What is an Entity Relationship Diagram (ER Diagram)?An ER diagram shows the relationship among entity sets. An entity set is a group of similar entities and these entities can have attributes. In terms of DBMS, an entity is a table or attribute of a table in database, so by showing relationship among tables and their attributes, ER diagram shows the complete logical structure of a database. Lets have a look at a simple ER diagram to understand this concept.A simple ER Diagram:In the following diagram we have two entities Student and College and their relationship. The relationship between Student and College is many to one as a college can have many students however a student cannot study in multiple colleges at the same time. Student entity has attributes such as Stu_Id, Stu_Name & Stu_Addr and College entity has attributes such as Col_ID & Col_Name.

Question

Lalitesh sharma · Accepted Answer

What is an Entity Relationship Diagram (ER Diagram)?An ER diagram shows the relationship among entity sets. An entity set is a group of similar entities and these entities can have attributes. In terms of DBMS, an entity is a table or attribute of a table in database, so by showing relationship among tables and their attributes, ER diagram shows the complete logical structure of a database. Lets have a look at a simple ER diagram to understand this concept.A simple ER Diagram:In the following diagram we have two entities Student and College and their relationship. The relationship between Student and College is many to one as a college can have many students however a student cannot study in multiple colleges at the same time. Student entity has attributes such as Stu_Id, Stu_Name & Stu_Addr and College entity has attributes such as Col_ID & Col_Name.

[An attribute that uniquely identifies each entity in an entity set is called a:]

[Cardinality expresses the number of entity occurrences associated with one occurrence of the related entity]

[An identifier of an entity instance?]

[ A weak entity is one which _____?]

[ The Entity Customer has three candidate keys: a) CustId b) Email and c) ContactNo. Suggest the best primary key for th...

[ Generalization is a bottom-up design process that combines a number of entity sets, which share the same features into...

[Which of the following is another name for weak entity?]

[What is the purpose of an Entity-Relationship (ER) diagram?]

[E-R model uses this symbol to represent weak entity set ?]

[ E-R model uses this symbol to represent weak entity set ?]

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