Curriculum Flowchart generator.
We are using PHP and MySql for our database.
in the Subject table:
subNo as Pk
Description
Units
Prerequisite
After the creation of the curriculum,
*on the second column specifies the subjects prerequisite

we have a functionality in which a flowchart will be generated
out of the curriculum made something like this;

An arrow will point to the subject IT 120 because it is
a prerequisite of IT 110.
Question:
How can we code this in PHP?
We really need your help.