How to select and duplicate the records and update some column values using cursor

Question

I have a table with 920 records, we need to update the end date to 6/30/2014 for 920 records and I need to create all 920 records with start date is 7/1/2014 and update the external value to
CCC.
Note: the table primary key is not auto increment, but I have sp to get the latest key for that.
Existing table.  
ID
Source Name
Internal value
External value
Start date
End date
1
XXX
AAA
BBB
1/1/2013
6/30/2015
Create new records
ID
Source Name
Internal value
External value
Start date
End date
921
XXX
AAA
CCC
7/1/2013
12/30/2015

Answer 1

Hi ManuGT
If I understand what you need then you ask for:
1. updating all current rows (920 rows in the table now)
2. insert new rows which are duplicates of the preiviews rows, but with value 'CCC' insteade of 'BBB'
If so, there is not reason to use a cursor and it is highly NOT RECOMMENDED to use ant type of loop.
You should work with SET and do it all in 2 simple queries:
-- first we duplicate the existing rows,
-- but we use the values 'CCC" and '20140107' for the new rows values
INSERT test (SourceName, InternalValue, ExternalValue, StartDate, EndDate)
select SourceName, 'CCC', ExternalValue, '20140107' , EndDate
from test
where
-- You can use any filter that you need if you dont want to update all rows
InternalValue = 'AAA' and ExternalValue = 'BBB' and StartDate = '20140101' and EndDate = '20140630'
-- Now we update the old rows (check the filter! I get only the old rows since I filter the new rown out)
UPDATE test
SET EndDate = '20140107' -- I use date in format yyyymmdd, You can use other formats as well
where
-- You can use any filter that you need if you dont want to update all rows
InternalValue = 'AAA' and ExternalValue = 'BBB' and StartDate = '20140101' and EndDate = '20140630'
Unfortunately you did not post DDL+DML! Therefore we cant see your table structure and the data sample and we can only guess. I used Saeid's post as the basic DDL+DML.
Please next time post DDL+DML
here is the full code with the DDL+DML that i used:
-- This is our DDL - A create table query:
create table test
( id int identity(1,1) primary key,
SourceName nvarchar(3),
InternalValue nvarchar(3),
ExternalValue nvarchar(3),
StartDate date,
EndDate date
go
-- This is our DML - A query that insert some sample data
declare @i int = 1 ;
while @i < 921
begin
insert test (SourceName, InternalValue, ExternalValue, StartDate, EndDate)
values ('XXX', 'AAA', 'BBB', '1/1/2014', '6/30/2014' ) ;
set @i += 1 ;
end ;
GO
-- Here is the solution for the problem as I understood your needs:
-- first we duplicate the existing rows,
-- but we use the values 'CCC" and '20140107' for the new rows values
INSERT test (SourceName, InternalValue, ExternalValue, StartDate, EndDate)
select SourceName, 'CCC', ExternalValue, '20140107' , EndDate
from test
where
-- You can use any filter that you need if you dont want to update all rows
InternalValue = 'AAA' and ExternalValue = 'BBB' and StartDate = '20140101' and EndDate = '20140630'
-- Now we update the old rows (check the filter! I get only the old rows since I filter the new rown out)
UPDATE test
SET EndDate = '20140107' -- I use date in format yyyymmdd, You can use other formats as well
where
-- You can use any filter that you need if you dont want to update all rows
InternalValue = 'AAA' and ExternalValue = 'BBB' and StartDate = '20140101' and EndDate = '20140630'
-- Here we just check how the result look like :-)
select *
from test ;
-- And since we do not realy need this table in our server... Here we clean the DDL (you probaby DO NOT WANT TO EXECUTE THIS!)
DROP table test
GO
I hope this was useful :-)
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