MySQLi - Right way to execute querys? [duplicate] - php

Question

This question already has answers here:
What to do with mysqli problems? Errors like mysqli_fetch_array(): Argument #1 must be of type mysqli_result and such
(2 answers)
Closed 1 year ago.
First of all, this is my first meeting with MySQLi... I heard that MySQLi is better, but every time I wrote some code, I get
Fatal error: Call to a member function bind_param() on a non-object
My code is this:
<?php
/* Create a new mysqli object with database connection parameters */
$m = new mysqli('localhost', 'root', '', 'mysqlisample');
if(mysqli_connect_errno()) {
echo "Connection Failed: " . mysqli_connect_errno();
exit();
}
$ida=1;
$statement = $m->prepare("SELECT * FROM post WHERE `id` = ?");
$statement->bind_param("i",$ida);
$id = 0;
$post_title = '';
$post_content = '';
$statement->bind_result($id,$post_title,$post_content);
$statement->execute();
while ($statement->fetch()){
echo $id.' '.$post_title.' '.$post_content.'\n'; //These variables will get the values of the current row
}
?>
This is just one of many code sample that I read somewhere, but, none of them working.
What is the right way for executing MySQLi query and print the results?

Answer 1

i worked this out when going through the OReilly book, which was using the old mysql_stuff and none of the examples worked. obviously you'll need to modify it for your tables :) but it works for the tables i have. this will work for prepared statements:
<?php
//this file is just where my db info is, you can use the literal values
require 'login.php';
$db = new mysqli($db_hostname, $db_username, $db_password, $db_database);
$stmt = $db->stmt_init();
$data = array("Emily Bronte", "Wuthering Heights", "Classic Fiction", "1847", "9780553212587");
if($stmt->prepare("INSERT INTO classics(author, title, category, year, isbn) VALUES(?,?,?,?,?)"))
{
$stmt->bind_param('sssss', $data[0], $data[1], $data[2], $data[3], $data[4]);
$stmt->execute();
$stmt->close();
}
?>
this will work for queries:
<?php
require_once 'login.php';
$dbt = new mysqli($db_hostname, $db_username, $db_password, $db_database);
if ($dbt->connect_errno)
die("Unable to connect to MySQL: " . $dbt->connect_errno);
$results = $dbt->query("SELECT * FROM cats");
if (!$results)
die ("Database access failed: " . $db->error);
$dbt->close();
echo "<table><tr> <th>Id</th> <th>Family</th>
<th>Name</th><th>Age</th></tr>";
for ($j = 0 ; $j < $results->num_rows ; ++$j)
{
$row = $results->fetch_row();
echo "<tr>";
for ($k = 0 ; $k < sizeof($row) ; ++$k)
echo "<td>$row[$k]</td>";
echo "</tr>";
}
echo "</table>";
?>

Answer 2

The problem is that $statement->bind_param("i",$ida); returns false, so you can't call the method bind_param on false
See: http://php.net/manual/de/mysqli.prepare.php
Try:
mysqli_stmt_bind_param($statement, "i", $ida);
instead of:
$statement->bind_param("i",$ida);