CODEWITHSUNDEEP
phpmysql
mintuz
mintuz

Reputation: 721

PHP Mysql If statement not working

Got a issue where if the rows are equal to 0 the else statement is not called. if i type in the correct details on the site, the first condition is met and the xml is displayed, however if the incorrect details are entered, the error xml is not displayed.

echo "<users>"; 
$result = mysql_query("SELECT * FROM `numbers` WHERE `email` = '".$email."' AND `password` = '".$password."'") or die('Invalid query: ' . mysql_error());

if (!$result) die('Invalid query: ' . mysql_error());
while ($row = mysql_fetch_array($result, MYSQL_ASSOC))
{
    if(mysql_num_rows($result) != 0)
    {
        echo "<usercallback>";
        echo  "<id>".$row['id']."</id>";
        //echo  "<number>".$row2['number']."</number>";
        //echo  "<gender>".$row2['gender']."</gender>";
        //echo  "<relationship>".$row2['relationship']."</relationship>";
        echo  "</usercallback>";
    }
    else
    {
        echo "<usercallback>";
        echo  "<id>error</id>";
        echo  "</usercallback>";
    }
}

echo "</users>";

Upvotes: 2

Views: 510

Answers (4)

Mithun Satheesh
Mithun Satheesh

Reputation: 27845

actually you have to put the if mysql_num_rows check outside the while block 

echo "<users>"; 
$result = mysql_query("SELECT * FROM `numbers` WHERE `email` = '".$email."' AND `password` = '".$password."'") or die('Invalid query: ' . mysql_error());


if(mysql_num_rows($result) != 0)
    {
    while ($row = mysql_fetch_array($result, MYSQL_ASSOC))
        {       
        echo "<usercallback>";
        echo  "<id>".$row['id']."</id>";
        //echo  "<number>".$row2['number']."</number>";
        //echo  "<gender>".$row2['gender']."</gender>";
        //echo  "<relationship>".$row2['relationship']."</relationship>";
        echo  "</usercallback>";
        }
    }
    else
    {
        echo "<usercallback>";
        echo  "<id>error</id>";
        echo  "</usercallback>";
    }

echo "</users>";

Upvotes: 6

Dan Ray
Dan Ray

Reputation: 21893

It looks like you're expecting a zero-row response from MySQL to result in an undef $result. That's not what happens. mysql_query() returns null if there was an error. You can test the "truth" of its return value to see if the query ran correctly. If the query results in 0 rows of response, it ran correctly. The value to test, then is mysql_num_rows($result).

However, it can be done simpler. I usually write this like:

$res = mysql_query("SELECT 1");
if (!$res) {
    //do whatever error reporting if the SQL was bad
    //though you should probably deal with any condition that ends up
    //here before you go into production!
}
if (mysql_num_rows($res) == 0) {
    //put out my "no results found" message
}
while ($row = mysql_fetch_assoc($res)) {
    //do my per-row business
}

mysql_fetch_assoc() returns false when there are no (or no more) results to return. So if it's empty, that while loop will never run, so it doesn't need to be inside an else.

Upvotes: 0

user908378
user908378

Reputation:

You check for rows while performing the loop, you should check for the number of rows BEFORE the while loop.

Upvotes: 0

Pradeep
Pradeep

Reputation: 1254

while ($row = mysql_fetch_array($result, MYSQL_ASSOC))

If there are no rows then $row will be false and it will never enter the above while loop. So you can not get error message

Upvotes: 0

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