How to avoid saving duplicate entries into db

Making a column unique or do a query to check if data exists?

Unique column ? Or use Uniqueness validator.

<?php

$check_existing_record = Model::findFirst(array("input1 = :input1: AND input2 = :input2: AND input3 = :input3: etc ",
"bind" => array("input1" => $input1, "input2" => $input2, "input3" => $input3 etc)
));
if($check_existing_record == false)
{
//keep saving uniqe record
}