Wednesday, March 6, 2013

DBMS



Data: Unprocessed information (Row facts and figure).

Information: Processed Data.

Data
Information
Naveen
Dau
Nirmal
Jyoti
Jyoti
Naveen
Dau
Nirmal
Priya
Priya

Database: Collection of data in interrelated manner.

Keys:

Primary key:
It will be unique in table. Like – University enrolment number.

Foreign key:
A primary key of a table used as a reference key in another table called foreign key.

Composite key:
It is clear that composite means combination of multiple information. If we want to define area then it will distinguish in multiple attributes like street.

Unique key:
It will also be unique but not primary. In this if information will not filled then bloke will be null but in primary key it can’t be null.

SQL Operations:
1.     Create Database
2.     Select Database
3.     Insert Command
4.     Delete Command
5.     Update Command

2 comments:

  1. don't you have the notes in pdf format so i can download

    ReplyDelete
    Replies
    1. Sorry but I am not having database notes right now

      Delete

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