What is the process of creating an ER Diagram?

Process of creating ER Diagram

Gathering Requirments:

The process of collecting all the required information is usually achieved through dialogues and interviews with stakeholders to determine the problem, scope, and requirements of the system being designed.There are specific methods to follow for gathering requirements, which are outlined below.

1. Interviews with stakeholders and end user
2. Document Analysis
3. Use case Identification 
4. Lead workshop and meeting with stakeholders
5. Research and study about the main object
6. Review and validation

Identify entities:

This process begins with a general idea, followed by brainstorming, and continues through to the final draft, which is a crucial action. Entities are the main components and primary objects that help specify the system. Generally, entities are considered nouns. For example, In a hospital database entities could be Doctor, Patient, and Nurse.

Understand and define relationship:

Building relationships between entities in an ER diagram is essential for developing a comprehensive, efficient, and reliable database system. This process ensures data integrity, simplifies complex data relationships, enhances data analysis, Supporting Complex Queries, reduces redundancy and enhances overall database functionality.

A doctor prescribes medication for the patient..

Determine attributes:  Identify the characteristics of an entity and define them clearly, ensuring that the details of each attribute are associated with the object.

Specify cardinality:

The cardinality of relationships describes the numerical relationship between entities. one-to-one, one-to-many, and many-tomany

Symbols on the relationship lines demonstrate the type of relationship:

• A single line (|) for one.
• A crow’s foot (three lines ) for many.

Draw diagram:

The ER diagram can be created once the system entities are finalized, entity attributions are established, and entity relationships are determined.Now, demonstrate the required system diagram using a diagramming tool such as Microsoft Visio, Lucidchart, or even pen and paper. Entities are represented by rectangles. Attributes are represented by ovals, connected with the respective entities. Relationships are represented by diamonds, attached to the relevant entities. Indicate cardinality with symbols such as crows-feet or single lines.

Review and verify the diagram: 

The diagram needs to be reviewed and refined with stakeholders to ensure it accurately represents the system requirements.

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