How to solve the "Cannot Update Identity Column" error

Hi,

If you have the column set to identity specification you should also set AutoIncrement to true (if you don't have any perticular logic to handle the automatic incrementation already) and seed to whatever suits your application (usually 1). Also, if you in existing logic have insert / update queries putting / updating values of that particular column you need to rewrite them to exclude the identity specification column.

/Carl.

yes i did that in sql server
I modify the table and i did set seed and increament to 1

Hi,

Yes, but have you updated the sql queries for update / insert to reflect this change?

/Carl.

you mean to configure the dataset again?

Hi,

Otherwise, try using SET IDENTITY_INSERT <tablename> ON , i.e. (SQL Code example for copying between two tables):

ALTER TABLE <tablename> DISABLE TRIGGER MyTrigger

SET IDENTITY_INSERT <tablename> ON

INSERT INTO <tablename> (IDCol, Col1, Col2, Col3, Col4)
  SELECT IDCol, Col1, Col2, Col3, Col4 FROM <tablename2>
  WHERE IDCol=<value>

SET IDENTITY_INSERT <tablename> OFF

ALTER TABLE <tablename> ENABLE TRIGGER MyTrigger

/Carl.

before that ....let me ask you something
my [A/A] filed is not my primary KEy
primary key is Key_Personnel which is identity specificationi
i saw that i am not allowed to set 2 fileds with identity.

Hi,

Ok, there is really no point in having two fields as identity. The reason for an identity field is to ensure unique identification of each commited row. My recommendation would be to have one field acting as both primary key / identity specification with autoincrement.

/Carl.

so can i use for the [A/A] field this?
Dim lastrow As Int32
       lastrow = PersonnelDataSet.Tables(0).Rows.Count - 1
       A_ATextBox.Text = CStr(CDbl(CDbl(PersonnelDataSet.Tables(0).Rows(lastrow).Item(1).ToString) + 1))
in my form load event? this one just add +1 increament in the last A/A
is this logical? would this work?

my dought is about duplicates values

Sorry for my delay.....i was Flying To brussels and back to greece.
It works ....
here is what i've done according to your suggestion...
i increase the point value...but check my code for other suggestion..thank you very much....

 Me.PersonnelBindingSource.AddNew()
       
        Dim conn As New SqlConnection(My.Settings.MyconnectionString)
        If conn.State = ConnectionState.Open Then conn.Close()
        conn.Open()
 
        Dim strMax As String = "SELECT MAX([A/A]) AS MaxCount FROM Personnel"
        Dim maxCount As New SqlCommand(strMax, conn)
        Dim maxAA As Integer = CInt(maxCount.ExecuteScalar())
        Dim newAA As Integer = maxAA + 1
        
A_ATextBox.Text = CStr(newAA)
        ..
..
..
 
        conn.close()

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Plz check my last comment and correct me if for any mistakes ...
note that ...all my code is in my form load event...

Hi,

It seems to check out.

/Carl.