Question

大家好，我有一个问题。当我尝试在我的程序中使用这段代码将数据库添加到供应商时，我遇到数据类型不匹配错误。据我所知，供应商的状态会产生错误。

如何将名为radActive和radInactive的单选按钮的值存储在数据库中？我应该使用Boolean还是String？我使用Microsoft Access作为我的数据库，Status的字段设置为Yes/No。

这是代码。

Public Sub SupplierInsertData()

    Dim conn As OleDb.OleDbConnection
    Dim cmd As OleDb.OleDbCommand

    Dim SupplierType As String
    Dim Status As Boolean

    'Check for supplier type
    If frmDatabaseSupplier.radLocal.Checked = True Then

        SupplierType = "Local"

    ElseIf frmDatabaseSupplier.radForeign.Checked = True Then

        SupplierType = "Foreign"

    End If

    'Check for supplier status
    If frmDatabaseSupplier.radActive.Checked = True Then

        Status = True

    ElseIf frmDatabaseSupplier.radInactive.Checked = True Then

        Status = False

    End If

    'For inserting of data in the database.
    Dim cmdString As String = "INSERT INTO Supplier(SupplierLastName, SupplierFirstName, SupplierMiddleInitial, " & _
                              "SupplierCompany, SupplierType, SupplierStreetAddress, SupplierCity, SupplierContactNumber, SupplierEmail, " & _
                              "Status)" & _
                              "VALUES('" & frmDatabaseSupplier.txtSupplierLastName.Text & "','" & frmDatabaseSupplier.txtSupplierFirstName.Text & "','" & frmDatabaseSupplier.txtSupplierMiddleInitial.Text & "','" _
                              & frmDatabaseSupplier.txtSupplierCompany.Text & "','" & SupplierType & "', '" & frmDatabaseSupplier.txtSupplierStreetAddress.Text & "','" & frmDatabaseSupplier.txtSupplierCity.Text & "','" _
                              & frmDatabaseSupplier.txtSupplierContactNumber.Text & "','" & frmDatabaseSupplier.txtSupplierEmail.Text & "','" & Status & "')"

    conn = New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\ProjectAnalysisSystem.accdb")

    cmd = New OleDb.OleDbCommand(cmdString, conn)

    conn.Open()
    cmd.ExecuteNonQuery()
    conn.Close()

End Sub

谢谢！

Answer 1

尝试更改代码的最后部分。
您应该使用参数将文本框或变量的值传递给数据库引擎并且不要忘记在using语句中封装像OleDbConnection这样的一次性对象。

Dim cmdString As String = "INSERT INTO Supplier(SupplierLastName, SupplierFirstName, SupplierMiddleInitial, " & _ 
                          "SupplierCompany, SupplierType, SupplierStreetAddress, SupplierCity, SupplierContactNumber, SupplierEmail, " & _ 
                          "Status)" & _ 
                          "VALUES(@supplierName, @supplierFirst, @supplierMiddle, @supplierCo, @supplierType, @supplierStreet, @supplierCity, " & _
                          "@supplierContact, @supplierMail, @status)"
Using conn As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\ProjectAnalysisSystem.accdb")
    Dim cmd As OleDbCommand = New OleDb.OleDbCommand(cmdString, conn))
    cmd.Parameters.AddWithValue("@supplierName", frmDatabaseSupplier.txtSupplierLastName.Text)
    cmd.Parameters.AddWithValue("@supplierFirst", frmDatabaseSupplier.txtSupplierFirstName.Text)
    cmd.Parameters.AddWithValue("@supplierMiddle", frmDatabaseSupplier.txtSupplierMiddleInitial.Text)
    cmd.Parameters.AddWithValue("@supplierCo", frmDatabaseSupplier.txtSupplierCompany.Text )
    cmd.Parameters.AddWithValue("@supplierType", SupplierType)
    cmd.Parameters.AddWithValue("@supplierStreet", frmDatabaseSupplier.txtSupplierStreetAddress.Text)
    cmd.Parameters.AddWithValue("@supplierCity", frmDatabaseSupplier.txtSupplierCity.Text)
    cmd.Parameters.AddWithValue("@supplierContact", frmDatabaseSupplier.txtSupplierContactNumber.Text)
    cmd.Parameters.AddWithValue("@supplierMail", frmDatabaseSupplier.txtSupplierEmail.Text)
    cmd.Parameters.AddWithValue("@status", Status) '<- Here the status var is correctly identified as a boolean, not as a string
    conn.Open() 
    cmd.ExecuteNonQuery() 
End Using

Answer 2

您的数据类型不匹配错误，因为INSERT statement尝试为数据类型为是/否的Status字段存储字符串值。

这不是一个真正的VB.Net问题。如果您从VBA尝试相同的操作，您将从Access的数据库引擎获得相同的错误。这是以下VBA程序的输出。

INSERT INTO Supplier (Status)
VALUES('True')
Error -2147217913 (Data type mismatch in criteria expression.)

程序......

Public Sub Ju_chan()
    Dim cmdString As String
    Dim Status As Boolean
    Dim strMsg As String

On Error GoTo ErrorHandler

    Status = True
    cmdString = "INSERT INTO Supplier (Status)" & vbCrLf & _
        "VALUES('" & Status & "')"
    Debug.Print cmdString
    CurrentProject.Connection.Execute cmdString

ExitHere:
    On Error GoTo 0
    Exit Sub

ErrorHandler:
    strMsg = "Error " & Err.Number & " (" & Err.Description _
        & ")"
    Debug.Print strMsg
    GoTo ExitHere
End Sub

请理解，这并不是为了避免使用参数。我只是想澄清你为什么会收到这个错误。

VB 2008中的数据类型不匹配

2 个答案: