PHP Query and delete database multiple-column duplicate data method (implemented by Array function) _php techniques

This article describes a PHP query and deletes a database of multiple-column duplicate data methods. Share to everyone for your reference, specific as follows:

<?php
$con = mysql_connect ("localhost", "root", "");
if (! $con)
{
    die (' Could not connect: '. Mysql_error ());
}
$db _selected = mysql_select_db ("test_db", $con);
if (! $db _selected)
{
    die ("can/" T use test_db: ".) Mysql_error ());
}
$sql = "SELECT * from friend";
$result =mysql_query ($sql, $con);
while ($myrow =mysql_fetch_row ($result))
{
    $arr _data[$myrow [0]]= $myrow [1]. " -". $myrow [2];
}
$arr _unique=array_unique ($arr _data);
$arr _rep=array_diff_assoc ($arr _data, $arr _unique);
Displays the amount of
echo count ($arr _data). -". Count ($arr _unique);
foreach ($arr _rep as $key => $value) {
  $sql _del = "DELETE from friend WHERE id = ' {$key} '";
  $result =mysql_query ($sql _del, $con);
Some code
mysql_close ($con);
? >

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I hope this article will help you with the PHP program design.