Posting into database using mysqli

Question

I am learning php and trying to make the following work:

<?php
require_once("db_connect.php");

    // TODO - Check that connection was successful.

    $dname = $_POST["dname"];
    $daddress = $_POST["daddress"];


    $stmt = $mysqli->prepare("INSERT INTO test (dname, daddress) VALUES (?, ?)");

    // TODO check that $stmt creation succeeded

    // "s" means the database expects a string
    $stmt->bind_param("s", $dname, $daddress);

    $stmt->execute();

    $stmt->close();

    $mysqli->close();
?>

It works with just one bind_param but not 2. If $daddress was removed from the code then it posts. The form has 26 posts into database I am doing it with 2 at the moment to keep it minimal.

I get the following error when the form is submitted.

Warning: mysqli_stmt::bind_param() [mysqli-stmt.bind-param]: Number of elements in type definition string doesn't match number of bind variables in /home/mymotorsportco/public_html/entry/actions/entry.php on line 15

Answer 1

As per PHP manual:

types

A string that contains one or more characters which specify the types for the corresponding bind variables

i - corresponding variable has type integer

d - corresponding variable has type double

s - corresponding variable has type string

b - corresponding variable is a blob and will be sent in packets

You have to add types for all the parameters you are binding. So if the second parameter is a string, you have to do

$stmt->bind_param("ss", $dname, $daddress);

Answer 2

You need to pass in the same amount of characters into the first argument, as you have values to inject into your query. For example:

 $stmt->bind_param("ss", $dname, $daddress);

Will say that the first param is a string, as well as the second. Additionally, the following will tell the database to expect a string, then an int:

 $stmt->bind_param("si", $dname, $daddress);

Big props for using prepared statements, most newbies will throw in variables with absolutely no sanitation. You're on the right track!