No Output from a MySQL Join

whartman

Here is what I am trying to do. I have two tables, Member and MemberTemp. I want to select all the information from Member usernames that do not exist in MemberTemp. I wrote the following code to do this:

$query = "SELECT * FROM Member LEFT JOIN MemberTemp
ON Member.username=MemberTemp.username
WHERE MemberTemp.username IS NULL";
$result = mysql_query($query);
$num_rows = mysql_num_rows($result);
echo $num_rows;
while ($row = mysql_fetch_array($result,MYSQL_ASSOC))
{
extract($row);
echo $username;
}

$num_rows outputs the correct number of rows, but I receive absolutely no output from the $username variable. I don't know why I cannot access any of the variables in $row.

Can you help me? Is my query or my php wrong?

THANK YOU FOR YOUR HELP. I'VE BEEN STUCK FOR A LONG TIME.

LordShryku

For debugging, instead of doing this

extract($row);
echo $username;

Do this

echo "<pre>";
print_r($row);
echo "</pre>";

Then you'll see the variable names.

whartman

Thanks for the tip. That helped me solve the first problem. Now I have another one that leaves me similarly confused. I have this query:

$login_query = "SELECT MAX(Login.login_time) FROM Login WHERE Login.username = $username";

$login_result = mysql_query($login_query)

or die("login query failed - ".mysql_error());

When I run the code, I get this error:
login query failed - Unknown column 'bonfire68' in 'where clause'

I've checked that all of my column and table names are correct. By the way, the username in $username = bonfire68. Why does it think that this is a column name?

THANK YOU SO MUCH!

Roger_Ramjet

Its because you have omitted the string quotes from around the variable, so MySQL is reading it as a column name not a string value.

$login_query = "SELECT MAX(Login.login_time) FROM Login WHERE Login.username = '$username' ";