duplicate value should not be inserted

[milo_pantig]

this PHP script should not insert the same value🙂 but why it still inserting duplicate value. Anybody can help us!

if ($_POST['Insert']) {
while($row=mysql_fetch_array($selectQuery))
{
// echo $i++ ."**". $row['homeTel'] . "<br>";
$homeTel=$row['homeTel'];

	foreach ($matches[0] as $u => $landlord) 
	{	 
		 $matches1 = $matches[1][$u];	
//		 echo "<br>Name: " .  $matches1;
		 $matches2 = htmlspecialchars($matches[2][$u],ENT_QUOTES);
//		 echo "<br>Add: " .  $matches2;		 
		 $match0 = $match[0][$u];
//		 echo "<br>tel: " .  $match0;				 
		 if (($match0 != $homeTel) || ($matches2 != 'NULL'))
		 {
			 $insertQuery="insert into ".homerentaltable."(homeName,homeAddress,homeTel)
			 values('$matches1','$matches2','$match0')";
			 mysql_db_query($database_name,$insertQuery) or die ("Failed " . $insertQuery);
		}			 
	}		
}		 

} 2

[Roger_Ramjet]

Create a Unique index on the column that cannot have duplicate values in it and the table will protect itself. When you run the insert query use the 'IGNORE' keyword to stop the query from aborting when duplicate keys are encountered.