Question

I’m atm seeing a strange behaviour in a sql request.

My table pointLog:

# Column Type
1 date timestamp
2 uid varchar(30)
3 ssid varchar(40)
4 reason varchar(50)
5 points int(5) No None

The statement:

SELECT date, count(date) as anzahl FROM pointLog WHERE uid = 1 order by date desc 

returns following result

    date                anzahl
2012-09-01 12:21:16     14

But the statement:

SELECT date FROM pointLog WHERE uid = 1 order by date desc 

Returns

2012-09-02 12:44:08

as first result.

So my question: why I’m not receiving the 2012-09-02 as first result in the first statement which includes a count ??

Thanks a lot!

edit
The count as anzahl is atm only used to verify that there are more than 0 entries in this example. I know its should be tested in the programm.

But my main problem is, that I can’t explain, why I’m getting 2 different dates when it’s sorted by the same (date). So the only difference is the count attribute. But that shouldn’t normally change the sorting?

FINAL* The solution

SELECT MAX(date) AS maxdate, COUNT(date) AS anzahl FROM pointLog WHERE uid = 1

Answer 1

As @prosfilaes answered, your query does not return deterministic results, the date returned in an arbitrary one.

If you want the latest date and the count, you can use:

SELECT 
    MAX(date) AS maxdate, 
    COUNT(date) AS anzahl 
FROM 
    pointLog 
WHERE 
    uid = 1 ;