How to Convert ER Diagrams to Tables in DBMS?
Answer: Converting an ER diagram into tables involves a systematic process starting from table mapping to refining and reviewing.
Step 1: Analyze the Entities
-
Identify each distinct entity in the diagram represented by a rectangle.
-
Examine the attributes associated with each entity which are its characteristics represented by ellipses within the rectangle.
Step 2: Create Separate Tables for Each Entity
- For each entity, create a corresponding table in the database with each attribute as a column in the table.
-
Assign the primary key as a column in the respective table.
Step 3: Map Relationships
- For one-to-many relationships, add a foreign key in the “many” table referencing the “one” table’s primary key.
- For many-to-many, create a linking table with foreign keys to both related tables.
Step 4: Normalize the Tables
- Analyze the tables for redundancies and potential data inconsistencies.
- Apply normalization techniques like decomposition to split tables and eliminate redundancy, improving data integrity and reducing storage space.
Step 5: Verify and Refine
- Review the created tables and relationships for accuracy and efficiency.
- Refine the schema as needed based on further analysis or specific requirements of your database.