Computation And Promutation
Feb 1, 2004i am trying to set up a quick and dirty, but efficient way to calculate permutation and combination. anyone out there dealt with this?
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Checksum Computation Help
Feb 6, 2004Please execute the script below to understand the problem -
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create table test(id int, col1 int,col2 varchar(5),col3 datetime)
create table test2(id int, col1 int,col2 varchar(5),col3 datetime)
--id & col1 make up the PK.
insert test values(4,4,'d','02/06/2004')
insert test values(4,4,'e','02/06/2004')
insert test2 values(4,4,'d','02/06/2004')
insert test2 values(4,4,'e','02/06/2004')
select *
from test
select *
from test2
--The rows are identical.
--Script A
select t.*
from test t
join test2 t2 on t2.id=t.id
where CHECKSUM(t.col2,t.col3)<>CHECKSUM(t2.col2,t2.col3)
--The purpose of the above script is to check for any updates in the two tables. It returns two rows. But as you can see both these rows were present in the table before. So I modify the script to -
--SCRIPT B
select t.*
from test t
join test2 t2 on t2.col2=t.col2
where CHECKSUM(t.col3)<>CHECKSUM(t2.col3)
-- In this case no row is returned.This is exactly what I need. The problem - Now execute the script below.
TRUNCATE TABLE TEST
TRUNCATE TABLE TEST2
insert test values(4,4,'d','02/06/2004')
insert test values(4,4,'d','02/01/2004')
insert test2 values(4,4,'d','02/06/2004')
insert test2 values(4,4,'d','02/01/2004')
--Now when I execute script B two rows are returned which is not what I want. Since the rows are identical no row should be returned. So depending on what column changes (col2 or col3), I have to alter the script. I seek advise on the method to calculate checksum. Again the PK is ID and Col1 only.
Thanks
drop table test
drop table test2
go
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Mathematical Computation In Transact SQL
Mar 5, 2008What is the equivalent in Transact SQL for VB.net ^ (Exponent Operator)
I have a following equation in VB.net
DotGain = ((1 - 10 ^(D0 - D50)) /(1 - 10 ^ (D0 - D100))) * 100 - 50
where D0, D50 and D100 are decimal variables
Working on creating a SQL UDF where @D0,@D50 and @D100 are transact sql decimal variables
DECLARE @DotGain decimal
DECLARE @D0 decimal
DECLARE @D50 decimal
DECLARE @D100 decimal
SET @D0 = 0.10
SET @D50 = 0.54
SET @D100 = 1.20
SELECT @DotGain = 1 - POWER(10,(@D0 - @D50)) / 1 - POWER(10,(@D0 - @D100)) * 100 - 50
but it is giving me different result in TSQL than VB2005
Can someone correct me?
Thanks in advance.
Average Computation Question
Jul 20, 2005My table is laid out as such:ID (int) What (varchar 20) TimeStamp (smalldatetime)------- ------------- ---------------73 Start <T1>73 Misc <T2>73 End <T3>81 Start <T1'>81 Misc <T2'>81 End <T3'>....I need to calculate End - Start for each unique ID (i.e. T3-T1 andT3'-T1') and then take the average of those (2 in this case) entries.Any help is appreciated.Alex.
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