This course introduces basic SQL functions that can be used to process different types of data. It focuses on the most used and most useful standard SQL functions, including:

• SQL text functions.
• SQL numeric functions.
• SQL date and time functions.
• SQL functions dealing with NULL.
• SQL aggregate functions.

In this course, we'll focus on commonly used standard SQL functions. The code we show should work in many SQL databases, although some minor modifications may be needed. However, not all databases comply with the SQL standard. If that's the case, we'll let you know in the exercise instructions.

Many databases offer nonstandard functions which do the same thing as the standard functions we will discuss. We don't have the scope to cover nonstandard syntax in this tutorial; your database's documentation is a good place to learn about any nonstandard syntax it uses.

This course is intended for intermediate users. In order to give you a general idea of what you should already know about SQL, we're going to start with a short review quiz. It will consist of 5 questions with an increasing level of difficulty. We assume you already know how to:

• Query a single table.
• Query multiple tables with JOIN data from multiple tables.
• Sort and group rows.
• Use the HAVING statement.

If you have any questions, feel free to use the DISCUSS tab. Please note that this course has been updated recently, so not all answers to previously asked questions will be suitable now.

So, are you ready?