What is Call to a member function?

bakertaylor28

What is Call to a member function bind_param() on bool in /file.php:60 n the context of the following code, and how do I fix it?

The Code:

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<?php

// Start PHP Session, if not already started. Login verification script will be placed in this section later.

session_start();

// Connect to database. Change this to the proper SQL connection info.

$DATABASE_HOST = 'localhost';

$DATABASE_USER = 'user';

$DATABASE_PASS = 'password';

$DATABASE_NAME = 'library';
 
// Try and connect using the info above. Return error if unsucessful.

$con = mysqli_connect($DATABASE_HOST, $DATABASE_USER, $DATABASE_PASS, $DATABASE_NAME);

if ( mysqli_connect_errno() ) {

    // If there is an error with the connection, stop the script and display the error.

    die('Failed to connect to MySQL: ' . mysqli_connect_error());

}
 
// Now we check if the data from the lookup form was submitted, isset() will check if the data exists.

if ( !isset($_POST['call']) ) {

    // Could not get the data that should have been sent.

    die('Please fill in a valid Call Number!');

}
 
//Start HTML5 code for the output

echo '<!DOCTYPE html>';

echo '<head>';

echo '<style>';

echo 'table {';

echo 'font-family: arial, sans-serif;';

echo 'border-collapse: collapse;';

echo 'width: 100%;';

echo '}';

echo 'td, th {';

echo 'border: 1px solid #dddddd;';

echo 'text-align: left;';

echo 'padding: 8px;';

echo '}';

echo 'tr:nth-child(even) {';

echo 'background-color: #dddddd;';

echo '}';

echo '</style>';

echo'</head>';

echo '<body>';

echo '<table><tr>';

echo '<th>Call No.</th>';

echo '<th>Subject</th>';

echo '<th>Title</th>';

echo '<th>Author</th>';

echo '<th>Description</th>';

echo '<th>Publisher</th>';

echo '<th>Year Pub.</th>';

echo '<th>Year Rev.</th>';

echo '<th>Cheked Out</th>';

echo '</tr>';
 
// Prepare our SQL, preparing the SQL statement will prevent SQL injection. call is a Call No.

// e.g. in the format 320.01SIM ,etc.

$stmt = $con->prepare('SELECT * FROM catalog WHERE call = ?');
 
// Bind parameters (s = string, i = int, b = blob, etc), in our case the call number is a varchar string so we use "s"

    $stmt->bind_param('s', $_POST['call']);
 
//Execute the prepared statement

    $stmt->execute();

    $result = $stmt->get_result();
 
// Loop through the rows of the table that match the result and output to html table.

    while($row = $result->fetch_assoc()) {

      echo "<tr><td>" . $row['call'] . "</td><td>" . $row['subject'] . "</td><td>" . $row['title'] . "</td><td>" . $row['author'] . "</td><td>" . $row['description'] . "</td><td>" . $row['publisher'] . "</td><td>" . $row['pubyear'] . "</td><td>" . $row['revision'] . "</td><td>" . $row['out'] . "</td></tr>";

        }
 
//Close the SQL connection.        

    $stmt->close();
 
//Finish up HTML5 code and exit this script.

echo '</table></body></html>';

exit;

?>

Dormilich

in line 57 $con->prepare() encounters an error and returns false. Hence the error.

bakertaylor28

That would seem to mean there's something wrong with the statement:

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('SELECT * FROM catalog WHERE call = ?')

Other than that, I can't see any reason it would return "false". Of course some of the database fields do contain rather large chunks of data, which makes me wonder if SQL is even the right device to use for what I'm trying to do.

Dormilich

I'd suspect that call is a reserved keyword.

Dormilich

it is. Cf. https://dev.mysql.com/doc/refman/8.0...8-0-detailed-C

bakertaylor28

That turned out to be the problem. had to change both "call" and "out" in the SQL table because of them being reserved keywords. Thanks a bunch.

What is Call to a member function?

✓ answered by Dormilich

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