SqlDataAdapter.Update not updating - database

Question

(I should say that im fairly new to vb.net)
I'm having a problem overwriting the entries in my database. I think the problem is that SqlDataAdapter.Update isn't overwriting the database properly with the new datatable info that i've created.
As I understand it, it should totally replace the the info in the database with the datatable when i tell it to update... no?
Here's the problem in a nutshell:
Basically, I have a database (.mdf file) with a table in it called 'test'. I've used SqlDataAdapter to make a dataset using 'test'. I have another datatable that I've made from parsing in a csv - it's called 'ToLoad'. I now want to clear the 'test' datatable, copy in all entries from the csv datatable, then save this to the database.
I've debugged all this and it all seems to work ok, except when I use SqlDataAdapter.Update I get an error telling me I cant duplicate the primary key. This is because the old entries aren't being cleared from the database entirely, before the new ones are being entered from the datatable.
I've checked that the test datatable is being actually cleared early on in the code... and it is.
I've checked that the new csv entries are being copied to the 'test' datatable... and they are.
Any help you can give on this would be really appreciated
Thanks
Craig
'MAKE A NEW SQL CONNECTION
Dim DBConnection As New SqlConnection
'SET THE CONNECTION STRING.
DBConnection.ConnectionString = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Project\Members.mdf;Integrated Security=True"
'OPEN THE CONNECTION TO THE DATABASE
DBConnection.Open()
'OPEN AN ADAPTER AND SELECT EVERYTHING FROM THE 'TEST' TABLE
Dim mySqlDataAdapter As New SqlDataAdapter("SELECT * FROM Test", DBConnection)
Dim mySqlCommandBuilder As New SqlCommandBuilder(mySqlDataAdapter)
Dim DBDataset As DataSet = New DataSet
'FILL THE DATASET WITH THE TEST TABLE
mySqlDataAdapter.Fill(DBDataset, "Test")
'CLEAR ALL ENTRIES IN THE DATATABLE (SO I CAN FILL IT FROM SCRATCH)
DBDataset.Tables("test").Clear()
''SET UP A LOOP TO ADD EACH RECORD FROM THE CSV DATATABLE TO THE DATABASE DATATABLE
Dim CSV_row_number As Int16
CSV_row_number = ds.Tables("toload").Rows.Count
Dim i As Int16
i = 0
Do Until i = CSV_row_number - 1
'MAKES TWO NEW DATAROW OBJECTS
Dim DB_row As DataRow
Dim CSV_row As DataRow
'SET THE CSV_ROW OBJECT EQUAL TO ROW(i) OF THE CSV DATATABLE
CSV_row = ds.Tables("toload").Rows(i)
DB_row = DBDataset.Tables("test").NewRow()
'THIS SETS ALL OF THE COLUMNS IN THIS NEW ROW AS EQUAL TO ROW1 IN THE CSV DATATABLE
DB_row("Name") = CSV_row("Name")
DB_row("Quality") = CSV_row("Address")
DBDataset.Tables("test").Rows.Add(DB_row)
i = i + 1
Loop
mySqlDataAdapter.Update(DBDataset.Tables("Test"))

Answer 1

I managed to fix this myself after a fair bit of googling and some trial and error. Posting my code in case it's useful for anyone else
Craig
'MAKE A NEW SQL CONNECTION
Dim DBConnection As New SqlConnection
'SET THE CONNECTION STRING. YOU GET THIS BY GOING TO SERVER EXPLORER, THEN CLICKING ON THE DATABASE
'THE CONNECTION STRING IS IN PROPERTIES
DBConnection.ConnectionString = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\ME\Project\Members.mdf;Integrated Security=True"
'OPEN THE CONNECTION TO THE DATABASE
DBConnection.Open()
'THIS OPENS AN ADAPTER TO THE DATABASE, AND SELECTS EVERYTHING FROM THE 'TEST' TABLE IN THAT DATABASE
Dim mySqlDataAdapter As New SqlDataAdapter("SELECT * FROM MemberList", DBConnection)
'THIS LETS US USE SQL ON THE DATATABLE (IT GETS PASSED THE ABOVE SQL STATEMENT)
Dim mySqlCommandBuilder As New SqlCommandBuilder(mySqlDataAdapter)
'THIS MAKES ANOTHER NEW DATASET
Dim DBDataset As DataSet = New DataSet
''THIS FILLS THAT DATASET WITH THE TEST TABLE (WHICH THE DATA ADAPTOR GRABBED ABOVE)
mySqlDataAdapter.FillSchema(DBDataset, SchemaType.Source, "MemberList")
mySqlDataAdapter.Fill(DBDataset, "MemberList")
'THIS MAKES A NEW DATATABLE
'I THEN MAKE ALL CHANGES NEEDED
Dim EDITmembers As DataTable
EDITmembers = DBDataset.Tables("MemberList")
''FIRST, IM GOING TO CLEAR ALL ENTRIES IN THE DATATABLE (SO I CAN FILL IT FROM SCRATCH)
'COUNT THE NUMBER OF ENTRIES TO CLEAR
Dim RowsInDB As Integer
RowsInDB = EDITmembers.Rows.Count()
'SET UP A LOOP TO CLEAR THEM
Dim Data_row As DataRow
Dim k As Integer = 0
Do Until k = RowsInDB
Data_row = EDITmembers.Rows(k)
Data_row.Delete()
k = k + 1
Loop
'ONCE ALL THE ROWS ARE CLEARED, SAVE THE CHANGES BY UPDATING THE ACTUAL DATABASE
mySqlDataAdapter.Update(DBDataset, "MemberList")
''THEN I SET UP A LOOP TO ADD EACH RECORD FROM THE CSV DATATABLE TO THE DATABASE DATATABLE
''I FIRST NEED TO KNOW HOW MANY ITERATIONS OF THE LOOP TO DO
Dim CSV_row_number As Int16
'COUNT THE NUMBER OF ROWS AND SET THE ABOVE INT EQUAL TO THIS
CSV_row_number = ToLoad.Rows.Count
Dim j As Int16
j = 0
Do Until j = CSV_row_number - 1
'THIS MAKES TWO NEW DATAROW OBJECTS
Dim DB_row As DataRow
Dim CSV_row As DataRow
'THIS SETS THE CSV_ROW OBJECT EQUAL TO THE FIRST ROW OF THE CSV DATATABLE
CSV_row = ToLoad.Rows(j)
'THIS SETS DB_ROW EQUAL TO A NEW ROW IN THE DATATABLE MADE FROM THE DATABASE
DB_row = EDITmembers.NewRow()
'THIS SETS ALL OF THE COLUMNS IN THIS NEW ROW AS EQUAL TO THE CORRESPONDING ROW IN THE CSV DATATABLE
DB_row("Contact Name") = CSV_row("Contact Name")
DB_row("Do not mail") = CSV_row("Do not mail")
DB_row("Membership Type") = CSV_row("Membership Type")
DB_row("Street Address") = CSV_row("Street Address")
DB_row("Supplemental Address 1") = CSV_row("Supplemental Address 1")
DB_row("Supplemental Address 2") = CSV_row("Supplemental Address 2")
DB_row("City") = CSV_row("City")
DB_row("Postal Code") = CSV_row("Postal Code")
DB_row("Email") = CSV_row("Email")
DB_row("Phone (primary)") = CSV_row("Phone (primary)")
EDITmembers.Rows.Add(DB_row)
j = j + 1
Loop
'UPDATE THE DATABASE WITH ALL THE CHANGES
mySqlDataAdapter.Update(DBDataset, "MemberList")
MessageBox.Show("done!")