SQLite SUM

Summary: in this tutorial, you will learn how to use the SQLite SUM function to calculate the sum of all values.

Introduction to SQLite SUM function

The SUM function is an aggregate function that returns the sum the non-NULL values or only the distinct values in a group.

The following expression illustrates the syntax of the SUM function:

SUM([ALL | DISTINCT] expression);

The SUM function uses ALL clause by default. It means that all the input values, whether duplicate or not, are considered when the SUM function performs the calculation.

If you want to calculate the sum of unique values, you have to specify the  DISTINCT clause explicitly in the expression.

The result of the SUM function is an integer if all input non-NULL values are integers. If any input value is neither an integer nor a NULL value, the result of the SUM function is a floating-point value.

The result of the SUM function is NULL if and only if all input values are NULL.

In case there is an integer overflow error happens and all input values are NULL or integers, the SUM function throws an integer overflow exception.

SQLite SUM function examples

We will use the tracks table in the sample database for the demonstration.

To get the total length of all tracks in the tracks table, you use the SUM function as the following statement:

SELECT
   SUM(milliseconds)
FROM
   tracks;

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SQLite SUM function with GROUP BY clause

To calculate the total length of each album, you need to use the SUM function with the  GROUP BY clause.

First, the GROUP BY clause groups a set of tracks by albums. Then, the SUM function calculates the sum of lengths of tracks per album.

The following statement illustrates the idea:

SELECT
   AlbumId,
   SUM(milliseconds)
FROM
   tracks
GROUP BY
   AlbumId;

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SQLite SUM function and INNER JOIN clause example

To include the album titles in the output, you join the tracks table to the albums table using the  INNER JOIN clause as follows:

SELECT
   tracks.albumid,
   title, 
   SUM(milliseconds)
FROM
   tracks
INNER JOIN albums ON albums.albumid = tracks.albumid
GROUP BY
   tracks.albumid, 
   title;

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SQLite SUM function and HAVING clause example

You can use the SUM function in the  HAVING clause to filter groups based on a specified condition.

For example, the following statement gets all albums whose total lengths are greater than 1,000,000 milliseconds:

SELECT
   tracks.albumid AlbumId,
   Title,
   SUM(milliseconds)
FROM
   tracks
INNER JOIN albums ON albums.albumid= tracks.albumid
GROUP BY
   tracks.albumid, 
   title
HAVING
	SUM(milliseconds) > 1000000;

Try It

In this tutorial, we have introduced you to the SQLite SUM function that returns the sum of values in a group.