Similar to the previous chapter, **SUM**, **AVG**, and **COUNT** functions are aggregate functions that return the sum of field, average value, and count. **SUM** and **AVG** can be applied only for numbers, and **COUNT** - for fields of any data type.

If you want to find the number of records with some condition, you can apply **COUNT** to the *.

This query outputs the number of records with the release date in the 20th century:

SELECT COUNT(*) FROM songs
WHERE year <= 2000

## Aggregate functions and Distinct

If you want to apply aggregate function to the unique values, write **DISTINCT** inside this function and before the column name:

This course was created for very beginners in programming, for those who want to start learning such a popular language for work with databases. Nowadays, all the applications and services collect some data and work with it, and basic SQL syntax is a foundation for further work with other Database Management Systems.

Familiarize yourself with database you will work with, and basic syntax to start executing your first queries!

SQL Count, Sum, Avg

Aggregate functions and Distinct

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