An Easy Way To Reference The Nth Row From A Table Meeting A Condition X, And The Mth Row From The Same Table Meeting Condition Y

Hi

I am developing a scientific application (demographic forecasting) and have a situation where I need to update a variety of rows, say the ith, jth and kth row that meets a particular condition, say, x.

I also need to adjust rows, say mth and nth that meet condition , say y.

My current solution is laborious and has to be coded for each condition and has been set up below (If you select this entire piece of code it will create 2 databases, each with a table initialised to change the 2nd,4th,8th and 16th rows, with the first database ignoring the condition and with the second applying the change only to rows with 'type1=1' as the condition.)

This is an adequate solution, but if I want to change the second row meeting a second condition, say 'type1=2', I would need to have another WITH...SELECT...INNER JOIN...UPDATE and I'm sure this would be inefficient.

Would there possibly be a way to introduce a rank by type into the table, something like this added column which increments for each type:







ID
Int1
Type1
Ideal Rank by Type

1
1
1
1

2
1
1
2

3
2
1
3

4
3
1
4

5
5
1
5

6
8
2
1

7
13
1
6

8
21
1
7

9
34
1
8

10
55
2
2

11
89
1
9

12
144
1
10

13
233
1
11

14
377
1
12

15
610
1
13

16
987
2
3

17
1597
1
14

18
2584
1
15

19
4181
1
16

20
6765
1
17

The solution would then be a simple update based on an innerjoin reflecting the condition and rank by type...

I hope this posting is clear, albeit long.

Thanks in advance

Greg

PS The code:

USE

master

GO

CREATE DATABASE CertainRowsToChange

GO

USE CertainRowsToChange

GO

CREATE TABLE InitialisedValues

(

InitialisedValuesID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL

)

GO

CREATE PROCEDURE Initialise

AS

BEGIN

INSERT INTO InitialisedValues (Int1 )

SELECT 2

INSERT INTO InitialisedValues (Int1 )

SELECT 4

INSERT INTO InitialisedValues (Int1 )

SELECT 8

INSERT INTO InitialisedValues (Int1 )

SELECT 16

END

GO

EXEC Initialise

/*=======================================================*/

CREATE TABLE AllRows

(

AllRowsID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL

)

GO

CREATE TABLE RowsToChange

(

RowsToChangeID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL

)

GO

CREATE PROCEDURE InitialiseRowsToChange

AS

BEGIN

INSERT INTO RowsToChange (Int1 )

SELECT 2

INSERT INTO RowsToChange (Int1 )

SELECT 4

INSERT INTO RowsToChange (Int1 )

SELECT 8

INSERT INTO RowsToChange (Int1 )

SELECT 16

END

GO

EXEC InitialiseRowsToChange

GO

CREATE PROCEDURE PopulateAllRows

AS

BEGIN

INSERT INTO AllRows (Int1 )

SELECT 1

INSERT INTO AllRows (Int1 )

SELECT 1

INSERT INTO AllRows (Int1 )

SELECT 2

INSERT INTO AllRows (Int1 )

SELECT 3

INSERT INTO AllRows (Int1 )

SELECT 5

INSERT INTO AllRows (Int1 )

SELECT 8

INSERT INTO AllRows (Int1 )

SELECT 13

INSERT INTO AllRows (Int1 )

SELECT 21

INSERT INTO AllRows (Int1 )

SELECT 34

INSERT INTO AllRows (Int1 )

SELECT 55

INSERT INTO AllRows (Int1 )

SELECT 89

INSERT INTO AllRows (Int1 )

SELECT 144

INSERT INTO AllRows (Int1 )

SELECT 233

INSERT INTO AllRows (Int1 )

SELECT 377

INSERT INTO AllRows (Int1 )

SELECT 610

INSERT INTO AllRows (Int1 )

SELECT 987

INSERT INTO AllRows (Int1 )

SELECT 1597

INSERT INTO AllRows (Int1 )

SELECT 2584

INSERT INTO AllRows (Int1 )

SELECT 4181

INSERT INTO AllRows (Int1 )

SELECT 6765

END

GO

EXEC PopulateAllRows

GO

SELECT * FROM AllRows

GO

WITH Temp(OrigID)

AS

(

SELECT OrigID FROM

(SELECT Row_Number() OVER (ORDER BY AllRowsID Asc ) AS RowScore, AllRowsID AS OrigID, Int1 AS OrigValue FROM Allrows) AS FromTable

INNER JOIN

RowsToChange AS ToTable

ON FromTable.RowScore = ToTable.Int1

)

UPDATE AllRows

SET Int1=1000

FROM

Temp as InTable

JOIN Allrows as OutTable

ON Intable.OrigID = OutTable.AllRowsID

GO

SELECT * FROM AllRows

GO

USE

master

GO

CREATE DATABASE ComplexCertainRowsToChange

GO

USE ComplexCertainRowsToChange

GO

CREATE TABLE InitialisedValues

(

InitialisedValuesID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL

)

GO

CREATE PROCEDURE Initialise

AS

BEGIN

INSERT INTO InitialisedValues (Int1 )

SELECT 2

INSERT INTO InitialisedValues (Int1 )

SELECT 4

INSERT INTO InitialisedValues (Int1 )

SELECT 8

INSERT INTO InitialisedValues (Int1 )

SELECT 16

END

GO

EXEC Initialise

/*=======================================================*/

CREATE TABLE AllRows

(

AllRowsID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL,

Type1 int NOT NULL

)

GO

CREATE TABLE RowsToChange

(

RowsToChangeID int identity(1 ,1) NOT NULL PRIMARY KEY,

Int1 int NOT NULL,

Type1 int NOT NULL

)

GO

CREATE PROCEDURE InitialiseRowsToChange

AS

BEGIN

INSERT INTO RowsToChange (Int1,Type1 )

SELECT 2, 1

INSERT INTO RowsToChange (Int1,Type1 )

SELECT 4, 1

INSERT INTO RowsToChange (Int1,Type1 )

SELECT 8, 1

INSERT INTO RowsToChange (Int1,Type1 )

SELECT 16, 1

END

GO

EXEC InitialiseRowsToChange

GO

CREATE PROCEDURE PopulateAllRows

AS

BEGIN

INSERT INTO AllRows (Int1, Type1 )

SELECT 1, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 1, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 2, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 3, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 5, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 8, 2

INSERT INTO AllRows (Int1, Type1 )

SELECT 13, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 21, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 34, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 55, 2

INSERT INTO AllRows (Int1, Type1 )

SELECT 89, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 144, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 233, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 377, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 610, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 987, 2

INSERT INTO AllRows (Int1, Type1 )

SELECT 1597, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 2584, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 4181, 1

INSERT INTO AllRows (Int1, Type1 )

SELECT 6765, 1

END

GO

EXEC PopulateAllRows

GO

SELECT * FROM AllRows

GO

WITH Temp(OrigID)

AS

(

SELECT OrigID FROM

(SELECT Row_Number() OVER (ORDER BY AllRowsID Asc ) AS RowScore, AllRowsID AS OrigID, Int1 AS OrigValue FROM Allrows WHERE Type1=1) AS FromTable

INNER JOIN

RowsToChange AS ToTable

ON FromTable.RowScore = ToTable.Int1

)

UPDATE AllRows

SET Int1=1000

FROM

Temp as InTable

JOIN Allrows as OutTable

ON Intable.OrigID = OutTable.AllRowsID

GO

SELECT * FROM AllRows

GO