysql_result throws a warning when it fails, considering it sets the value to false.

[elotherguy]

is there anyway to hide the errors??

[DarkWater]

Remove this line:

 

trigger_error("Error: Query -> ".$sql." returned 0 results.");

 

>_>

[PFMaBiSmAd]

Shouldn't it be faster than mysql_fetch_xxxxx when returning a scalar result? (i.e a single column with a single row?)

mysql_result() performs a data seek followed by a data read. The mysql_fetch_xxxxx functions just do a read at the current position.

[Andy-H]

oops lol

[elotherguy]

ok...one last question   so i'm trying to get information to be included in a contact email.  i.e. person's name/email based on when they registered...  however it doesn't inlcude it when i send the email.  Is this because of the previous error???

[PFMaBiSmAd]

Preventing that error from displaying does not change the fact that your query did not match any data in your database. You need to examine the data in your database and examine the query statement and determine why it did not match anything.

 

Your code should also not be continuing and sending an email where the query fails to find and return a matching row from your database (good programming practices.)