Construct an ER diagram for the Banking system in DBMS?

The entity set has multiple instances in a given business scenario.

As per the given constraints the entity sets are as follows −

Step 2 − Identify the attributes for the given entities

• Customer − the relevant attributes are customerName, CustomerID, address.
• Account − The relevant attributes are AccountNo, balance.
• Branch − The relevant attributes are branchID, branchName, address.
• Loan − The relevant attributes are loanNo, paymentMode, dateOfLoan, and amount.
• Employee − The relevant attributes are empID, empName, dateOfJoin, experience, qualification.

Step 3 − Identify the Key attributes

• CustomerID is the key attribute for a customer.
• AccountNo is the key attribute for Account entities.
• BranchID is the key attribute for branch entities.
• LoanNo is the key attribute for a loan entity.
• EmpID is the key attribute for an Employee entity.

Step 4 − Identify the relationship between entity sets

• One customer is enrolled by multiple accounts and one account for multiple customers. Hence, the relationship is many to many.

• Many customers belong to one branch but one branch belongs to many customers. Hence, the relationship between customer and branch is many to one.

• One customer can borrow multiple loans in the same way multiple loans can borrow a single customer, hence the relationship between customer and loan is one to many.

• One branch has many employees and in the same way the number of employees works in a single branch.

Step 5 − Complete ER diagram

The complete ER diagram is as follows −