This document discusses different ways that PHP can receive input from forms and other sources like databases. It covers using GET and POST methods to pass variables between pages via URLs or form submissions. It also provides an example of linking a form to a database by connecting in PHP, obtaining POST variables, writing an SQL query, and redirecting to another page that displays the database records.

1. webdev@rgu
forms and databases in php

2. PROGRAM INPUTPHP CAN RECEIVE INPUT FROM A NUMBER OF
DIFFERENT SOURCES, EACH HANDLED DIFFERENTLY
• FROM HTTP REQUESTS
• KEY/VALUE PAIRS EMBEDDED IN GET
REQUESTS
• DATA INCLUDED IN THE BODY OF A POST
REQUEST
• FROM RESOURCES
• CONNECTING TO A DATABASE TO RETRIEVE
INFORMATION

3. using
GET

4. USING ‘GET’
THE GET KEYWORD ALLOWS US TO RETRIEVE DATA
THAT IS STORED IN THE ADDRESS OF THE WEB PAGE
WWW.MYSITE.COM/RANDOMPAGE.PHP
WWW.MYSITE.COM/RANDOMPAGE.PHP?USERNAME=MIKE

5. sending variables
RANDOMPAGE.PHP?USERNAME=MIKE&GENDER=MALE
TO USE MORE THAN 1 KEY/VALUE PAIR SEPARATE
THEM WITH AN AMPERSAND

6. RANDOMPAGE.PHP?USERNAME=MIKE&GENDER=MALE
START WITH A QUESTION MARK
TO USE MORE THAN 1 KEY/VALUE PAIR SEPARATE
THEM WITH AN AMPERSAND
sending variables

7. RANDOMPAGE.PHP?USERNAME=MIKE&GENDER=MALE
START WITH A QUESTION MARK
VARIABLENAME=VALUE
TO USE MORE THAN 1 KEY/VALUE PAIR SEPARATE
THEM WITH AN AMPERSAND
sending variables

8. <A HREF=“MYPAGE.PHP?USERNAME=MIKE>CLICK ME</A>
WE CAN USE THIS TO PASS INFORMATION
BETWEEN PAGES
$LOCATION = “MYPAGE.PHP?USERNAME=MIKE”;
HEADER($LOCATION);
IN HTML
IN PHP
THERE WILL BE OTHER WAYS THAT YOU’LL FIND
TO USE THIS AS WELL
sending variables

9. TAKE THE VARIABLE FROM GET AND ASSIGN IT TO
A STANDARD VARIABLE. YOU CAN THEN USE IT IN
YOUR CODE
using variables

10. JUST A REMINDER, YOU CAN MAKE YOUR ECHO
STATEMENTS MORE COMPLICATED
CURLY BRACKETS MAKE YOUR LIFE A LOT EASIER,
IT MAY BE WORTH GIVING THEM A GO!
combining in statements

11. displaying information

12. using
post

13. using information from html forms
A SECOND INPUT FOR PHP SCRIPTS IS BY USING
FORMS
• HTML FORMS CAPTURE USER INPUT
• FORM ELEMENTS HAVE NAMES AND WHEN THE
FORM IS SUBMITTED A VALUE IS SET TO THE
CURRENT NAME
• FORM INFORMATION IS ADDED TO
• THE BODY OF THE HTTP REQUEST IF THE FORM
METHOD IS POST
• THE PARAMETERS OF THE HTTP REQUEST IF THE
FORM METHOD IS GET

14. simpleform.html
HTML FILE CONTAINING A FORM

15. submitform.php
PHP FILE READING THE FORM INFORMATION

16. output

17. using get in forms
WE CAN ALSO USE THE GET METHOD IN THIS
EXAMPLE BUT WE WOULD NEED TO ALTER
SIMPLEFORM.HTML AND SUBMITFORM.PHP IN
ORDER TO DO THIS
• THERE ARE LIMITATIONS TO HOW MUCH
INFORMATION CAN BE ENCODED IN A URL STRING
• THIS IS BROWSER SPECIFIC
• SECURITY CONCERNS ALSO EXIST BECAUSE THE
HTTP HEADER IS EXPOSE AND CAN BE INSPECTED
BY THIRD PARTIES
• USING POST MAKES THIS EASIER TO PROTECT

18. linking your form to a
database

19. using a database
ONE OF THE MOST COMMON TASKS THAT YOU
WILL WANT TO DO WITH A WEB FORM IS STORE
THE INFORMATION IN A DATABASE
• COVERED THIS LAST WEEK BUT IT IS WORTH
GOING OVER AGAIN

20. simpleform.html
WE WILL USE THE SAME FORM AS BEFORE

21. submitform.php

22. submitform.php
• CONNECT TO THE DATABASE

23. submitform.php
• CONNECT TO THE DATABASE
• OBTAIN THE $POST VARIABLES

24. submitform.php
• CONNECT TO THE DATABASE
• OBTAIN THE $POST VARIABLES
• FORM THE SQL QUERY

25. submitform.php
• CONNECT TO THE DATABASE
• OBTAIN THE $POST VARIABLES
• FORM THE SQL QUERY
• RUN THE SQL QUERY

26. submitform.php
• CONNECT TO THE DATABASE
• OBTAIN THE $POST VARIABLES
• FORM THE SQL QUERY
• RUN THE SQL QUERY
• REDIRECT TO ANOTHER PAGE

27. viewusers.php
CONNECT TO THE DATABASE

28. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
viewusers.php

29. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
viewusers.php

30. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
viewusers.php

31. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
viewusers.php

32. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
RUN THE QUERY
viewusers.php

33. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
RUN THE QUERY
USE THE WHILE LOOP TO OF THROUGH IT
viewusers.php

34. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
RUN THE QUERY
USE THE WHILE LOOP TO OF THROUGH IT
• FOR ROW THAT EXISTS
viewusers.php

35. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
RUN THE QUERY
USE THE WHILE LOOP TO OF THROUGH IT
• FOR ROW THAT EXISTS
• TURN THE $ROW VARIABLES INTO NORMAL VARIABLES
viewusers.php

36. CONNECT TO THE DATABASE
PUT IN THE HTML HEADERS
START AN UNORDERED LIST
OPEN UP THE PHP TAGS
WRITE THE SQL QUERY
RUN THE QUERY
USE THE WHILE LOOP TO OF THROUGH IT
• FOR ROW THAT EXISTS
• TURN THE $ROW VARIABLES INTO NORMAL VARIABLES
• ECHO THEM OUT
viewusers.php

37. output