In this table I store changeable values for certain spids. As days go by, these values can change, and an spid can get a new value.
Now I want to find out until when a certain value is enabled.
This is the data for a single spids
uid spid propertyvalue creationdate
--------------------------------------------------
1 3 First name 2010-01-17 22:34:00
37 3 Second name 2010-01-18 01:07:24
38 3 Third name 2010-01-18 01:09:00
39 3 Fourth name 2010-01-18 01:18:16
40 3 Fifth name 2010-01-18 01:20:02
So the first value starts at 2010-01-18 01:07:24 and would be valid until 2010-01-18 01:01:00.
I already tried this query:
SELECT s1 . * ,
s2.creationdate AS datetwo
FROM salespointproperty s1
JOIN salespointproperty s2 ON s1.spid = s2.spid
AND s1.creationdate < s2.creationdate
That gives me a lot of double-records (some of them wrong), and it always leaves out the last new name (as it doesn't have a new creationdate following it) Example:
uid spid propertyvalue creationdate datetwo
--------------------------------------------------------------
1 3 First name 2010-01-17 22:34:00 2010-01-18 01:07:24 *
1 3 First name 2010-01-17 22:34:00 2010-01-18 01:09:00
37 3 Second name 2010-01-18 01:07:24 2010-01-18 01:09:00 *
1 3 First name 2010-01-17 22:34:00 2010-01-18 01:18:16
37 3 Second name 2010-01-18 01:07:24 2010-01-18 01:18:16
38 3 Third name 2010-01-18 01:09:00 2010-01-18 01:18:16 *
1 3 First name 2010-01-17 22:34:00 2010-01-18 01:20:02
37 3 Second name 2010-01-18 01:07:24 2010-01-18 01:20:02
38 3 Third name 2010-01-18 01:09:00 2010-01-18 01:20:02
39 3 Fourth name 2010-01-18 01:18:16 2010-01-18 01:20:02 *
Only the lines with an asterix are correct. The fifth name is missing.