Question

I have the following code in php:

<?php
$con = mysql_connect("localhost","john","john");

mysql_select_db("data", $con);
if (!$mysql_select_db) {
    die ('Cannot use data : ' . mysql_error());
}

$result = mysql_query("SELECT * FROM test where huss='hussein'");

while ($row = mysql_fetch_array($result)) {
    echo "ADSDAD";
    echo "<br />";
}

if (!$con) {
    die('ERROR Could not connect: ' . mysql_error());
}

mysql_close($con);
?>

I was able to connect to the MySQL server, but I can’t seem to select the relevant database.

Being printed is the hard-coded text Cannot use data :, but no MySQL error message follows it. If the MySQL connection had failed then I would have expected a MySQL error message to appear after the hard-coded text.

What am I doing wrong?

Answer 1

The problem’s here:

mysql_select_db("data", $con);
if (!$mysql_select_db) {
    die ('Cannot use data : ' . mysql_error());
}

You don’t have a variable $mysql_select_db, and it doesn’t magically map to the result of the last time you called mysql_select_db.

So, instead:

$result = mysql_select_db("data", $con);
if (!$result) {
    die ('Cannot use data : ' . mysql_error());
}

Or:

if (!mysql_select_db("data", $con)) {
    die ('Cannot use data : ' . mysql_error());
}