How to select data from a specific user using INNER JOIN - php

Question

I want to select data from a specific user. When he is logged in on the website he will see information related to him.
I'm using INNER JOIN and I need to select data related to his login or id.
Any account that I use to login, I can access all exercises registered =/
On this case I'm using an ID.
Is something wrong with the query?
I don't get any errors from PHP. Where can I put the WHERE clause?
Code:
<?php
$login = $_SESSION['login'];
$consulta = mysqli_query($conexao,"SELECT exercicios.nome_exercicio AS nome_exc,
exercicios.repeticoes_exercicio AS rep_exc,
exercicios.serie_exercicio AS serie_exc
FROM exercicios
INNER JOIN usuarios ON usuarios.id_usuario = exercicios.id_usuario WHERE exercicios.id_usuario = '5'");
if(mysqli_num_rows($consulta)> 0){
echo "<div class='table-responsive'><table class='table table-responsive'>
<tr><td>Nome</td><td>Repetições</td><td>Série</td></tr>";
while ($exercicio = mysqli_fetch_assoc($consulta))
{
print"<tr>
<td>$exercicio[nome_exc]</td>
<td>$exercicio[rep_exc]</td>
<td>$exercicio[serie_exc]</td>
</tr>";
}
echo " </table></div>";
}
else {
echo "<h3>Seu instrutor ainda não cadastrou exercícios</h3>";
}
?>

Answer 1

You are missed some important things, for example, what data are you storing in your session variable login?
$login = $_SESSION['login'];
When a user send the login data first time (for example email and password), you will search the data on the database (table accounts or users or the table you need) and then if exist you should store the user data on session (the id is the most important). So, when you need to access to the exercises of the user, you need only to specify the correct user id on the where condition like ($login in this example is an array with user data):
"SELECT .... FROM .... WHERE id = {$login['userId']}"
Hope this explanation will be enough to fix your problem.