SQL violation of Primary Key constraint on update - sql

Question

--EDITED--
I think I figured out the problem. The original row is being taken to update instead of the latest row therefore the CreationDate is the same and since ID + CreationDate is the primary key it returns a violation. Is there any way to select the latest row instead of the original row when updating records?
Thanks :D
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I got the error violation of primary key constraint but I don't know why because my primary key values are unique.
I can add the record for 'Darren' and update it once. After that I get the error. My trigger works such that when I update an existing record, both the original and edited record are inserted into the table ProcessList so that I am able to see all the changes made to all records.
Tables:
CREATE TABLE dbo.ProcessList
(
TransactionID integer IDENTITY,
IsEdited bit DEFAULT 'FALSE',
ID integer NOT NULL,
Name varchar(30) NOT NULL,
Amount smallmoney NOT NULL,
CreationDate datetime DEFAULT GETDATE(),
ModificationDate datetime,
PRIMARY KEY (ID, CreationDate)
)
CREATE TABLE dbo.ProcessListHist
(
TransactionID integer IDENTITY,
IsEdited bit DEFAULT 'FALSE',
ID integer NOT NULL,
Name varchar(30) NOT NULL,
Amount smallmoney NOT NULL,
CreationDate datetime DEFAULT GETDATE(),
ModificationDate datetime,
PRIMARY KEY (ID, CreationDate)
)
Trigger:
CREATE TRIGGER CloneAfterUpdate ON ProcessList
AFTER UPDATE
AS
IF (UPDATE (Amount) OR UPDATE (NAME))
BEGIN
INSERT INTO ProcessListHist (ID, Name, Amount, CreationDate, ModificationDate, IsEdited)
SELECT
ID, Name, Amount, CreationDate, GETDATE(), 'True'
FROM deleted
UPDATE PL
SET PL.CreationDate = PLH.ModificationDate
FROM ProcessList PL
INNER JOIN deleted ON PL.ID = deleted.ID
AND PL.CreationDate = deleted.CreationDate
INNER JOIN ProcessListHist PLH ON PL.ID = PLH.ID
AND PLH.CreationDate = deleted.CreationDate
INSERT INTO ProcessList (ID, Name, Amount, CreationDate, ModificationDate, IsEdited)
SELECT
ID, Name, Amount, CreationDate, ModificationDate, IsEdited
FROM ProcessListHist
END
Insert/Update statements:
INSERT INTO ProcessList (ID, Name, Amount) VALUES ('1020', 'Darren', '300')
UPDATE ProcessList SET Amount = 1000 WHERE Name = 'Darren'

Answer 1

You logging a transaction on your history table right ? , therefore you need to remove the ID of history table from being unique. Make it TransactionID INT only, not an identity, your problem is because every time you perform an UPDATE , the record is inserted into history table, so if the record already exist meaning to say, if the ID is already existing in the history table , you are not allowed to insert the same ID, that's why you will receiving that error.