BENR2423
Chapter 7:
Database and RESTful API
Cloud System
• A communications protocol for transmitting
hypermedia documents, such as HTML.
• Designed for communication between web
browsers and web servers.
GET /index.html HTTP/1.1
Host: www.google.com
Browser Web Server
HTTP/1.1 200 OK
Content-Type: text/html
<html><head>…
Hypertext Transfer Protocol (HTTP)
• Basic HTTP request methods (HTTP verbs)
• GET
• POST
• DELETE
• PATCH
• PUT
• CONNECT
• OPTION
• TRACE
Hypertext Transfer Protocol (HTTP)
• A style of software architecture and approach to
communications often used in web services
development
• A Web service that follows these guidelines is
called RESTful
GET /index.html HTTP/1.1
Host: www.google.com
Browser Web Server
HTTP/1.1 200 OK
Content-Type: text/html
<html><head>…
Representational State Transfer (REST)
• A Web service must provide its Web resources in a textual
representation
• The Web resources should be linked to a specific URL
• Each URL is called a request while the data sent back to you
is called a response
request
GET /index.html HTTP/1.1
Host: www.google.com
Browser Web Server
HTTP/1.1 200 OK
Content-Type: text/html
<html><head>…
response
Representational State Transfer (REST)
• The Anatomy of A Request
• The endpoint : www.google.com
• The method
• The headers
• The data (or body)
GET /index.html HTTP/1.1
Host: www.google.com
Browser Web Server
HTTP/1.1 200 OK
Content-Type: text/html
<html><head>…
Representational State Transfer (REST)
• REST uses URI to identify resources
• http://portalfkekk.utem.edu.my/web/index.php?search=utem
• http://portalfkekk.utem.edu.my/web/index.php/deans-welcome-
note/
• http://portalfkekk.utem.edu.my/web/index.php/prospective-
students/programme-offered/benr/
The Endpoint
• The methods provide meaning for the request to
perform four basic actions: Create, Read, Update
and Delete (CRUD):
• GET : Read Request
• POST : Create Request
• DELETE : Delete Request
• PATCH : Update Request
The Method (HTTP Verbs)
• This is the default request method to get a resource
from a server.
• If you perform a GET request, the server looks for
the data you requested and sends it back to you.
• In general, a GET request performs a READ
operation.
GET http://benr2423.com/books
Retrieve all books
HTTP GET
• This request is used to create a new resource on a
server.
• If you perform a POST request, the server creates a
new entry in the database and tells you whether the
creation is successful.
• In general, a POST request performs an CREATE
operation.
POST http://benr2423.com/student
body: { name: 'Soo', matric: 'B0201110011’}
Create a new student
HTTP POST
• This request is used to update a resource on a server.
• If you perform a PATCH request, the server updates an
entry in the database and tells you whether the update
is successful.
• In general, a PATCH request performs an UPDATE
operation.
PATCH http://benr2423.com/student/B0201110011
body: { name: 'Soo YG', matric: 'B0201110011'}
Update student info with matric B0201110011
HTTP PATCH
• This request is used to delete a resource from a
server.
• If you perform a DELETE request, the server deletes
an entry in the database and tells you whether the
deletion is successful.
• In other words, a DELETE request performs a
DELETE operation.
DELETE http://benr2423.com/student/B0201110011
Delete student with matric B0201110011
HTTP DELETE
• Headers are used to provide information to both
the client and server.
• It can be used for many purposes, such as
authentication and providing information about the
body content.
• References:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers
The Headers
• The data (sometimes called body or message)
contains information you want to be sent to the
server.
• This option is only used with POST, PATCH or
DELETE requests
The Data (Or Body)
• An API is an application programming interface. It
is a set of rules that allow programs to talk to each
other
• Developer creates the API on the server and allows
the client to talk to it
REST API
• HTTP status codes let you tell the status of the
response quickly.
• The range from 100+ to 500+. In general, the
numbers follow the following rules:
• 200+ means the request has succeeded.
• 300+ means the request is redirected to another URL
• 400+ means an error that originates from the client has
occurred
• 500+ means an error that originates from the server has
occurred
HTTP Status Codes And Error Messages
