Join two MySQL tables with PHP - php

Question

For example, I have created two pages and two MySQL tables.
Index.php & citys.php
citys
ID City Country Population
--------------------------------------
1 Amsterdam NL 1500000
2 Rotterdam NL 900000
3 Dusseldorf DE 1800000
comments
ID City Name Comment
---------------------------------
1 Dusseldorf Jack Great city!
2 Dusseldorf John Beautiful
3 Rotterdam Emy Love it
At the moment I only use the table citys like this:
index.php linking to citys.php with:
<a href='citys.php?cmd=menu&id=";echo $row['id'];echo "'>
And citys.php use this code to show the data from MySQL:
<?php
include "connect.php";
if(!isset($cmd))
{
if($_GET["cmd"]=="menu" || $_POST["cmd"]=="menu")
{
if (!isset($_POST["submit"]))
{
$id = $_GET["id"];
$sql = "SELECT * FROM citys WHERE id=$id";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);
?>
<?php echo $row["City"] ?>
<br><br>
<?php echo $row["Country"] ?>
<br><br>
<?php echo $row["Population"] ?>
Until here everything is showing up and working fine.
But I also want to show the comments on page 2. So the query has to be edited to also get the right data from the table comments.
I tried different examples from internet that I have edited myself like:
<?php
include "connect.php";
if(!isset($cmd))
{
if($_GET["cmd"]=="menu" || $_POST["cmd"]=="menu")
{
if (!isset($_POST["submit"]))
{
$id = $_GET["id"];
$sql = "SELECT citys.*, comments.* FROM citys, comments WHERE citys.id=$id AND comments.city=citys.city";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);
?>
But nothing works.
How can I fix this?
The query from VIPIN JAIN's answer works, but there is one problem left:
Query:
$sql = "SELECT * FROM citys LEFT JOIN comments ON comments.city=citys.city WHERE citys.id=$id";
If the table 'comments' has three rows, this code shows only the last two but not the first:
<?php
while($row = mysql_fetch_array($result)) {
echo "<br><br>";
echo $row['name'];
echo "<br>";
echo $row['comment'];
}
?>
And if I try this it only shows the first row.
<?php echo $row["name"] ?>
<br>
<?php echo $row["comment"] ?>
I don't know why the first record is left away in the loop.

Answer 1

Use this query
$sql = "SELECT * FROM citys LEFT JOIN comments ON comments.city=citys.city WHERE citys.id=$id";
Use leftjoin for this type of work

Answer 2

select * from citys
left join comments on comments.city = citys.city
where citys.id=$id