How to get the user_id from mysql using procedural php? - php

Question

I am an android/java developer and Im struggling with php.
I've made it as far as inserting a new user in the DB, now I want to get their ID.
What do I do with the result? I want to assign it to a variable.
$query = "SELECT user_id FROM users WHERE user_email = '" . $user_email . "'";
$result =
PS: Im using mysql, not mysqli.
EDIT: Here is what I did:
$query = "SELECT user_id FROM users WHERE user_email = '" . $user_email ."';";
$store_info = mysql_fetch_array(mysql_query($query));
$user_id = $store_info['user_id'];
$response["message"] = "User created with id: " . $user_id;
echo json_encode($response);
And the error message after inserting (successfully) the user in the db:
null{"success":3,"message":"User created with id: "}

Answer 1

I assume that your are using MySQLi API
$query = "SELECT user_id FROM users WHERE user_email = '$user_email'"; //Your Query
$store_info = mysqli_fetch_array(mysqli_query($connection, $query));
//Execute the query, fetch the result, it's just one result so no need for a while loop
echo $store_info['user_id']; //echo id
As per the comments, you requested a mysql_() version so here you go...
$query = "SELECT user_id FROM users WHERE user_email = '$user_email'"; //Your Query
$store_info = mysql_fetch_array(mysql_query($query));
//Execute the query, fetch the result, it's just one result so no need for a while loop
echo $store_info['user_id']; //echo id
Still consider using mysqli_() or PDO instead. Why? Because mysql_() is now deprecated, read the red box on the documentation page which says...
Refer this answer for PDO tutorial

Answer 2

Here is the PDO variant:
<?php
//credentials
$host = 'localhost';
$user = "user";
$password = '';
$db_name = 'test';
$port = 3306;
//connection to the database
try
{
$connection = new PDO("mysql:host=$host;port=$port;dbname=$db_name", $user, $password);
$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch (PDOException $e)
{
echo 'Connection failed: ' . $e->getMessage();
}
//prepare and execute SELECT statement
$sth = $connection->prepare("SELECT user_id FROM users WHERE user_email = :email");
$sth->execute(array(':email' => $user_email));
$record = $sth->fetch(PDO::FETCH_ASSOC);
print $record["user_id"];

Answer 3

If you use mysql (but you shouldn't, it's deprecated) :
$result = mysql_query("SELECT user_id FROM users WHERE user_email = '$user_email'");
$row = mysql_fetch_row($result);
echo $row[0]; // you result (id)

Answer 4

Connection:
define("HOST","localhost");
define("USER","mysql_username");
define("PASS","password");
$conn = mysql_connect(HOST,USER,PASS) or die("<h3>Sorry, could not connect to MySQL. Please Try Again</h3>");
$db = mysql_select_db(DBNAME,$conn) or die("<h3>Sorry, could not connect to Database. Please Try Again</h3>")
Query:
$query = "SELECT user_id FROM users WHERE user_email = = '" . $user_email . "'";
$result = mysql_query($query);
$row=mysql_fetch_assoc($result);

Answer 5

Your error comes because of the error in SQL query: you used = operator twice:
$query = "SELECT user_id FROM users WHERE user_email = = '" . $user_email . "'";
Must be:
$query = "SELECT user_id FROM users WHERE user_email = '" . $user_email . "'";