by Mohamed El Desouki [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز – السعودية – الخرج in this lecture we continue in lesson 3 from section 13 of the course , it covers the following 1-Modifying Tables Using Alter Table Statement. 2– How to Add and Drop columns to Tables 3- How to modify existing columns.