SQL for Product Managers

FROM BASICS TO INTERMEDIATE LEVEL

Why SQL is needed for Product Managers?

Product managers sets an objective and fixes a success criteria while monitoring metrics or KPIs(Key-Performance-Indicators).

If you are a Product Manager, SQL will help you:

1. Monitoring Metrics & KPIs
2. Maked a PM more independent
3. Improves the knowledge about the Product

What is SQL?

Structured Query Language is used for RDBMS(Relational Database Management System).

Database contains tables and schemas which are linked through Primary Key & Foreign Keys.

E-R Diagram, Primary-Key and Foreign-Key

Example for Entity-Relational-Diagram

Source: Arctype

Primary Key refers to a key or a column which should:

• Have a Unique ID
• Value cannot be Null

Foreign Key refers to the key which is present into other table(mainly in terms of primary key of another table).

Where in Orders Table, primary key is orderID and foreign keys are customerID, employeeID and productID, have a relation of Orders Table with Customers Table, Employees Table and Products Table.

Types of Commands

There are 5 types of SQL Commands:

1. DDL(Data Definition Language)
2. DML(Data Manipulation Language)
3. TCL(Transaction Control Language)
4. DQL(Data Query Language)
5. DCL(Data Control Language)

SQL Commands

Source: GFG (GeeksForGeeks)

Usually, Product Managers need mainly SELECT command for the fetching-out the data and analyzing the data-metrics.

Now, Let’s suppose that we have a Customer Table.

Phase 01: SELECT | WHERE | ORDER BY

Let’s Call-out the table with the whole columns!

1. Show the Customer Table:

SELECT*FROM Customers;

Result:

2. Fetch the name of customers who stay in Germany:

SELECT CustomerName 
FROM Customers
WHERE Country = "Germany";

Result:

Customers with having Country = “Germany”

3. Select Customers’ name, City. WHERE Country is “Germany”, and sort the result alphabetically by the column City.

SELECT CustomerName, City
FROM Customers
WHERE Country = "Germany"
ORDER BY City;

Result:

Phase 02: MAX | MIN | AVG | SUM | COUNT

Now, let’s suppose that we have a Products Table

PRODUCTS TABLE

Give us the ProductID, ProductName which have maximum, minimum and average price of products in Products Table:

Maximum Product Price

SELECT ProductID, ProductName, MAX(PRICE)
FROM Products; 

Result:

Minimum Product Price

SELECT ProductID, ProductName, MIN(PRICE)
FROM Products;

Result:

Now, we can calculate the Profits(Use-cases).

Average Product Price

SELECT AVG(PRICE)
FROM PRODUCTS;

Result:

SUM of Products’ Prices

SELECT SUM(Price) FROM Products;

Result:

COUNT of Products:

SELECT COUNT(*) FROM Products;

Result:

Phase 03: WILDCARDS(Like) | IN | BETWEEN

WILDCARDS

Source: W3SCHOOLS.COM

IN Operator

Let’s again consider Customers Table

SELECT * FROM Customers
WHERE Country IN ('Germany', 'France', 'UK');

Result

NOT IN Operator

SELECT * FROM Customers
WHERE Country NOT IN ('Germany', 'France', 'UK');

Result:

BETWEEN Operator

SELECT * FROM Products
WHERE Price NOT BETWEEN 10 AND 20;

Phase 04: JOINS | INNER | OUTER | LEFT | RIGHT

SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
FROM Orders
INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID;

Result:

Above example depicted INNER JOIN only.

So, there are various types of JOINS:

Types of JOINS

Source: W3SCHOOLS.COM

Thank-you 😁