For an instructor lead, in-depth look at learning SQL click below.
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Data management is a crucial aspect of all businesses, small and large. Especially when it comes to managing employee expenses. Core to this operation is a Travel Expense Reimbursement System. A well-designed database system offers an efficient way of keeping track of travel expenses and reimbursement of employees in an enterprise.
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System Requirements and Design
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Our database will contain tables for Employees, Expenses, Trips and Reimbursements. We will need to create these tables with the necessary attributes, setup relationships, and enforce integrity constraints. Here’s a basic overview:
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CREATE TABLE Employees ( EmployeeID INT PRIMARY KEY, FirstName VARCHAR(100), LastName VARCHAR(100) ); CREATE TABLE Trips ( TripID INT PRIMARY KEY, EmployeeID INT FOREIGN KEY REFERENCES Employees(EmployeeID), Destination VARCHAR(100), StartDate DATE, EndDate DATE ); CREATE TABLE Expenses ( ExpenseID INT PRIMARY KEY, TripID INT FOREIGN KEY REFERENCES Trips(TripID), Amount DECIMAL(10,2), Category VARCHAR(100) ); CREATE TABLE Reimbursements ( ReimbursementID INT PRIMARY KEY, ExpenseID INT FOREIGN KEY REFERENCES Expenses(ExpenseID), ReimbursementAmount DECIMAL(10,2), ReimbursementDate DATE ); |
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Constructing SQL Queries
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With these tables in place, we can construct SQL queries to add, modify, and retrieve data.
Adding Data:
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-- Adding an employee INSERT INTO Employees (EmployeeID, FirstName, LastName) VALUES (1, 'John', 'Doe'); -- Adding a trip INSERT INTO Trips (TripID, EmployeeID, Destination, StartDate, EndDate) VALUES (1, 1, 'New York', '2021-06-01', '2021-06-05'); -- Adding an expense INSERT INTO Expenses (ExpenseID, TripID, Amount, Category) VALUES (1, 1, 500.00, 'Flight'); -- Adding a reimbursement INSERT INTO Reimbursements (ReimbursementID, ExpenseID, ReimbursementAmount, ReimbursementDate) VALUES (1, 1, 500.00, '2021-06-30'); |
Modifying Data:
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-- Updating an expense amount UPDATE Expenses SET Amount = 550.00 WHERE ExpenseID = 1; -- Updating a reimbursement amount UPDATE Reimbursements SET ReimbursementAmount = 550.00 WHERE ReimbursementID = 1; |
With SQL, you can therefore build a Travel Expense Reimbursement System that is both robust and easy to manage.
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Conclusion
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Through leveraging SQL, you can effectively manage a travel expense reimbursement system with ease, efficiency and accuracy. It simplifies data handling by offering a structured way of storing, retrieving and manipulating data, thus making it an invaluable asset in enterprise settings.