Construct an ER diagram for the Banking system in DBMS?


Draw an ER model of the Banking database application considering the following constraints −

  • A bank has many entities.

  • Each customer has multiple accounts.

  • Multiple customers belong to a single branch.

  • Single customer can borrow multiple loans.

  • A branch has multiple employees.


Follow the steps given below to draw an ER model of the Banking database application −

Step 1 − Identify the entity sets

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

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

  • Customer

  • Account

  • Account

  • Loan

  • Loan

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 −

Updated on: 04-Jul-2021

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