forms and databases in php

webdev@rguforms and databases in php

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

using

GET

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

sending variablesRANDOMPAGE.PHP?USERNAME=MIKE&GENDER=MALE

TO USE MORE THAN 1 KEY/VALUE PAIR SEPARATE THEM WITH AN AMPERSAND

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

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

<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

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

using variables

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

displaying information

using

post

using information from html formsA 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

simpleform.htmlHTML FILE CONTAINING A FORM

submitform.phpPHP FILE READING THE FORM INFORMATION

output

using get in formsWE 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

linking your form to a

database

using a databaseONE 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

simpleform.htmlWE WILL USE THE SAME FORM AS BEFORE

submitform.php

submitform.php

• CONNECT TO THE DATABASE

submitform.php

• CONNECT TO THE DATABASE • OBTAIN THE $POST VARIABLES

submitform.php

• CONNECT TO THE DATABASE • OBTAIN THE $POST VARIABLES • FORM THE SQL QUERY

submitform.php

• CONNECT TO THE DATABASE • OBTAIN THE $POST VARIABLES • FORM THE SQL QUERY • RUN THE SQL QUERY

submitform.php

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

viewusers.php

• CONNECT TO THE DATABASE

• CONNECT TO THE DATABASE • PUT IN THE HTML HEADERS

viewusers.php

• CONNECT TO THE DATABASE • PUT IN THE HTML HEADERS • START AN UNORDERED LIST

viewusers.php

• CONNECT TO THE DATABASE • PUT IN THE HTML HEADERS • START AN UNORDERED LIST • OPEN UP THE PHP TAGS

viewusers.php

• CONNECT TO THE DATABASE • PUT IN THE HTML HEADERS • START AN UNORDERED LIST • OPEN UP THE PHP TAGS • WRITE THE SQL QUERY

viewusers.php

• 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

• 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

• 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

• 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

• 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

output