# Aggregation

* `COUNT (column)`
* `SUM (column)`
* `MIN & MAX`
* `LEAST & GREATEST`
* `AVG`

## `count`

```sql
SELECT COUNT(DISTINCT (movie_lang))
from movies;

 count 
-------
     8

-- with where clause

SELECT COUNT(movie_lang)
FROM movies
where movie_lang = 'English';

 count 
-------
    38
```

## Sum

```sql
select sum(revenues_domestic)
from movies_revenues;

  sum   
--------
 5719.5

select SUM(revenues_domestic::numeric)
from movies_revenues
where revenues_domestic::numeric > 200;

  sum   
--------
 3425.6

SELECT SUM(DISTINCT revenues_domestic)
FROM movies_revenues;

  sum   
--------
 5708.4
```

## Min and Max

```sql
SELECT min(movie_length), MAX(movie_length)
FROM movies

 min | max 
-----+-----
  87 | 168
```

## Average, Greatest, Latest

```sql
SELECT GREATEST(10, 20, 30, 40), LEAST(10, 20, 30, 40);

 greatest | least
----------+-------
       40 |    10

SELECT GREATEST('A', 'B', 'C', 'D'), LEAST('A', 'B', 'C', 'D');

 greatest | least
----------+-------
 D        | A

SELECT GREATEST('A', 'B', 'C', 1);

-- ERROR:  invalid input syntax for type integer: "A"
-- LINE 1: SELECT GREATEST('A', 'B', 'C', 1);

SELECT AVG(movie_length)
FROM movies;

         avg          
----------------------
 126.1320754716981132
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://dev117uday.gitbook.io/databases/sql/tables/aggregation.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.