Introduction To Database Flashcards
It is a Collection of information that is organize
Database
Give some example of commonly used database
•Address book
•Library catalogue
•Telephone directory
•Stock list
Give some example of the sort of information that can be kept in a database
•Inventory Control
•Payroll system
•Personnel
Give some of the popular relational database management system
•Microsoft access
•File Maker
•mySQL
•Oracle
•Microsoft mySQL server
Advantages of database
•Improved Availability
•Minimized Redundancy
•Accuracy
•Program and file consistency
•User friendly
•Improved Security
It is responsible for strong data in the database,
Database tables cnsists of rows (record) and columns (fields)
Table
It is a named of unit of information
Field
A discrete piece of information that is part of a record
Field
It is a group of fields within a table that are relevant to a specific entity
Record
A row in a table that contains information about a particular person, place or thing
Record
Relational Database
> The Primary key
The Foreign key
It is a field that uniquely Identifies the record
Primary Key
It is a field in a relational table that matches the primary key column of another table. Can be used to cross reference tables.
Foreign Key
It Identifies a column or a set of column in one(referencing) table that refers to a column or set of columns in another (referenced) table.
Foreign key
It is the process of organizing data to minimize duplication
Normalization
All columns (field) must be atomic which mean no repeating items in column.
First Normal Form
All non-key columns must be fully dependent on the primary key.
Second Normal Form
A table must meet all the requirements for first and second normal forms. and all non key column must be mutually independent.
Third Normal Form
Database Relationship
> One to One Relationship
One to many relationship
Many to many relationship
It can exist between any two tables in which a row in the first table can be related to only one row in the second table and a row in the second table can be related only row in first table.
One to One relationship
This Relationship cannot directly define a many to many relationship access. The user must be develop this type of relationship by adding a table called JUNCTION TABLE.
Many to Many relationship
It Differs from one to one relationship in that a row in the first table can be related to one or more rows in the second table, but a row in the second table can be related to only one row in the first table
One to Many relationship
