Gain insights into SQL by exploring database creation, data manipulation, and advanced queries. Learn about practical applications and practice for SQL interviews to build confidence and readiness.

sql.tar.gz

The ability to work SQL is becoming an increasingly in-demand skill, both for software developers and people in less technical roles. If you’re interested in learning SQL and have no prior experience with it, then this course will be your light in a dark tunnel.

You’ll start by covering the basics of SQL such as how to create a database, how to insert, query, and update data. You’ll also learn fundamental concepts that developers and data scientists use everyday such as multi-table operations, nested queries, and how to set up views. 

Throughout, you’ll get to execute SQL queries in your browser and see results in real-time - you won’t need to worry about set-up.

At the end of this course, you’ll also get some hands-on practice with common SQL interview questions, so when the time comes, you’ll be ready and confident to answer any question that comes your way. Let’s get started!

An Introductory Guide to SQL

Yes. 

NULL is treated as a special value. It is used as a placeholder for unknown or inapplicable values and can't be used with comparison operators such as =, &gt;, &lt;, &lt;&gt;. Therefore the two WHERE clauses aren't equal. NULL should always be tested for using __IS NULL__ or __IS NOT NULL__.

Yes.
NULL is treated as a special value. It is used as a placeholder for unknown or inapplicable values and can’t be used with comparison operators such as =, &gt;, &lt;, &lt;&gt;. Therefore the two WHERE clauses aren’t equal. NULL should always be tested for using IS NULL or IS NOT NULL.

Is there a difference in the results of the following WHERE clauses? 


```mysql
WHERE myColumn = NULL
```

vs.

```mysql
WHERE myColumn IS NULL
```


Is there a difference in the results of the following WHERE clauses?
<pre><code class="language-mysql">WHERE myColumn = NULL
</code></pre>
vs.
<pre><code class="language-mysql">WHERE myColumn IS NULL
</code></pre>

Question # 1

Question # 1

Quiz yourself on MySQL queries and commands, including NULL, indexes, and constraints.

Introduction

Basic SQL

Joins

Nested Queries

Multi Table Operations

Views

Stored Procedures

Triggers

Miscellaneous

Practice & Prep

Epilogue

Quiz 5