Question

我正在使用Winforms应用程序，该应用程序具有多选项卡表单，并且已链接到Visual Studio Community 2017中的MySQL数据库。该表单具有bindingsource和bindingnavigator控件。我的基本数据库结构如下：-

耗材

SupplyID（pk） SupplyName

年份

YearID（pk） YearNumber

颜色

ColourID（pk）颜色名称

订单

OrderID（pk）订单名称 SupplyID_fk（fk） CatalogID_fk（fk） YearID_fk（fk） ColourID_fk（fk）

“订单”表中有四个组合框：CboSupplyID_fk，CboCatalogID_fk，CboYearID_fk和CboColourID_fk。我的问题是，当我尝试使用bindingnavigator记录选择器导航到下一条记录时（CboColourID_fk除外，它可以正常工作）。 vb.net代码如下所示：-

Imports MySql
Imports MySql.Data.MySqlClient
Imports MySql.Data

Public Class Form1
    Inherits Form

Dim cbCatalog As New MySqlCommandBuilder(daCatalog)
Dim cbYears As New MySqlCommandBuilder(daYears)
Dim cbOrderTypes As New MySqlCommandBuilder(daOrderTypes)
Dim cbOrderColours As New MySqlCommandBuilder(daOrderColours)
Dim dsCatalog As New DataSet
Dim dsYears As New DataSet
Dim dsOrderTypes As New DataSet
Dim dsOrderColours As New DataSet
Dim dsOrders As New DataSet
Dim dsSupplies As New DataSet
Dim dtCatalog As New DataTable
Dim dtYears As New DataTable
Dim dtOrderTypes As New DataTable
Dim dtOrderColours As New DataTable
Dim dtOrders As New DataTable
Dim dtOrderColours As New DataTable
Dim dtSupplies As New DataTable
Dim daCatalog As New MySqlDataAdapter
Dim daYears As New MySqlDataAdapter
Dim daOrderTypes As New MySqlDataAdapter
Dim daOrderColours As New MySqlDataAdapter
Dim daOrders As New MySqlDataAdapter
Dim daSupplies As New MySqlDataAdapter

Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles MyBase.Shown
    MysqlConn.ConnectionString =
    "server=localhost;Port=3306;database=mydatabase;userid=root;password=mypassword;persist security info=True"
    daOrders = New MySqlDataAdapter("SELECT * FROM Orders", MysqlConn)
    daOrders.MissingSchemaAction = MissingSchemaAction.AddWithKey
    Dim dsOrders As New DataSet
    dtOrders = New DataTable("Orders")
    daOrders.Fill(dtOrders)
    dsOrders.Tables.Add(dtOrders)
    Dim cbOrders As New MySqlCommandBuilder(daOrders)
    daSupplies = New MySqlDataAdapter("SELECT * FROM Supplies", MysqlConn)
    dtSupplies = New DataTable("Supplies")
    daSupplies.Fill(dtSupplies)
    dsOrders.Tables.Add(dtSupplies)
    cbOrders = New MySqlCommandBuilder(daSupplies)

    daCatalog = New MySqlDataAdapter("SELECT * FROM Catalog", MysqlConn)
    dtCatalog = New DataTable("Catalog")
    daCatalog.Fill(dtCatalog)
    dsOrders.Tables.Add(dtCatalog)
    cbOrders = New MySqlCommandBuilder(daCatalog)

    daYears = New MySqlDataAdapter("SELECT * FROM Years", MysqlConn)
    dtYears = New DataTable("Years")
    daYears.Fill(dtYears)
    dsOrders.Tables.Add(dtYears)
    cbOrders = New MySqlCommandBuilder(daYears)


    daOrderTypes = New MySqlDataAdapter("SELECT * FROM OrderTypes", MysqlConn)
    dtOrderTypes = New DataTable("OrderTypes")
    daOrderTypes.Fill(dtOrderTypes)
    dsOrders.Tables.Add(dtOrderTypes)
    cbOrders = New MySqlCommandBuilder(daOrderTypes)

    daOrderColours = New MySqlDataAdapter("SELECT * FROM OrderColours", MysqlConn)
    dtOrderColours = New DataTable("OrderColours")
    daOrderColours.Fill(dtOrderColours)
    dsOrders.Tables.Add(dtOrderColours)
    cbOrders = New MySqlCommandBuilder(daOrderColours)

    dtOrders.Columns("OrderID").AutoIncrement = True
    dtSupplies.Columns("SupplyID").AutoIncrement = True

    dtOrders.Columns(0).AutoIncrementSeed = dtSupplies.Rows.Cast(Of DataRow).Max(Function(dr As DataRow) CInt(dr.Item(0))) + 1
    dtSupplies.Columns(0).AutoIncrementStep = 1

    dtSupplies.Columns(0).AutoIncrementSeed = dtSupplies.Rows.Cast(Of DataRow).Max(Function(dr) CInt(dr.Item(0))) + 1
    dtSupplies.Columns(0).AutoIncrementStep = 1

    dsOrders.Relations.Add(New DataRelation("relationSupply", dsOrders.Tables("Supplies").Columns("SupplyID"), dsOrders.Tables("Orders").Columns("SupplyID_fkey")))

    SupplyBindingSource = New BindingSource(dsOrders, "Supplies")

    CboSupplyID_fkey.DisplayMember = "SupplyNumber"
    CboSupplyID_fkey.ValueMember = "SupplyID"
    CboSupplyID_fkey.DataSource = SupplyBindingSource

    OrderBindingSource = New BindingSource(SupplyBindingSource, "relationSupply")

    'bind the Supply's foreign key to the combobox's "SelectedValue" '
    Me.CboSupplyID_fkey.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.OrderBindingSource, "SupplyID_fkey", True))


    dtOrders.Columns("OrderID").AutoIncrement = True
    dtCatalog.Columns("CatalogCodeID").AutoIncrement = True

    dtOrders.Columns(0).AutoIncrementSeed = dtCatalog.Rows.Cast(Of DataRow).Max(Function(dr As DataRow) CInt(dr.Item(0))) + 1
    dtCatalog.Columns(0).AutoIncrementStep = 1

    dtCatalog.Columns(0).AutoIncrementSeed = dtCatalog.Rows.Cast(Of DataRow).Max(Function(dr) CInt(dr.Item(0))) + 1
    dtCatalog.Columns(0).AutoIncrementStep = 1

    dsOrders.Relations.Add(New DataRelation("relationCatalog", dsOrders.Tables("Catalog").Columns("CatalogCodeID"), dsOrders.Tables("Orders").Columns("CatalogCodeID_fk")))

    CatalogBindingSource = New BindingSource(dsOrders, "Catalog")

    CboCatalogCodeID_fk.DisplayMember = "CatalogDescription"
    CboCatalogCodeID_fk.ValueMember = "CatalogCodeID"
    CboCatalogCodeID_fk.DataSource = CatalogBindingSource

    OrderBindingSource = New BindingSource(CatalogBindingSource, "relationCatalog")

    'to clear previous binding and then add new binding '
    CboSupplyID_fkey.DataBindings.Clear()

    'bind the Catalog Guide's foreign key to the combobox's "SelectedValue" '
    Me.CboCatalogCodeID_fk.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.OrderBindingSource, "CatalogCodeID_fk", True))

    dtOrders.Columns("OrderID").AutoIncrement = True
    dtYears.Columns("YearID").AutoIncrement = True

    dtOrders.Columns(0).AutoIncrementSeed = dtYears.Rows.Cast(Of DataRow).Max(Function(dr As DataRow) CInt(dr.Item(0))) + 1
    dtYears.Columns(0).AutoIncrementStep = 1

    dtYears.Columns(0).AutoIncrementSeed = dtYears.Rows.Cast(Of DataRow).Max(Function(dr) CInt(dr.Item(0))) + 1
    dtYears.Columns(0).AutoIncrementStep = 1

    dsOrders.Relations.Add(New DataRelation("relationYears", dsOrders.Tables("Years").Columns("YearID"), dsOrders.Tables("Orders").Columns("YearID_fk")))

    YearBindingSource = New BindingSource(dsOrders, "Years")

    CboYearID_fk.DisplayMember = "YearNumber"
    CboYearID_fk.ValueMember = "YearID"
    CboYearID_fk.DataSource = YearBindingSource

    OrderBindingSource = New BindingSource(YearBindingSource, "relationYears")

    'to clear previous binding and then add new binding '
    CboCatalogCodeID_fk.DataBindings.Clear()

    'bind the Year's foreign key to the combobox's "SelectedValue" '
    Me.CboYearID_fk.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.OrderBindingSource, "YearID_fk", True))



    dtOrders.Columns("OrderID").AutoIncrement = True
    dtOrderTypes.Columns("OrderTypeID").AutoIncrement = True

    dtOrders.Columns(0).AutoIncrementSeed = dtOrderTypes.Rows.Cast(Of DataRow).Max(Function(dr As DataRow) CInt(dr.Item(0))) + 1
    dtOrderTypes.Columns(0).AutoIncrementStep = 1

    dtOrderTypes.Columns(0).AutoIncrementSeed = dtOrderTypes.Rows.Cast(Of DataRow).Max(Function(dr) CInt(dr.Item(0))) + 1
    dtOrderTypes.Columns(0).AutoIncrementStep = 1

    dsOrders.Relations.Add(New DataRelation("relationOrderTypes", dsOrders.Tables("OrderTypes").Columns("OrderTypeID"), dsOrders.Tables("Orders").Columns("OrderTypeID_fk")))

    OrderTypeBindingSource = New BindingSource(dsOrders, "OrderTypes")

    CboOrderTypeID_fk.DisplayMember = "OrderType"
    CboOrderTypeID_fk.ValueMember = "OrderTypeID"
    CboOrderTypeID_fk.DataSource = OrderTypeBindingSource

    OrderBindingSource = New BindingSource(OrderTypeBindingSource, "relationOrderTypes")

    'to clear previous binding and then add new binding '
    CboYearID_fk.DataBindings.Clear()

    'bind the Order Type's foreign key to the combobox's "SelectedValue" '
    Me.CboOrderTypeID_fk.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.OrderBindingSource, "OrderTypeID_fk", True))


    dtOrders.Columns("OrderID").AutoIncrement = True
    dtOrderColours.Columns("ColourID").AutoIncrement = True

    dtOrders.Columns(0).AutoIncrementSeed = dtOrderColours.Rows.Cast(Of DataRow).Max(Function(dr As DataRow) CInt(dr.Item(0))) + 1
    dtOrderColours.Columns(0).AutoIncrementStep = 1

    dtOrderColours.Columns(0).AutoIncrementSeed = dtOrderColours.Rows.Cast(Of DataRow).Max(Function(dr) CInt(dr.Item(0))) + 1
    dtOrderColours.Columns(0).AutoIncrementStep = 1

    dsOrders.Relations.Add(New DataRelation("relationColours", dsOrders.Tables("OrderColours").Columns("ColourID"), dsOrders.Tables("Orders").Columns("ColourID_fk")))

    OrderColourBindingSource = New BindingSource(dsOrders, "OrderColours")

    cboColourID_fk.DisplayMember = "Colour"
    cboColourID_fk.ValueMember = "ColourID"
    cboColourID_fk.DataSource = OrderColourBindingSource

    OrderBindingSource = New BindingSource(OrderColourBindingSource, "relationColours")

    'to clear previous binding and then add new binding '
    CboOrderTypeID_fk.DataBindings.Clear()

    'bind the Catalog Guide's foreign key to the combobox's "SelectedValue" '
    Me.cboColourID_fk.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.OrderBindingSource, "ColourID_fk", True))


    'Bind the DataTable to the UI via a BindingSource. '
    OrderBindingSource.DataSource = dtOrders
    Me.OrderBindingNavigator.BindingSource = Me.OrderBindingSource

    txtOrderID.DataBindings.Add("Text", Me.OrderBindingSource, "OrderID")
    txtOrderName.DataBindings.Add("Text", Me.OrderBindingSource, "OrderName")
End Sub
End Class

Answer 1

感谢您的帮助。我可以使用以下vb.net代码解决我的问题：-

        MysqlConn = New MySqlConnection()

    ' Define the SQL to grab data from table.
    CmdSQLSelectOrders = "SELECT * FROM Orders"

    'Connection String
    MysqlConn.ConnectionString =
      "server=localhost;Port=3306;database=mydatabase;userid=root;password=mypassword;persist security info=True"
    daOrders.MissingSchemaAction = MissingSchemaAction.AddWithKey
    ' Try, Catch, Finally
    Try
        MysqlConn.Open()

        MysqlCmd.Connection = MysqlConn
        MysqlCmd.CommandText = CmdSQLSelectOrders

        daOrders.SelectCommand = MysqlCmd
        daOrders.Fill(dtOrders)

        daSupplies = New MySqlDataAdapter("SELECT * FROM Supplies", MysqlConn)
        dtSupplies = New DataTable("Supplies")
        daSupplies.Fill(dtSupplies)
        dsOrders.Tables.Add(dtSupplies)

        daCatalog = New MySqlDataAdapter("SELECT * FROM Catalog", MysqlConn)
        dtCatalog = New DataTable("Catalog")
        daCatalog.Fill(dtCatalog)
        dsOrders.Tables.Add(dtCatalog)

        daYears = New MySqlDataAdapter("SELECT * FROM Years", MysqlConn)
        dtYears = New DataTable("Years")
        daYears.Fill(dtYears)
        dsOrders.Tables.Add(dtYears)

        daOrderTypes = New MySqlDataAdapter("SELECT * FROM OrderTypes", MysqlConn)
        dtOrderTypes = New DataTable("OrderTypes")
        daOrderTypes.Fill(dtOrderTypes)
        dsOrders.Tables.Add(dtOrderTypes)

        daOrderColours = New MySqlDataAdapter("SELECT * FROM OrderColours", MysqlConn)
        dtOrderColours = New DataTable("OrderColours")
        daOrderColours.Fill(dtOrderColours)
        dsOrders.Tables.Add(dtOrderColours)

        Me.CboSupplyID_fkey.DisplayMember = "SupplyNumber"
        Me.CboSupplyID_fkey.ValueMember = "SupplyID"
        Me.CboSupplyID_fkey.DataSource = SupplyBindingSource

        Me.CboCatalogID_fk.DisplayMember = "CatalogDescription"
        Me.CboCatalogID_fk.ValueMember = "CatalogID"
        Me.CboCatalogID_fk.DataSource = CatalogBindingSource

        Me.CboYearID_fk.DisplayMember = "Year"
        Me.CboYearID_fk.ValueMember = "YearID"
        Me.CboYearID_fk.DataSource = YearBindingSource


        Me.CboOrderTypeID_fk.DisplayMember = "OrderType"
        Me.CboOrderTypeID_fk.ValueMember = "OrderTypeID"
        Me.CboOrderTypeID_fk.DataSource = OrderTypeBindingSource

        Me.CboColourID_fk.DisplayMember = "Colour"
        Me.CboColourID_fk.ValueMember = "ColourID"
        Me.CboColourID_fk.DataSource = OrderColourBindingSource

        Me.OrderBindingSource.DataSource = ds.Tables("dtSupplies")
        Me.OrderBindingSource.DataSource = ds.Tables("dtCatalog")
        Me.OrderBindingSource.DataSource = ds.Tables("dtYears")
        Me.OrderBindingSource.DataSource = ds.Tables("dtOrderTypes")
        Me.OrderBindingSource.DataSource = ds.Tables("dtOrderColours")

        Me.OrderBindingNavigator.BindingSource = Me.OrderBindingSource

        Me.CboSupplyID_fk.DataBindings.Add("SelectedValue", Me.OrderBindingSource, "SupplyID_fk", True)
        Me.CboCatalogID_fk.DataBindings.Add("SelectedValue", Me.OrderBindingSource, "CatalogID_fk", True)
        Me.CboYearID_fk.DataBindings.Add("SelectedValue", Me.OrderBindingSource, "YearID_fk", True)
        Me.CboOrderTypeID_fk.DataBindings.Add("SelectedValue", Me.OrderBindingSource, "OrderTypeID_fk", True)
        Me.CboColourID_fk.DataBindings.Add("SelectedValue", Me.OrderBindingSource, "ColourID_fk", True)

    Catch myerror As MySqlException
        MessageBox.Show("Cannot connect to database: " & myerror.Message)
    Finally
        MysqlConn.Close()
        MysqlConn.Dispose()
    End Try

组合框未使用bindingnavigator记录选择器显示下一条记录

耗材

目录

年份

颜色

订单

1 个答案: