how to create search system using filter

Question

I have a search system where I search users filtering by: name, age and email. If I filter by name and age and email, everything happens well, but if I filter only by age, for example, nothing is returned same try in the correct database. I think I’m doing it the wrong way, because I use the AND operator in the query, I mean, I want all three to return true, but that’s not really what I want. I want to filter by: age, or by age and email, or by age and email and name.

<?php 
$nome = addslashes($_GET['nome']);
$idade = addslashes($_GET['idade']);
$email = addslashes($_GET['email']);
    $sql = $pdo->query("SELECT * FROM usuarios WHERE nome = '$nome' AND idade = '$idade' AND email = '$email' ");

?>

Answer 1

I did not find errors in the code, for me it worked perfectly, what may be occurring is that your variable that receives the $_GET age is not receiving any value, in which case I recommend that you run the code below to check if the variables are receiving values.

<?php 
$nome = addslashes($_GET['nome']);
$idade = addslashes($_GET['idade']);
$email = addslashes($_GET['email']);

//verifica se todos os campos estao recebendo valores
if(!is_null($nome) && !is_null($idade) && !is_null($email)){
    echo "Todos os campos estão enviando valor";
}else{
    echo "Algum campo nao esta correto";
}
?>

Another tip I have for you, is to use the PDO this way to search data in the database, I realized is using PDO, so is in search of greater security for your code.

//select de dados de uma forma mais segura
$sql = $pdo->prepare("SELECT nome, idade, email FROM usuarios WHERE nome = :nome AND idade = :idade AND email = :email");
$sql->bindParam(':nome', $nome, PDO::PARAM_STR);
$sql->bindParam(':idade', $nome, PDO::PARAM_INT);
$sql->bindParam(':email', $email, PDO::PARAM_STR);
$sql->execute();
$linha = $sql->fetch(PDO::FETCH_ASSOC);
?>

Anyway, I hope I helped my friend.

Answer 2

Here is an example of how to mount a conditional query according to the fields sent:

<?php
$where = array();
$nome = "";
$idade = "";
$email = "";
if(isset($_GET['nome'])) {
    if(($_GET['nome'] <> "") {
        $nome = $_GET['nome'];
        $where[] = 'nome LIKE :nome';
    }
}
if(isset($_GET['idade'])) {
    if($_GET['idade'] <> ""){
        $idade = $_GET['idade'];
        $where[] = 'idade LIKE :idade';
    }
}
if(isset($_GET['email'])) {
    if($_GET['email'] <> ""){
        $email = $_GET['email'];
        $where[] = 'email = :email';
    }
}

if(count($where)) {
    $sql = $pdo->prepare("SELECT nome, idade, email FROM usuarios WHERE ".implode(' AND ',$where));

    if($nome <> "") {
        $sql->bindParam(':nome', $nome, PDO::PARAM_STR);
    }   

    if($idade <> ""){
        $sql->bindParam(':idade', $idade, PDO::PARAM_INT);
    }   

    if($email <> ""){
        $sql->bindParam(':email', $email, PDO::PARAM_STR);
    }

    $sql->execute();

}
?>

Answer 3

Change your query to this

$sql = $pdo->query("SELECT * FROM usuarios WHERE nome LIKE '$nome' OR idade = '$idade' OR email LIKE '$email' ");