Question

Here’s the dilemma: I have a table with rows. I need to count based on frequency of a certain value (in the eMail column), and then ADD numbers in certain column (cost)… as an example

mail           cost
[e-mail]      10
[e-mail]      5
[e-mail]  3
[e-mail]      7
[e-mail]  2

So I need to group rows based on the email address, and add the numbers in the grouped rows “cost” column. The results should come out as an array:

email          frequency  totalCost
[e-mail]      3          22
[e-mail]  2          5

Answer 1

This can be done with a single SQL query.

SELECT
    email,
    COUNT(email) AS frequency,
    SUM(cost) AS totalCost
FROM
    emails
GROUP BY
    email