Posts Tagged with select from

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Resolved: MySQL - Count Number of Unique Values
posted by admin on May 21, 2016
If I have three columns:

orderNumber, name, email

and I would like to count how many unique emails are in the table how would I go about doing so?

A statement like:

SELECT count(email) FROM orders

gives me the total count.
I tried

SELECT DISTINCT count(email) FROM orders

but that does not seem to be giving me the numbers I am expecting.Read more
Resolved: How to get the latest record in each group using GROUP BY?
posted by admin on May 21, 2016
Let's say I have a table called messages with the columns:

id | from_id | to_id | subject | message | timestamp


I want to get the latest message from each user only, like you would see in your FaceBook inbox before you drill down into the actual thread.

This query seems to get me close to the result I need:

SELECT * FROM messages GROUP BY from_id


However the query is giving me the oldest message from each user and not the newest.

I can't figure this one out.Read more