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I am getting a concurrency violation on my updatecommand when I try to save a datatable back to the database. I am changing one column in about 90% of my rows in a 4200 plus row datatable. I am using a datatable that has a primarykey. I am also using a sqlitedatadapter.

I Your help would be appreciated

What I have tried:

fill the datatable with this:

<pre>sql = "SELECT * FROM Customers WHERE Status = 'Active'"
    ActiveCustomersAdapter = New SQLiteDataAdapter(sql, conn)

I fill the table, loop through the table changing one date field by adding an increment variable to a date column and then try to save back to the database with:

Dim cbActiveCustomers As New SQLiteCommandBuilder(ActiveCustomersAdapter)
  conn.Open()                 ... forgot to show this
  conn.Close()                ... and this       thanks MadMyche

There are no concurrent users and no other activity on the database. I am obviously not doing something correctly but have not found what I am missing.
I have searched concurrency issues but most explain issues that do not specifically relate. I have stripped the project back to doing nothing but:
1. open the database and fill the datatable
2. modify the field in about 90% of the tables rows
3. save the table back to the database
Updated 4-Oct-19 17:11pm
MadMyche 28-Sep-19 8:32am
Where is connection.Open()</code) and <code>.Close()
Richard Deeming 30-Sep-19 9:16am
Shouldn't be required for a DataAdapter - it will open and close the connection for you automatically.

1 solution

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Solution 1

I found the cause by starting with an empty database and adding each column and testing for a change and save after each new column is added. All changed and saved OK until I added a date column and this caused the concurrency error even though I was not making any changes to the column. I am therefore assuming (dangerous I know!) that between when the sqliteadapter fills the datatable from the database file and when the sqliteadapter updates the database from the datatable it is thinking the date has been changed, so I will look into how and sqlite handle dates.
Thanks for your input.

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