MySQL Database

Part 1: Introduction to MySQL (Explore more details by clicking on Read More....)

Click here to watch complete video playlist on MySQL Database on Youtube:

https://youtube.com/playlist?list=PL_VWo2triBglLsHn3RuWjNy5Xj2wRw9zl

 

Free study material on MySQL Database in the form of PowerPoint Presentation:

MySQL Database Notes

BASIC CONCEPTS

Data is a collection of raw facts which have not been processed to reveal useful information.

Information is processed data

Example:

Definition of Database

A collection of related data that has been recorded, organized and made available for searching is called a Database.

For example, consider the name, class, roll number, marks in every subject of every student in a school. To record this information about every student in a school, the school might have maintained a register, or stored it on a hard drive using a computer system and software such as a spreadsheet or DBMS package. 

Spreadsheet  v/s DBMS 

Spreadsheet is not organised and automated where as DBMS is automated and more organised. —Searching and updating a record in database is easy and convenient in databases. —Database can be of any size and complexity. 

Why database is needed?

• Data Redundancy: Same information is stored in more than one file. This would result in wastage of space.
• Data Inconsistency: If a file is updated then all the files containing similar information must be updated else it would result in inconsistency of data.
• Lack of Data Integration: As data files are independent, accessing information out of multiple files becomes very difficult.—
• Database approach overcomes these problems 

For example 

—Consider the Sales and Payroll departments of a company. One user will maintain information about all the salespersons in the Sales department in some file say File1 and another user will maintain details about the payroll of the salesperson in a separate file say File2 in the Payroll Department as shown in Figure

Although both the departments need information about the salesperson but they will store information about the salesperson in different files and will use different application programs to access those files.