Query to find the difference between the last date and the second to the last date

Question

Hi all,
Hope all is well.
I am working on the following problem because I am trying to improve my MS SQL skills. But I am stuck at the moment and I wonder if you could provide some assistance please. Here is the issue:
Table 1: Dividends
divId
ExDate
RecordDate
PayDate
Amount
Yield
symId
1
2013-02-19
2013-02-21
2013-03-14
0.23
0.00000
3930
2
2012-11-13
2012-11-15
2012-12-13
0.23
0.00849
3930
3
2012-08-14
2012-08-16
2012-09-13
0.20
0.00664
3930
4
2012-05-15
2012-05-17
2012-06-14
0.20
0.00662
3930
5
2012-02-14
2012-02-16
2012-03-08
0.20
0.00661
3930
6
2011-11-15
2011-11-17
2011-12-08
0.20
0.00748
3930
7
2011-08-16
2011-08-18
2011-09-08
0.16
0.00631
3930
8
2011-05-17
2011-05-19
2011-06-09
0.16
0.00653
3930
9
2011-02-15
2011-02-17
2011-03-10
0.16
0.00594
3930
10
2010-11-16
2010-11-18
2010-12-09
0.16
0.00620
3930
11
2010-08-17
2010-08-19
2010-09-09
0.13
0.00526
3930
12
2010-05-18
2010-05-20
2010-06-10
0.13
0.00455
3930
13
2010-02-16
2010-02-18
2010-03-11
0.13
0.00459
3930
Table 2: Tickers
symId
Symbol
Name
Sector
Industry
1
A
Agilent Technologies Inc.
Technology
Scientific & Technical Instruments
2
AA
Alcoa, Inc.
Basic Materials
Aluminum
3
AACC
Asset Acceptance Capital Corp.
Financial
Credit Services
4
AADR
WCM/BNY Mellon Focused Growth ADR ETF
Financial
Exchange Traded Fund
5
AAIT
iShares MSCI AC Asia Information Tech
Financial
Exchange Traded Fund
6
AAME
Atlantic American Corp.
Financial
Life Insurance
7
AAN
Aaron's, Inc.
Services
Rental & Leasing Services
8
AAON
AAON Inc.
Industrial Goods
General Building Materials
9
AAP
Advance Auto Parts Inc.
Services
Auto Parts Stores
10
AAPL
Apple Inc.
Technology
Personal Computers
11
AAT
American Assets Trust, Inc.
Financial
REIT - Office
12
AAU
Almaden Minerals Ltd.
Basic Materials
Industrial Metals & Minerals
I am trying to check the last date (i.e. max date) and also check the penultimate date (i.e. the second to the last date).  And then find the difference between the two (i.e. last date minus penultimate
date).
I would like to do that for each of the companies listed in Table 2: Tickers.  I am able to do it for just one company (MSFT) using the queries below:
SELECT
[First] = MIN(ExDate),
[Last] = MAX(ExDate),
[Diff] = DATEDIFF(DAY, MIN(ExDate), MAX(ExDate))
FROM (
SELECT TOP 2 Dividends.ExDate
FROM Dividends, Tickers
WHERE Dividends.symId=Tickers.symId
AND Tickers.Symbol='MSFT'
ORDER BY ExDate DESC
) AS X
Outputs the following result:
First
Last
Diff
2012-11-13
2013-02-19
98
But what I would like instead is to be able to output something like this:
Symbol
First
Last
Diff
MSFT
2012-11-13
2013-02-19
98
AAN
2012-11-13
2012-12-14
1
X
2012-11-13
2012-12-14
1
Can anyone please let me know what do I need to add on my query in order to achieve the desired output?
Any help would be greatly appreciated.
Thanks in advance. 

Answer 1

Could you try this?
create table Ticker (SymbolId int identity primary key, Symbol varchar(4))
insert into Ticker (Symbol) values ('MSFT'), ('ORCL'), ('GOOG')
create table Dividend (DividendId int identity, SymbolId int constraint FK_Dividend foreign key references Ticker(SymbolId), ExDate datetime, Amount decimal(18,4))
insert into Dividend (SymbolId, ExDate, Amount) values
(1, '2012-10-1', 10),
(1, '2012-10-3', 1),
(1, '2012-10-7', 7),
(1, '2012-10-12', 2),
(1, '2012-10-23', 8),
(1, '2012-10-30', 5),
(2, '2012-10-1', 10),
(2, '2012-10-6', 1),
(2, '2012-10-29', 7),
(3, '2012-10-1', 22),
(3, '2012-10-3', 21),
(3, '2012-10-7', 3),
(3, '2012-10-12', 9)
WITH cte
AS (SELECT t.Symbol,
d.ExDate,
d.Amount,
ROW_NUMBER()
OVER (
partition BY Symbol
ORDER BY ExDate DESC) AS rownum
FROM Ticker AS t
INNER JOIN Dividend AS d
ON t.SymbolId = d.SymbolId),
ctedate
AS (SELECT Symbol,
[1] AS maxdate,
[2] AS penultimatedate
FROM cte
PIVOT( MIN(ExDate)
FOR RowNum IN ([1],
[2]) ) AS pvtquery),
cteamount
AS (SELECT Symbol,
[1] AS maxdateamount,
[2] AS penultimatedateamount
FROM cte
PIVOT( MIN(Amount)
FOR RowNum IN ([1],
[2]) ) AS pvtquery)
SELECT d.Symbol,
MIN(MaxDate) AS maxdate,
MIN(penultimatedate) AS penultimatedate,
DATEDIFF(d, MIN(penultimatedate), MIN(MaxDate)) AS numberofdays,
MIN(MaxDateAmount) AS maxdateamount,
MIN(penultimatedateAmount) AS penultimatedateamount,
MIN(MaxDateAmount) - MIN(penultimatedateAmount) AS delta
FROM ctedate AS d
INNER JOIN cteamount AS a
ON d.Symbol = a.symbol
GROUP BY d.Symbol
ORDER BY d.Symbol
Please mark this reply as the answer or vote as helpful, as appropriate, to make it useful for other readers.
Thanks!
Aalam | Blog (http://aalamrangi.wordpress.com)