24-01-2013, 02:33 PM
Databases and the Web
Databases.ppt (Size: 269 KB / Downloads: 19)
Definition
A database is an organized collection of data whose content must be quickly and easily
Accessed
Managed
Updated
A relational database is one whose data are split up into tables, sometimes called relations
Normalization(read logical organization)
First Normal Form (1NF)
All attributes are single valued & non-repeating
Second Normal Form (2NF)
Must be 1NF & must have primary key
Each non-primary key attribute must be functionally dependent on primary key
Third Normal form (3NF)
Must be 2NF
Each non-primary key attribute must be dependent only on primary key
Keys
Primary
An attribute or group of attributes which uniquely identifies each record in a table
May not be a Null value
Foreign
used primarily for enforcing referential integrity, but also for establishing relationships between the two tables
Structured Query Language(SQL)
Pronounce “Sequel” or “Ess Que Ell”
Industry standard language of (Relational) Databases
Allows for complete
Table Creation, Deletion, Editing
Data extraction (Queries)
Database management & administration
Requirements for a Database Web Interface
Your database (Access, MySQL)
A Web server with appropriate RDBMS
A way of connecting the two(Common Gateway Interface – CGI – scripts and SQL)
Security concerns
ASP Security
Apart from various Internet Information Services (IIS – Window’s Web service) security holes (for viruses and worms), security is quite good.
Use https:// if you want to protect content over the internet – provides Secure Socket Layer (SSL) security
Perl Security
Perl/MySQL can be made secure apart from one serious flaw as implemented at UVa:
Because web files must be readable by the world (unix permissions), anyone with an account on the server where you run the php code can see the code, including your MySQL $password!
A couple of exceptions to this flaw are as follows:
If you secure your server so that there are no other users on it
(It may* be possible to compile Perl scripts into binary executables using perlcc. Then you must hide or remove your source code containing the MySQL password)
One other possible poor to fair workaround: use .htaccess to password protect your php directory (limited access)
See the passwords link, security links page