Object can't be converted to a string in MySQLi PHP

Question

Catchable fatal error: Object of class mysqli_result could not be converted to string in C:\xampp\htdocs\xxx\dash.php on line 20

I am quite fairly new, and being a old-school coder, simply using mysql_result to grab such data, I am unaware of how to go about this. I have a class->function setup.

Line 20 of dash.php contains:

echo $user->GetVar('rank', 'Liam', $mysqli);

While, the function is:

function GetVar($var, $username, $mysqli)
    {
        $result = $mysqli->query("SELECT " . $var . " FROM users WHERE username = '" . $username . "' LIMIT 1");
        return $result;
        $result->close();
    }

Now, to my understanding, I am meant to convert $result into a string, but I am not fully aware of how to do so. I've tried using a few methods, but to no avail. So I've come to the community to hopefully get a answer, I've also looked around but noticed that all other threads are asking for num_rows, while I just want to grab the string from the query select.

you have to fetch it first, gather the results first then return the way you want, an array, etc. actually its in the php [manual](http://php.net/manual/en/mysqli-stmt.fetch.php) — Kevin, Sep 05 '14 at 13:15
Exactly. What you are actually trying to return is a (raw?) MySQLi object, which of course cannot be converted as string. Also. $result->close will never be executed; Since you close the connection after the return statement, just mentionning. — Alexandre TryHard Leblanc, Sep 05 '14 at 13:24

Kevin · Accepted Answer · 2014-09-05T13:31:44.573

You have to fetch it first before echoing the results. Rough Example:

function GetVar($var, $username, $mysqli) {
    // make the query
    $query = $mysqli->query("SELECT ".$var." FROM users WHERE username = '".$username."' LIMIT 1");
    $result = $query->fetch_assoc(); // fetch it first
    return $result[$var];
}

Then use your function:

echo $user->GetVar('rank', 'Liam', $mysqli);

Important Note: Since you're starting out, kindly check about prepared statements. Don't directly append user input on your query.

score 0 · Answer 2 · answered Sep 05 '14 at 13:16

0

if ($result = $mysqli->query($query)) {
    while($row = $result->fetch_object()) {
            echo row['column_name'];
        }
}
$result->close();

where you see 'column_name put the name of the column you want to get the string from.

answered Sep 05 '14 at 13:16

P Clegg

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My upright most apologies, I mustn't have made the thread clear. I'm using a function to retrieve the data. I've updated what the function is. – Reverb Sep 05 '14 at 13:20
$result can not be converted to a string because it is an array – P Clegg Sep 05 '14 at 13:21

Object can't be converted to a string in MySQLi PHP

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