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VB.NET (MySQL) Saving changes to a datatable to the db

Posted on 2010-11-11
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Last Modified: 2012-05-10
Hi Experts,

i'm using MySQL and VB.Net 2008

I created a dataset with the wizard

in my code i'm doing the following (see code)

What i'm confused about is that it is NOT updating this information to the database.

what am i missing or doing wrong?

the Update returns 0
Inventory_DataTable = New PEQ.inventoryDataTable
Inventory_TableAdapter = New PEQTableAdapters.inventoryTableAdapter
Inventory_TableAdapter.ClearBeforeFill = True
Inventory_TableAdapter.Connection = New MySql.Data.MySqlClient.MySqlConnection(PEQ_CON_STR)

Inventory_TableAdapter.FillByID(Inventory_DataTable, 3)

' now delete the item in slotid 13
Inventory_DataTable.RemoveinventoryRow(Inventory_DataTable.Select("slotid=13")(0))
Inventory_DataTable.AcceptChanges()

' now add a new item in slotid 13
Inventory_DataTable.AddinventoryRow(3, 13, 1868, 1, 4278190080, 0, 0, 0, 0, 0, 0)
Inventory_DataTable.AcceptChanges()
Inventory_TableAdapter.Update(Inventory_DataTable)



' My customization of the fill command
Option Strict Off
Option Explicit On

Imports System
Imports MySql.Data.MySqlClient

Namespace PEQTableAdapters
    Partial Public Class inventoryTableAdapter
        Inherits System.ComponentModel.Component
        Public Property SelectCommand() As MySqlCommand()

            Get
                If (Me._commandCollection Is Nothing) Then
                    Me.InitCommandCollection()
                End If
                Return Me._commandCollection
            End Get

            Set(ByVal value As MySqlCommand())
                Me._commandCollection = value
            End Set

        End Property
        Public Function FillByID(ByVal dataTable As PEQ.inventoryDataTable, ByVal ID As Integer) As Integer
            Dim stSelect As String

            stSelect = Me._commandCollection(0).CommandText
            Try
                Me._commandCollection(0).CommandText += " WHERE charid=" + ID.ToString
                Return Me.Fill(dataTable)
            Catch ex As Exception

            Finally
                Me._commandCollection(0).CommandText = stSelect
            End Try

        End Function
    End Class
End Namespace

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Question by:sgaggerj
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Accepted Solution

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AngryBinary earned 2000 total points
ID: 34117330
After you call AcceptChanges on a DataTable, the state of all modified DataRows goes from "Modified" to "Unchanged". Perhaps the reason you aren't seeing your updates is because the data adapter doesn't think any data has changed. Comment out "AcceptChanges", or move those calls to AFTER the update call.

Also, it wouldn't hurt to make sure that the UpdateCommand for the DataAdapter is populated. Sometimes a command builder can generate the Update command for certain data sources automatically, but sometimes it can't (depending on the particular implementation of the DataAdapter - different DB clients will have different features).
0
 
LVL 1

Author Comment

by:sgaggerj
ID: 34120109
The reason that i used the AcceptChanges was when i first tried it it gave me a duplicate key error, as there are two primary keys in the table.  The primary keys are the 1st two fields in the row (in the example above '3' and '13')

commenting them out did in fact give me the same error.

it appears that the update IS populated too.
0
 
LVL 1

Author Comment

by:sgaggerj
ID: 34120170
i just tried updating the actual row data, rather than deleting and adding a new row, and it DOES update the database (Result of the update = 1)

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LVL 1

Author Comment

by:sgaggerj
ID: 34120189
it appears that the deleting is not working, i tried to delete that single row, and it did delete it from my table, but upon update it did not remove the row from the database.
0
 
LVL 1

Author Comment

by:sgaggerj
ID: 34120457
I think i figured it out.

the 'RemoveinventoryRow' only removes it from the datatable, it doesn't delete it.

i needed to use 'Delete' on the row

Inventory_DataTable.Select("slotid=13")(0).Delete

then it worked.
0
 
LVL 1

Author Closing Comment

by:sgaggerj
ID: 34120468
Got me looking in the right direction, Thanks!!
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