MySQL Introduction

There are a large number of database management systems currently available, some commercial and some free.

Some of them : Oracle, Microsoft Access, Mysql and PostgreSQL.

These database systems are powerful, feature-rich software, capable of organizing and searching millions of records at very high speeds.

Understanding Databases, Records, and Primary Keys

Every Database is composed of one or more tables.

These Tables, which structure data into rows and columns, Impose organization on the data.

The records in a table(below) are not arranged in any particular order.

To make it easy to identify a specific record,therefore, it becomes necessary

BookIdBookNamePrice($)
1The Shining250
2Shutter Island300
3The Overlook180
4Safe Harbour200
5Trunk Music300

to add a unique identifying attribute to each record, such as a serial number or sequence code.
In the preceding example, each record is identified by a unique “record ID” field;
this field is referred to as the Primary key for the table.

Understanding Relationships and Foreign Keys(RDBMS)

You already know that a single database can hold multiple tables.
In a Relational database management system(RDBMS), these tables can be linked to each other by one or more common fields, called foreign keys.

These foreign keys make it possible to create one-to-one or one-to-many relationships between different tables, and combine data from multiple tables.

GenreIdGenreName
1Horror
2Crime
3Romance
AuthorIDAuthorName
1Stephen King
2Danielle Steele
3Dennies Lehane
4Michael Connelly
5Nora Roberts
BookIdBookNameGenerIDAuthorID
1The Shining11
2Shutter Island23
3The Overlook11
4Safe Harbour14
5Trunk Music32
6Sisters32
7Blodd Broters14
8Pet Sematary35

What is Database administrator(DBA) ?

Database administrator is the super user of database, he has unrestricted rights and privileges to access database, grant permission to other database users.

What is Database user(DBU) ?

Database user is the person who uses the database in a restricted privileges, provided by database administrator.

Download MySQL Database

If you have installed PHP’s WAMP or XAMPP server, then mysql database already exists. if you don’t have then download mysql database from herehttp://www.mysql.com


  • Faizan

    How to insert data from textarea to database?

    • sangita machhi

      Hello..I m sangita ..I wanna give online test but I can’t choose the category .please answer.

  • Narayan

    hi
    please post the small $ sample projects with database.

  • Narayan

    all post are very good. u have done great worke.
    please post login,registration and insert,update & delete in PHP with separate database.

  • sangita machhi

    Hello.. I m sangita from Surat Gujarat. I wanna give online test.. But I can’t choose the category. Plz Answer ..

    • Hi Sangita, Let me check and update the question

  • sachn

    why we use css properties autocomplete:off;

    • Autocomplete allows the browser to predict the value. When a
      user starts to type in a field, the browser should display options to fill in
      the field, based on earlier typed values.

      eg.

  • Neeraj Kumar

    sanjeev sir i have a query to ask…. let us suppose we have 2 tables in a database…(1.district and 2.regions) district table consist of two fields i.e district code and district name, similarly regions table has 2 fields i.e. region code and region name…. i want to map the regions with the relevant district… in the html i have 2 dropdowns and i am fetching there the names of the district and regions in the dropdowns from the database…. but at the back end i want to save the district and region codes which are integers associated with those names which are selected by the user at the interface page..in a different table. so the user can select the district and region on the page and at the backend the table should be populated with the corresponding codes… waiting for your reply…

  • Tauras Neeraj

    sir how to insert the multiple select values into data base???? m facing problem in this… insert query only inserting only a single value from sthose selected options…. i want to insert all the selected items in the database…

  • Cheru Passah

    sir how to decrypt the selected column using aes_encryption and decryption? would be helpful if you help tq

    • try aes_decrypt()

      Why u want to descrpt ? for login page?