E-R Diagram Design

🛠 Step-by-Step Guide to Create E-R Diagram using draw.io:

✅ 1. Open draw.io

• Visit: https://draw.io or https://app.diagrams.net

• Select “Device” or your preferred storage (e.g., Google Drive, OneDrive)
  
  

✅ 2. Create New Diagram

• Click Create New Diagram

• Enter a name (e.g., ER_Diagram_StudentDB)

• Select Blank Diagram (or Entity Relation template if available)

• Click Create
  
  

✅ 3. Use Shapes for E-R Components

In the left sidebar, you’ll find shapes. If not, click "More Shapes" (bottom-left) and enable:

• Entity Relation

• UML

• Database
  
  

Now you’re ready to drag and drop shapes.

✏️ Example Steps:

Suppose you’re creating an ER diagram for Students and Courses:

1. Entities:

   • Drag a Rectangle → name it Student

   • Drag another Rectangle → name it Course
     
     

2. Attributes:

   • Ellipse → StudentID (underline for PK)

   • Ellipse → Name, Email

   • Connect each to the Student entity with lines
     
     

3. Relationship:

   • Diamond → Enrolls

   • Connect Student → Enrolls ← Course

   • If it has attributes (like EnrollmentDate), connect an ellipse to the relationship
     
     

4. Cardinality (Optional):

   • You can label the lines with 1:1, 1:N, or M:N manually using Text tool or use database connectors
     
     

💡 Tips:

• Use Ctrl + D to duplicate shapes quickly

• Use Align and Distribute from the Arrange menu for a clean layout

• Save/export as PNG, PDF, or XML from File > Export As