My problem is that I will not always receive the variables, so I need a way that does not make them mandatory even by declaring them, for example in the query below:
"SELECT * FROM clientes WHERE clientes.nome = :nome";
Var :nome is required;
Then I need that even if the variable :nome does not contain a value, the query returns me all the clients
I recommend doing this directly to php.
You can use if to do this, as Stéfano suggested, or in a simpler way:
$sql = empty($nome) ? "SELECT * FROM clientes" : "SELECT * FROM clientes WHERE clientes.nome = :nome";
Verify with IF .
if(!empty($nome)){
$where = "clientes.nome = :nome";
} else {$where = "";}
$query = "SELECT * FROM clientes WHERE $where";
You can edit the else to add other rules in where .