Can I use array_splice to delete element multidimensional array without error in PHP?

I got this code:

function deleteClient(){
    global $database;
    $input = 2;
    if (array_key_exists($input, $database)){
        $database.array_splice($database, $input, 1);
        echo "Client with id $input deleted succesfully";
    } else {
        echo "Client with this id doesn't exist";
    }
}

Variable $database is my two-dimensional array. Although array_splice deletes array with given index, it shows an error “Warning: Array to string conversion”. Everything else works properly.

I tried doing it with unset:

function deleteClient(){
    global $database;
    $input = 2;
    if (array_key_exists($input, $database)){
        unset($database[$input]);
        echo "Client with id $input deleted succesfully";
    } else {
        echo "Client with this id doesn't exist";
    }
}

It doesn’t return an error, but makes gaps in array which breaks another function.