This page contains information of Library Management System database design. The database in turn is further described in detail giving all the fields used with the data types, constraints available, primary key and foreign key.
What is a database management system :
Database design is used to manage large of information. The database is a collection of information and is systematically stored in tables in the form of rows and columns. The table in the database has unique name that identifies its contents. In this database we describe the entire 4 table available in the software, which are used to store all the records.
2. Data types and its description:
Fields in database table have a data type used in database table are explained below.
- Integer: one optional sign character (+ or -) followed by at least one digit (0-9). Leading and trailing blanks are ignored. No other character is allowed.
- Varchar: It is used to store alpha numeric characters. In this data type we can set the maximum number of characters up to 8000 ranges by defaults SQL server will set the size to 50 characters range.
- Data/time: Data/time data type is used for representing date or time.
Entity Relationship Diagram:
Entity Relationship Diagram is used in modern database software engineering to illustrate logical structure of database. It is a relational schema database modeling method used to
Model a system and approach. This approach commonly used in database design. The diagram created using this method is called ER-diagram.
The ER-diagram depicts the various relationships among entities, considering each object as entity. Entity is represented as rectangle shape and relationship represented as diamond shape. It depicts the relationship between data object. The ER-diagram is the notation that is used to conduct the data modeling activity.
Entity: Entity is the things which we want to store information. It is an elementary basic building block of storing information about business process. An entity represents an object defined within the information system about which you want to store information. Entities are distinct things in the enterprise.
Relationship: A relationship is normal connection or association between entities used to relate two or more entities with some common attributes or meaningful interaction between the object.
Attributes: Attributes are the properties of the entities and relationship descriptor of the entity. Attributes are elementary pieces of information attached to an entity.