I'm trying to do something similar to Select the 3 most recent records where the values of one column are distinct, but with a count, which means I need to preserve the group.
Using the same example:
id time text otheridentifier
-------------------------------------------
1 6 apple 4
2 7 orange 4
3 8 banana 3
4 9 pear 3
5 10 grape 2
SELECT *, COUNT(*) FROM `table` GROUP BY (`otheridentifier`) ORDER BY `time` DESC LIMIT 3
would return id of 5, 3, 1 with the proper counts, but I want 5, 4, 2.
The solution in that post was
SELECT * FROM 'table' WHERE 'id' = (SELECT 'id'
FROM 'table' as 'alt'
WHERE 'alt'.'otheridentifier' = 'table'.'otheridentifier'
ORDER BY 'time' DESC
LIMIT 1) ORDER BY 'time' DESC LIMIT 3
but I don't see how to grab a count, sinc开发者_运维知识库e I need a grouping there: I get ERROR 1140 (42000): Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause
if I add COUNT(*) to the beginning of that.
SELECT *, COUNT(*)
FROM `table`
GROUP BY (`otheridentifier`)
ORDER BY COUNT(*) DESC LIMIT 3
^^^^^^^^^^^^^^^^^
simply change the order-by clause. ordering is done after the grouping/aggregating is completed, so you can sort by the results of those aggregate functions.
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