MySQL Selecting A Key From A Seperate Table - php

Question

I am currently fetching data from a group of location MySQL tables here is what I currently have
$query = "SELECT Name, CountryCode, Population FROM City WHERE (Population > '6000000') ORDER BY Population DESC";
$result = mysqli_query($link, $query);
while($row = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>$row[0]</td>";
echo "<td>$row[1]</td>";
echo "<td>$row[2]</td>";
echo "</tr>\n";
}
mysql_close($link);
The thing I am trying to figure out is how to convert the CountryCode to the actual country. Here is how I would call the country table to get the name
SELECT Name FROM Country WHERE Code = 'CountryCode';
How would I combine these two statements into one?
EDIT: Here is what I got to work. Is this considered a JOIN?
$query = "SELECT a.Name, a.CountryCode, a.Population, b.Code, b.Name FROM City a, Country b WHERE (a.CountryCode = b.Code) AND (a.Population > '6000000') ORDER BY Population DESC";
$result = mysqli_query($link, $query);
while($row = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>$row[0]</td>";
echo "<td>$row[2]</td>";
echo "<td>$row[4]</td>";
echo "</tr>\n";
}
mysql_close($link);

Answer 1

U need to join City table and Country table having one primary key and one foreign key.
Read about Natural Join. It's easy.

Answer 2

You can use this query:
$query = "SELECT city.Name,country.Name,city.CountryCode,city.Population from city INNER JOIN country where country.CountryCode=city.CountryCode and city.population>5000 ORDER BY city.Population DESC";
This is working fine.