Write Queries in PostgreSQL, MySQL, SQL Server, Oracle, or SQLite | Crash Course | Beginner | Interview Prepare

What you will learn

Learn how to get started learning SQL

Learn the basic structure of the SQL SELECT statement

Understand how to INSERT, UPDATE, and DELETE data from a table

Learn to write queries to sort, filter, and group data.

Learn how to combine data from two tables using Joins and Subqueries.

Learn SQL in easy to understand English.


Welcome to the EssentialSQL Crash course!  This 7-day course is designed to get you started learning SQL.  I designed it as a seven day course, not because it will take you seven day to complete, but to make it easier for you to digest.  To be honest, work it at any pace you find comfortable.

Here is what we are going to do!

On Day 1, you’ll learn the basics of SQL, including SELECT statements and how to write basic queries. You’ll learn how to select columns and use expressions in your queries. You’ll then have the opportunity to practice what you’ve learned with a set of exercises.

On Day 2, you’ll dive deeper into filtering data with the WHERE clause. You’ll learn about comparison and logical operators and how to use the LIKE operator. You’ll get to apply your newfound skills with a set of practice exercises.

Day 3 is all about sorting data with ORDER BY. You’ll learn how to use the ORDER BY clause and how to sort by multiple columns. You’ll then practice sorting data with a set of exercises.

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On Day 4, you’ll learn how to manipulate data with INSERT, UPDATE, and DELETE statements. You’ll learn how to add, modify, and remove data from tables, and then you’ll practice these skills with exercises.

Day 5 is all about aggregating data with GROUP BY. You’ll learn how to use the GROUP BY clause and how to use aggregate functions like COUNT, SUM, AVG, MIN, and MAX. You’ll then have the opportunity to practice what you’ve learned with a set of exercises.

On Day 6, you’ll learn about joining tables. You’ll learn about the INNER join, and how to join multiple tables. You’ll then practice what you’ve learned with a set of exercises.

Finally, on Day 7, you’ll learn about subqueries. You’ll learn what they are and how to use them in SELECT statements and WHERE clauses. You’ll then get to practice your skills with a set of exercises.

By the end of this course, you’ll be starting to learn SQL and be able to write basic queries, manipulate data, and use cool techniques like grouping and joining.




Relational Databases and Tables
What Version of SQL Should I Use?

Day 1 – Write Your First Query

Learn how to use SELECT
Using Select #1
Using Select #2
Using Select #3

Day 2 – Filter You Query using WHERE

Filter Data using WHERE
Using Comparison Operators
Using LIKE
Using BETWEEN in the WHERE clause
Using the IN comparison Operator

Day 3 – Ordering Results using ORDER BY

Sorting Data using ORDER BY
Using ORDER BY with multiple fields
Getting the Top Items in a Query

Day 4 – Manipulating Data with INSERT, UPDATE, and DELETE

Modifying Data using INSERT, UPDATE, and DELETE

Day 5 – Grouping and Summarizing Query Results

Using GROUP BY to Summarize Your Results
Calculate Averages
Counting Rows

Day 6 – Using INNER JOIN to Combine Data from Multiple Tables

Using INNER JOIN with Two or More Tables
Learn to Write a INNER JOIN
Use a Join and Order the Results
Joining more than Two Tables

Day 7 – Write Subqueries

Write A Subquery to Calculate a Value
Using a Subquery in the SELECT statement
Using a Subquery in an Expression


Bonus Lecture