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
don't you have the notes in pdf format so i can download
ReplyDeleteSorry but I am not having database notes right now
Delete