asf

SELECT * FROM Customers WHERE Country = 'Brazil' AND City = 'Rio de Janeiro' AND CustomerID > 50;

sdghdf

- Step 1: Create a table for Departments CREATE TABLE Departments ( DepartmentID INT PRIMARY KEY, DepartmentName VARCHAR(50) NOT NULL ); -- Step 2: Create a table for Employees with a foreign key constraint CREATE TABLE Employees ( EmployeeID INT PRIMARY KEY, FirstName VARCHAR(50) NOT NULL, LastName VARCHAR(50) NOT NULL, Salary DECIMAL(10, 2), DepartmentID INT, HireDate DATE, FOREIGN KEY (DepartmentID) REFERENCES Departments(DepartmentID) ); -- Step 3: Insert initial data into Departments INSERT INTO Departments (DepartmentID, DepartmentName) VALUES (1, 'Engineering'), (2, 'Marketing'), (3, 'Human Resources'); -- Step 4: Insert initial data into Employees INSERT INTO Employees (EmployeeID, FirstName, LastName, Salary, DepartmentID, HireDate) VALUES (101, 'Alice', 'Smith', 85000.00, 1, '2022-03-15'), (102, 'Bob', 'Jones', 60000.00, 2, '2023-01-10'), (103, 'Charlie', 'Brown', 95000.00, 1, '2021-06-01'), (104, 'Diana', 'Prince', 55000.00, 3, '2024-02-20'); -- Step 5: Update an employee's salary (Give Bob a raise) UPDATE Employees SET Salary = 65000.00 WHERE EmployeeID = 102; -- Step 6: Query data by joining both tables to see who works where SELECT E.EmployeeID, E.FirstName, E.LastName, E.Salary, D.DepartmentName FROM Employees E INNER JOIN Departments D ON E.DepartmentID = D.DepartmentID WHERE E.Salary > 60000.00 ORDER BY E.Salary DESC;

asfsa

good

abc

-- 1. DATABASE CREATION & SETUP CREATE DATABASE CompanyDB; USE CompanyDB; -- 2. CREATE TABLE (DDL - Data Definition Language) CREATE TABLE Employees ( EmployeeID INT PRIMARY KEY, FirstName VARCHAR(50) NOT NULL, LastName VARCHAR(50) NOT NULL, Department VARCHAR(50), Salary DECIMAL(10, 2), HireDate DATE ); -- 3. INSERT DATA (DML - Data Manipulation Language) INSERT INTO Employees (EmployeeID, FirstName, LastName, Department, Salary, HireDate) VALUES (101, 'Alice', 'Smith', 'HR', 55000.00, '2022-03-15'), (102, 'Bob', 'Jones', 'IT', 75000.00, '2021-06-20'), (103, 'Charlie', 'Brown', 'IT', 82000.00, '2020-01-10'), (104, 'Diana', 'Prince', 'Marketing', 62000.00, '2023-11-01'), (105, 'Evan', 'Wright', 'Finance', 71000.00, '2019-08-14'); -- 4. BASIC QUERIES (DQL - Data Query Language) -- Retrieve all rows and columns SELECT * FROM Employees; -- Filter results: Find IT employees making more than $80,000 SELECT FirstName, LastName, Salary FROM Employees WHERE Department = 'IT' AND Salary > 80000.00; -- 5. AGGREGATION & SUMMARY -- Calculate total spending and average salary per department SELECT Department, COUNT(EmployeeID) AS TotalEmployees, AVG(Salary) AS AverageSalary FROM Employees GROUP BY Department ORDER BY AverageSalary DESC; -- 6. DATA MAINTENANCE (DML) -- Update an employee's salary UPDATE Employees SET Salary = 65000.00 WHERE EmployeeID = 104; -- Delete an employee record DELETE FROM Employees WHERE EmployeeID = 101;