Create dynamic sites with PHP & MySQL - Editing data
(Page 14 of 16 )
So far we have viewed and deleted database content. But sometimes we need to edit database content. For this we will modify our previously coded input.php file. By now you are familiar with the concept of passing variables by URL. We will call this modified script addedit.php:
Hmmm... the code looks quite complex. But really it isn't. Previously input. php had two features: it could add information to the database or could show the form. We'll add two more features to it: the ability to show the same form but with values of a particular person already there and the ability to update records for that person. The SQL commands for entering new information and updating existing information are different, so we can't use our previous code for entering information.
The script searches for the $submit variable. If it contains some value, then someone submitted new data and the information is entered into the database. If $submit does not contain any value, then someone might have just posted their updated information, so we check $update. If it contains a value, then we update that person's record with the SQL statement "UPDATE personnel SET fieldname1= '$variablename1', fieldname2= '$variablename2' ......... WHERE id=$id";". Otherwise, if someone provided the id in the query string, we show that person's information, but this time in a form so he may change it. If all these are not the case, we simply have to show the old form.
Experiment with the script. Open it with your browser to see what comes up. Then call it providing query string ?id=1. Change the information and click update. Verify whether the database is updated by viewing the database with viewdb3.php.
Another new element was just introduced. It is the global PHP variable $PHP_SELF. This variable always contains the name of the script it is in and its location. We have used this variable in a 'form action' so no matter what you name this file, this script will always post information to itself.
Once again we modify our viewing script incorporating this feature. Here's the listing for viewdb4.php:
/ 54 