Complete Solutions by Akshay Gera

.vscode/settings.json

@@ -18,7 +18,6 @@
   "screencastMode.onlyKeyboardShortcuts": true,
   "terminal.integrated.fontSize": 18,
   "window.zoomLevel": 3,
-  "workbench.activityBar.visible": true,
   "workbench.colorTheme": "Default Light+",
   "workbench.fontAliasing": "antialiased",
   "workbench.statusBar.visible": true,

Scripts/SolvedByAkshay/01-01-employees_managers.sql

@@ -0,0 +1,20 @@
+WITH 
+employees_with_managers AS (
+  SELECT 
+    e.employeeId,
+    e.firstName AS EmployeeFirstName,
+    e.lastName AS EmployeeLastName,
+    e.title AS EmployeeTitle,
+    e.startDate AS EmployeeStartDate,
+    e.managerId AS EmployeesManagerID,
+    m.firstName AS ManagerFirstname,
+    m.lastName AS ManagerLastname,
+    m.title AS ManagerTitle,
+    m.startDate AS ManagerStartDate,
+    COALESCE(m.managerId, 'NA') AS ManagersManagerID
+  FROM employee AS e
+  LEFT JOIN employee AS m
+    ON e.managerId = m.employeeId 
+)
+SELECT * FROM employees_with_managers
+ORDER BY employeeId

Scripts/SolvedByAkshay/01-02-salespeople_with_0_sales.sql

@@ -0,0 +1,26 @@
+WITH
+Salespeople AS(
+  SELECT
+    employeeId,
+    firstName,
+    lastName,
+    title,
+    startDate
+  FROM employee
+  WHERE title = 'Sales Person'
+),
+Salespeople_Sales AS (
+  SELECT 
+    e.employeeId,
+    e.firstName,
+    e.lastName,
+    e.title,
+    e.startDate,
+    s.salesAmount 
+  FROM Salespeople AS e
+  LEFT JOIN sales AS s
+    ON e.employeeId = s.employeeId
+)
+SELECT * FROM Salespeople_Sales
+WHERE salesAmount IS NULL
+

Scripts/SolvedByAkshay/01-03-customer_sales.sql

@@ -0,0 +1,19 @@
+WITH 
+Sales_by_customer AS (
+  SELECT
+    customerId,
+    SUM(salesAmount) AS TotalSales
+  FROM sales
+  GROUP BY customerId
+),
+joined AS(
+SELECT
+  *
+FROM customer AS c
+FULL OUTER JOIN Sales_by_customer AS s
+ON c.customerid = s.customerid
+WHERE c.customerId IS NULL OR s.customerId IS NULL
+
+)
+SELECT * FROM joined
+ORDER BY firstName

Scripts/SolvedByAkshay/02-01-cars_sold_by_employee.sql

@@ -0,0 +1,27 @@
+WITH 
+employees AS (
+  SELECT
+    employeeId,
+    firstName,
+    LastName
+  FROM employee
+),
+car_sales AS (
+  SELECT
+    employeeId,
+    COUNT(InventoryID)  AS CarsSold
+  FROM sales
+  GROUP BY employeeId
+),
+sales_by_employees AS (
+  SELECT
+    e.employeeId,
+    e.firstName,
+    e.lastName,
+    s.CarsSold
+  FROM car_sales AS s
+  LEFT JOIN employees AS e
+    ON e.employeeId = s.employeeId
+)
+SELECT * FROM sales_by_employees
+ORDER BY CarsSold DESC

Scripts/SolvedByAkshay/02-02-least_and_most_expensive_car.sql

@@ -0,0 +1,30 @@
+WITH
+Car_Price_By_Salesperson AS (
+SELECT 
+  employeeId, 
+  MAX(salesAmount) AS expensive, 
+  MIN(salesAmount) AS Cheapest 
+FROM sales
+WHERE  date(soldDate) >= '2023-01-01'
+GROUP BY employeeID
+
+),
+Salesperson AS (
+  SELECT
+    employeeId,
+    firstName,
+    lastName
+  FROM employee
+),
+joined AS(
+  SELECT
+    e.employeeId,
+    e.firstName,
+    e.lastName,
+    s.Expensive,
+    s.Cheapest
+  FROM Car_Price_By_Salesperson AS s
+  LEFT JOIN Salesperson AS e
+  ON s.employeeId = e.employeeId
+)
+SELECT * FROM joined

Scripts/SolvedByAkshay/02-03-top_sales_people.sql

@@ -0,0 +1,32 @@
+WITH
+Car_Price_By_Salesperson AS (
+SELECT 
+  employeeId, 
+  COUNT(*) AS CarsSold, 
+  MAX(salesAmount) AS expensive, 
+  MIN(salesAmount) AS Cheapest 
+FROM sales
+WHERE  date(soldDate) >= '2023-01-01'
+GROUP BY employeeID
+HAVING COUNT(*) > 5
+),
+Salesperson AS (
+  SELECT
+    employeeId,
+    firstName,
+    lastName
+  FROM employee
+),
+joined AS(
+  SELECT
+    e.employeeId,
+    e.firstName,
+    e.lastName,
+    s.CarsSold,
+    s.Expensive,
+    s.Cheapest 
+  FROM Car_Price_By_Salesperson AS s
+  LEFT JOIN Salesperson AS e
+  ON s.employeeId = e.employeeId
+)
+SELECT * FROM joined

Scripts/SolvedByAkshay/03-01-sales_per_year.sql

@@ -0,0 +1,9 @@
+WITH
+sales_per_year AS(
+  SELECT
+    strftime('%Y',soldDate) AS Sale_Year,
+    ROUND(SUM(SalesAmount), 2) AS AnnualSales
+  FROM Sales
+  GROUP BY strftime('%Y',soldDate)
+)
+SELECT * FROM sales_per_year

Scripts/SolvedByAkshay/03-02-sales_per_employee_2021.sql

@@ -0,0 +1,43 @@
+WITH
+sales_people AS(
+  SELECT
+    employeeid,
+    firstname,
+    lastname
+  FROM employee
+),
+sales_2021 AS(
+  SELECT
+    employeeId,
+    strftime('%m', soldDate) AS Month,
+    salesAmount AS MonthlySale
+  FROM sales
+  WHERE strftime('%Y', soldDate) = '2021'
+  GROUP BY employeeId, strftime('%m', soldDate)
+),
+sales_pivoted AS(
+  SELECT
+    employeeId,
+    SUM(CASE WHEN month = '01' THEN MonthlySale ELSE 0 END) AS JanSales,
+    SUM(CASE WHEN month = '02' THEN Monthlysale ELSE 0 END) AS FebSales,
+    SUM(CASE WHEN month = '03' THEN Monthlysale ELSE 0 END) AS MarSales,
+    SUM(CASE WHEN month = '04' THEN Monthlysale ELSE 0 END) AS AprSales,
+    SUM(CASE WHEN month = '05' THEN Monthlysale ELSE 0 END) AS MaySales,
+    SUM(CASE WHEN month = '06' THEN Monthlysale ELSE 0 END) AS JunSales,
+    SUM(CASE WHEN month = '07' THEN Monthlysale ELSE 0 END) AS JulSales,
+    SUM(CASE WHEN month = '08' THEN Monthlysale ELSE 0 END) AS AugSales,
+    SUM(CASE WHEN month = '09' THEN Monthlysale ELSE 0 END) AS SepSales,
+    SUM(CASE WHEN month = '10' THEN Monthlysale ELSE 0 END) AS OctSales,
+    SUM(CASE WHEN month = '11' THEN Monthlysale ELSE 0 END) AS NovSales,
+    SUM(CASE WHEN month = '12' THEN Monthlysale ELSE 0 END) AS DecSales
+
+  FROM sales_2021
+
+  GROUP By employeeId 
+
+)
+SELECT e.firstName, e.lastName, s.* FROM sales_pivoted AS s
+LEFT JOIN sales_people AS e
+  ON s.employeeId = e.employeeId
+
+

Scripts/SolvedByAkshay/03-03-electric_car_sales.sql

@@ -0,0 +1,26 @@
+WITH
+electric_models_inventory AS (
+  SELECT 
+    m.modelId,
+    m.model,
+    i.inventoryId 
+  FROM model AS m
+  LEFT JOIN inventory AS i
+    ON m.modelId = i.modelId
+  WHERE m.EngineType = 'Electric'
+),
+electric_model_sales AS(
+  SELECT
+    s.salesId,
+    s.customerId,
+    s.employeeId,
+    s.soldDate,
+    s.inventoryId,
+    m.model,
+    s.salesAmount
+  FROM Sales AS s
+  INNER JOIN electric_models_inventory AS m
+    ON s.inventoryid = m.inventoryId
+
+)
+SELECT * FROM electric_model_sales

Scripts/SolvedByAkshay/04-01-ranking_most_sold_cars.sql

@@ -0,0 +1,31 @@
+WITH
+Sales_by_salesperson AS (
+  SELECT
+    s.employeeId,
+    e.firstName,
+    e.lastName,
+    s.inventoryId,
+    i.modelId,
+    m.model,
+    COUNT(s.inventoryId) AS cars_sold
+  FROM sales AS s
+  LEFT JOIN inventory AS i
+    ON s.inventoryId = i.inventoryId
+  LEFT JOIN model AS m
+    ON i.modelId = m.modelId
+  LEFT JOIN employee AS e
+    ON s.employeeId = e.employeeId
+  GROUP BY e.firstName,
+    e.lastName, i.modelId, m.model
+),
+ranked_sales AS (
+  SELECT
+    firstName,
+    lastName,
+    model,
+    cars_sold,
+    RANK() OVER(PARTITION BY firstName, lastName ORDER BY cars_sold desc) AS Rank
+  FROM sales_by_Salesperson
+
+)
+SELECT * FROM ranked_sales

Scripts/SolvedByAkshay/04-02-sales_per_month.sql

@@ -0,0 +1,18 @@
+WITH
+sales_per_month AS(
+  SELECT
+    strftime('%m', soldDate) AS month,
+    strftime('%Y', soldDate) AS year,
+    SUM(Salesamount) AS monthly_sale
+  FROM Sales
+  GROUP BY strftime('%Y-%m', soldDate)
+)
+SELECT 
+  month,
+  year,
+  monthly_sale,
+  SUM(monthly_sale) OVER(
+    PARTITION BY year 
+    ORDER BY month) AS annual_running_total 
+FROM sales_per_month
+ORDER BY Year,month

Scripts/SolvedByAkshay/04-03-cars_sold_this_month

@@ -0,0 +1,17 @@
+WITH
+sales_per_month AS(
+  SELECT
+    strftime('%m', soldDate) AS month,
+    strftime('%Y', soldDate) AS year,
+    COUNT(*) AS monthly_sale
+  FROM Sales
+  GROUP BY strftime('%Y-%m', soldDate)
+)
+SELECT 
+  month,
+  year,
+  monthly_sale AS current_month_sale,
+  LAG(monthly_sale,1,0) OVER(
+      PARTITION BY year 
+      ORDER BY month) AS last_month_sale 
+FROM sales_per_month