Aggregate functions

  1. Counting
  2. Largest value
  3. Smallest value
  4. Average value
  5. Total sum

Opis Database provides support for most common and widely used aggregate functions.

Counting

Counting records is done using the count method.

$count = $db->from('users')->count();

echo 'There are ' . $count . ' users registred on this site.';
SELECT COUNT(*) FROM `users`

Counting all values(NULL values will not be counted) of a column is done by passing the column’s name as an argument to the count method.

$count = $db->from('users')->count('description');

echo 'There are ' . $count . ' users that have provided a description for their profile.';
SELECT COUNT(DISTINCT `country`) FROM `users`

Largest value

Finding the largest value of a column is done using the max method. This method accepts the column’s name as an argument.

$count = $db->from('users')->max('age');

echo 'Our oldest user is ' . $count . ' years old.';
SELECT MAX(`age`) FROM `users`

Smallest value

Finding the smallest value of a column is done using the min method. This method accepts the column’s name as an argument.

$count = $db->from('users')->min('age');

echo 'Our youngest user is ' . $count . ' years old.';
SELECT MIN(`age`) FROM `users`

Average value

Finding the average value of a numeric column is done using the avg method. This method accepts the column’s name as an argument.

$count = $db->from('users')->avg('age');

echo 'The average age of our users is ' . $count . ' years.';
SELECT AVG(`age`) FROM `users`

Total sum

Finding the total sum of a numeric column is done using the sum method. This method accepts the column’s name as an argument.

$count = $db->from('users')->sum('age');

echo 'Our users gathered together ' . $count . ' years of life experience.';
SELECT SUM(`age`) FROM `users`