Display icon if database value exeed some limit

My php application i want to display a icon when it exeed some value. Eg: I have rainfall values in my database and if some value exeed the given higher limit the icon sholud display on my web page. How can i do that?

 

can you elaborate? what rainfall values?

 

are you able to read the data from your database? or do you need the entire php code to connect to the database, read the value, compare it and then display the picture
if you are able to read the value already then its just a matter of comparing it with your value like so:

$database_value; // The value read from the database!
$comparison = 12; //if you want the number that you want to compare with to be 12 
if ($comparison > $database_value) {
echo "<img src='img url of if number exceeds'/>";
}

Code (markup):

 

How can i compare it?

 

use left join

sample

select t1.*,t2.* from tableone as t1 left join tabletwo as t2 on t1.id = t2.id order by rainfall