Mulitple database on a single php page | Learning Curve- Perfect Tutorial for the beginers

please execute the index.php and see the magic

index.php

<?php
include"connect.php";
$sqlsecond = "select * FROM secondtable order by name asc";
$resultsecond = mysql_query($sqlsecond,$linksecond);
if (!$resultsecond) {
 echo "DB Error, could not list tables\n";
 echo 'MySQL Error: ' . mysql_error();
 exit;
}
while ($row = mysql_fetch_row($resultsecond)) {
  $words=$row[1];
 
 ///check to first table if it exists
$existqry="select * from firsttable where name='$words'";
$existqryresult=mysql_query($existqry,$linkfirst);
$numrowsfirst=mysql_num_rows($existqryresult);
echo $numrowsfirst."--".$words."<br>";
if($numrowsfirst!=1)
{

$qry="insert into firsttable(name)values('$words')";
$executionresult=mysql_query($qry,$linkfirst);
}
}
?>

<?php

include"connect.php";

$sqlsecond = "select * FROM secondtable order by name asc";

$resultsecond = mysql_query($sqlsecond,$linksecond);

if (!$resultsecond) {

echo "DB Error, could not list tables\n";

echo 'MySQL Error: ' . mysql_error();

exit;

}

while ($row = mysql_fetch_row($resultsecond)) {

$words=$row[1];

///check to first table if it exists

$existqry="select * from firsttable where name='$words'";

$existqryresult=mysql_query($existqry,$linkfirst);

$numrowsfirst=mysql_num_rows($existqryresult);

echo $numrowsfirst."--".$words."<br>";

if($numrowsfirst!=1)

{

$qry="insert into firsttable(name)values('$words')";

$executionresult=mysql_query($qry,$linkfirst);

}

connect.php

<?php
$linkfirst = mysql_connect('localhost', 'root', '');
if (!$linkfirst) {
   die('Could not connect: ' . mysql_error());
}
mysql_select_db('testlogin', $linkfirst) or die('Could not select database.');

$linksecond = mysql_connect('localhost', 'root', '');
if (!$linksecond) {
   die('Could not connect: ' . mysql_error());
}
mysql_select_db('testlogin', $linksecond) or die('Could not select database.');
?>

<?php

$linkfirst = mysql_connect('localhost', 'root', '');

if (!$linkfirst) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('testlogin', $linkfirst) or die('Could not select database.');

$linksecond = mysql_connect('localhost', 'root', '');

if (!$linksecond) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('testlogin', $linksecond) or die('Could not select database.');