Copy Distinct Records Based on 3 Cols - sql-server

Question

I have loads of data in a table called Temp. This data consists of duplicates.
Not Entire rows but the same data in 3 columns. They are HouseNo,DateofYear,TimeOfDay.
I want to copy only the distinct rows from "Temp" into another table, "ThermData."
Basically what i want to do is copy all the distinct rows from Temp to ThermData where distinct(HouseNo,DateofYear,TimeOfDay). Something like that.
I know we can't do that. An alternative to how i can do that.
Do help me out. I have tried lots of things but haven't solved got it.
Sample Data. Values which are repeated are like....
I want to delete the duplicate row based on the values of HouseNo,DateofYear,TimeOfDay
HouseNo DateofYear TimeOfDay Count
102 10/1/2009 0:00:02 AM 2
102 10/1/2009 1:00:02 AM 2
102 10/1/2009 10:00:02 AM 2

Answer 1

Here is a Northwind example based on the Orders table.
There are duplicates based on the (EmployeeID , ShipCity , ShipCountry) columns.
If you only execute the code between these 2 lines:
/* Run everything below this line to show crux of the fix */
/* Run everything above this line to show crux of the fix */
you'll see how it works. Basically:
(1) You run a GROUP BY on the 3 columns of interest. (derived1Duplicates)
(2) Then you join back to the table using these 3 columns. (on ords.EmployeeID = derived1Duplicates.EmployeeID and ords.ShipCity = derived1Duplicates.ShipCity and ords.ShipCountry = derived1Duplicates.ShipCountry)
(3) Then for each group, you tag them with Cardinal numbers (1,2,3,4,etc) (using ROW_NUMBER())
(4) Then you keep the row in each group that has the cardinal number of "1". (where derived2DuplicatedEliminated.RowIDByGroupBy = 1)
Use Northwind
GO
declare #DestinationVariableTable table (
NotNeededButForFunRowIDByGroupBy int not null ,
NotNeededButForFunDuplicateCount int not null ,
[OrderID] [int] NOT NULL,
[CustomerID] [nchar](5) NULL,
[EmployeeID] [int] NULL,
[OrderDate] [datetime] NULL,
[RequiredDate] [datetime] NULL,
[ShippedDate] [datetime] NULL,
[ShipVia] [int] NULL,
[Freight] [money] NULL,
[ShipName] [nvarchar](40) NULL,
[ShipAddress] [nvarchar](60) NULL,
[ShipCity] [nvarchar](15) NULL,
[ShipRegion] [nvarchar](15) NULL,
[ShipPostalCode] [nvarchar](10) NULL,
[ShipCountry] [nvarchar](15) NULL
)
INSERT INTO #DestinationVariableTable (NotNeededButForFunRowIDByGroupBy , NotNeededButForFunDuplicateCount , OrderID,CustomerID,EmployeeID,OrderDate,RequiredDate,ShippedDate,ShipVia,Freight,ShipName,ShipAddress,ShipCity,ShipRegion,ShipPostalCode,ShipCountry )
Select RowIDByGroupBy , MyDuplicateCount , OrderID,CustomerID,EmployeeID,OrderDate,RequiredDate,ShippedDate,ShipVia,Freight,ShipName,ShipAddress,ShipCity,ShipRegion,ShipPostalCode,ShipCountry
From
(
/* Run everything below this line to show crux of the fix */
Select
RowIDByGroupBy = ROW_NUMBER() OVER(PARTITION BY ords.EmployeeID , ords.ShipCity , ords.ShipCountry ORDER BY ords.OrderID )
, derived1Duplicates.MyDuplicateCount
, ords.*
from
[dbo].[Orders] ords
join
(
select EmployeeID , ShipCity , ShipCountry , COUNT(*) as MyDuplicateCount from [dbo].[Orders] GROUP BY EmployeeID , ShipCity , ShipCountry /*HAVING COUNT(*) > 1*/
) as derived1Duplicates
on ords.EmployeeID = derived1Duplicates.EmployeeID and ords.ShipCity = derived1Duplicates.ShipCity and ords.ShipCountry = derived1Duplicates.ShipCountry
/* Run everything above this line to show crux of the fix */
)
as derived2DuplicatedEliminated
where derived2DuplicatedEliminated.RowIDByGroupBy = 1
select * from #DestinationVariableTable
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