Question

Sql Server 2005

Table Structure

CREATE TABLE [dbo].[Rate](
[RateID] [bigint] IDENTITY(1,1) NOT NULL,
[PairID] [bigint] NOT NULL,
[Open] [decimal](18, 4) NOT NULL,
[Close] [decimal](18, 4) NOT NULL,
[High] [decimal](18, 4) NOT NULL,
[Low] [decimal](18, 4) NOT NULL,
[Difference] [decimal](18, 4) NOT NULL,
[Average] [decimal](18, 4) NOT NULL,
[Percentage] [decimal](18, 4) NOT NULL,
[InfoDate] [datetime] NOT NULL,
[Hourly] [bit] NOT NULL,
[CaptureDateTime] [datetime] NULL,
CONSTRAINT [PK_Rate] PRIMARY KEY CLUSTERED 
(
[RateID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  =   ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

I am using paging to retrive the table as such

Select  * from(
SELECT
    (ROW_NUMBER()OVER (ORDER BY InfoDate ASC)) AS RowNo,
    [RateID],
    [PairID],
    [Open],
    [Close],
    [High],
    [Low],
    [InfoDate],
    [CaptureDateTime]
From Rate
) AS T
WHERE t.RowNo 
BETWEEN 200*@PageNumber AND 200 * (@PageNumber+1)-1
ORDER BY RowNo DESC

[Question]
I need query which will gives this me table

PageNo, StartIndex(first RateId in that page), EndIndex(Last RateId in that page), StartDate(first infoDate in that page), EndDate(Last infoDate in that page).

Answer 1

You could try to do something like this:

DECLARE @PageSize INT = 200

;WITH PagingInfo AS
(
    SELECT
        RateID, InfoDate,
        ROW_NUMBER() OVER (ORDER BY InfoDate) AS RowNo
    FROM 
        dbo.Rate
),
Pages AS
(
    SELECT     
       RateID,
       InfoDate,
       RowNo,
       ((RowNo - 1) / @PageSize) AS PageNo
    FROM PagingInfo
)
SELECT     
    p.PageNo,
    (SELECT RateID FROM Pages p2 WHERE p2.PageNo = p.PageNo AND p2.RowNo % @PageSize = 1) AS 'First RateID',
    (SELECT RateID FROM Pages p2 WHERE p2.PageNo = p.PageNo AND p2.RowNo % @PageSize = 0) AS 'Last RateID',
    (SELECT InfoDate FROM Pages p2 WHERE p2.PageNo = p.PageNo AND p2.RowNo % @PageSize = 1) AS 'First InfoDate',
    (SELECT InfoDate FROM Pages p2 WHERE p2.PageNo = p.PageNo AND p2.RowNo % @PageSize = 0) AS 'Last InfoDate'
FROM Pages p 
WHERE p.RowNo % @PageSize = 0

The two CTE’s basically do the same as you did – they provide paging for the data. The second CTE Pages additionally provides the page number for each row.

From those CTE’s, I select the relevant into – the page number (from Pages), and the first and last RateID and InfoDate for each page. This works because:

• the first row of every page has a row number that’s 1 above a multiple of your page size, e.g. 1, 201, 401, 601 etc. – so the remainder of an integer division by your page size will always be 1

• the last row of every page has a row number that’s divisible by your page size (e.g. 200, 400, 600 etc. ) and thus the remainder of the integer division is 0

Based on this information, I can pick out the first and last RateID and InfoDate from the Pages CTE, for each page.