不要重复相同的记录[关闭]

How do I not to repeat the fields in the process of introducing the records, I do not repeat the same user history

$query="INSERT INTO `cashiers` ( `cashiers_CashierID` , `cashiers_CashierOpenDate` , `cashiers_User` , `cashiers_Status` , `cashiers_Delete`  ) VALUES ('', '$cashiers_CashierOpenDate', '$ausers_ID', '0','0');";
            mysql_query($query);

Well aside from the PDO issue, quick one given you are going to insert the records one by one is something like

If Not Exists(Select something from somewhere where something = ?)
  Insert Values (?,... )

Where ? is the key for the table.