Database Approach
A database is a shared collection of records.
Back end:
Collection of tables/ relations that stores database.
Front End:
Forms which is to be filled by the user is the front end.
Advantages of Database Approach:
- Program data Independence.
- Planned data Redundancy.
- Improved data Consistency.
- improved data Sharing.
- Increase Programmer Productivity
- Enhanced enforcement of data standards
- Improved Data Quality
- Improved Data Accessibility
- Reduced Program Maintenance
ERD (Entity Relational Diagram)
An entity relationship model, also called an entity-relationship (ER) diagram, is a graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems. An entity is a piece of data-an object or concept about which data is stored.
- 1:1 one-to-one
In this type of diagram one entity has relation with only one type of entity. For example one doctor 'check' one patient at a time. It is Denoted by straight lines.
- 1:M one-to-many
It is another type of ER Diagram, An entity on one side of the relationship can have many related entities, but an entity on the other side will have a maximum of one related entity For example one headmaster 'manages' many teachers in an institution. One side it is denoted by one straight line and on the other side of three lines.
- M:M many-to-many
It is another ER Diagram in which many entities have a relation with many other relations. For example many students 'lives in' many rooms.Both sides are denoted by three lines.
Entity, Attributes and Relationship NEXT
Entity, Attributes and Relationship NEXT
Written by Faraz
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