My table in SQL is like:-
RN Name value1 value2 Timestamp
1 Mark 110 210 20160119
1 Mark 106 205 20160115
1 Mark 103 201 20160112
2 Steve 120 220 20151218
2 Steve 111 210 20151210
2 Steve 104 206 20151203
Desired Output:-
RN Name value1Lag1 value1lag2 value2lag1 value2lag2
1 Mark 4 3 5 4
2 Steve 9 7 10 4
The difference is calculated from the most recent to the second recent and then from second recent to the third recent for RN 1
value1lag1 = 110-106 =4
value1lag2 = 106-103 = 3
value2lag1 = 210-205 = 5
value2lag2 = 205-201 = 4
similarly for other RN's also.
Note: For each RN there are 3 and only 3 rows.
I have tried in several ways by taking help from similar posts but no luck.
I've assumed that RN and Name are linked here. It's a bit messy, but if each RN always has 3 values and you always want to check them in this order, then something like this should work.
SELECT
t1.Name
, AVG(CASE WHEN table_ranked.Rank = 1 THEN table_ranked.value1 ELSE NULL END) - AVG(CASE WHEN table_ranked.Rank = 2 THEN table_ranked.value1 ELSE NULL END) value1Lag1
, AVG(CASE WHEN table_ranked.Rank = 2 THEN table_ranked.value1 ELSE NULL END) - AVG(CASE WHEN table_ranked.Rank = 3 THEN table_ranked.value1 ELSE NULL END) value1Lag2
, AVG(CASE WHEN table_ranked.Rank = 1 THEN table_ranked.value2 ELSE NULL END) - AVG(CASE WHEN table_ranked.Rank = 2 THEN table_ranked.value2 ELSE NULL END) value2Lag1
, AVG(CASE WHEN table_ranked.Rank = 2 THEN table_ranked.value2 ELSE NULL END) - AVG(CASE WHEN table_ranked.Rank = 3 THEN table_ranked.value2 ELSE NULL END) value2Lag2
FROM table t1
INNER JOIN
(
SELECT
t1.Name
, t1.value1
, t1.value2
, COUNT(t2.TimeStamp) Rank
FROM table t1
INNER JOIN table t2
ON t2.name = t1.name
AND t1.TimeStamp <= t2.TimeStamp
GROUP BY t1.Name, t1.value1, t1.value2
) table_ranked
ON table_ranked.Name = t1.Name
GROUP BY t1.Name