Working on sell.php now. Trying out Sell, I naturally find the need to replenish shares of some stock after selling, for testing purposes. When I try to manually insert, like instructions said to do in Portfolio, I enter appropriate user_id, symbol and number of shares. And then nothing happens when I refresh that user's portfolio. Also, noticed that my IDs in Portfolio table are not incrementing consecutively.
I hadn't actually watched the video, so thank you, ronga, for your suggestion. I should slow down and review all the information provided before becoming frustrated at my inability to solve a problem.
I dchange my "Portfolio" table by getting rid of "user_id," which I found was unncessary, instead just using "id," "symbol," and "shares," making "id" and "shares" a joint key. I also had to change some of my queries to "Portfolio" in a couple of my controllers, making sure superglobal variable "$_SESSION" referenced "id" in "users" table and not "user_id" in "Portfolio" table. Oops.