我的更新方法不使用 localdb 在 vb.net 中更新我的数据库中的任何数据

Question

对不起新手，我正在制作一个可以插入、删除和更新的库存。但问题是我想要更新的所有数据都没有真正更新。我总是去“记录未更新”然后我再次尝试更新下一个问题是“变量名'@date'已经被声明。变量名在查询批处理或存储过程中必须是唯一的。”

Public Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

    Dim iii As Integer

    Try
        cn.Open()
        cmd.CommandText = "UPDATE service SET date=@date ,tech_assign=@tech_assign,err_one=@err_one,err_two= @err_two,err_tri = @err_tri,err_other = @err_other,err_other_spec = @err_other_spec,act_one = @act_one,act_two = @act_two,act_other = @act_other,act_other_spec = @act_other_spec,request = @request,op_unit = @op_unit WHERE serv_Id= @serv_Id"
        cmd.Connection = cn
        cmd.Parameters.AddWithValue("@date", DateDateTimePicker.Text)
        cmd.Parameters.AddWithValue("@tech_assign", Tech_assignTextBox.Text)
        cmd.Parameters.AddWithValue("@err_one", Err_oneCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@err_two", Err_twoCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@err_tri", Err_triCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@err_other", Err_otherCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@err_other_spec", Err_other_specTextBox.Text)
        cmd.Parameters.AddWithValue("@act_one", Act_oneCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@act_two", Act_twoCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@act_other", Act_otherCheckBox.CheckState)
        cmd.Parameters.AddWithValue("@act_other_spec", Act_other_specTextBox.Text)
        cmd.Parameters.AddWithValue("@request", RequestTextBox.Text)
        cmd.Parameters.AddWithValue("@op_unit", Op_unitTextBox.Text)
        cmd.Parameters.AddWithValue("@serv_Id", i)
        iii = cmd.ExecuteNonQuery()

        If iii <> 0 Then
            MsgBox("Record Updated Succesfully!", MessageBoxIcon.Information)
        Else
            MsgBox("Record Not Updated", MessageBoxIcon.Warning)
        End If

        cn.Close()
        Me.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    Finally
        If cn.State = ConnectionState.Open Then
            cn.Close()
        End If
    End Try
End Sub

@Steve 这是我在表单中的全部代码，我在另一个表单的 datagridview 中使用 i

导入 System.Data 导入 System.Data.SqlClient

公开课表3

Dim cn As New SqlConnection("Data Source=(LocalDB)\v11.0;AttachDbFilename=c:\Users\Carlo\Documents\Visual Studio 2013\Projects\WindowsApplication5\WindowsApplication5\db.mdf;Integrated Security=True")
Dim cmd As New SqlCommand
Dim da As New SqlDataAdapter
Dim dt As New DataTable
Dim ds As New DataSet

Dim aa As String
Dim i As Integer

Public Sub getText(ByVal a As String)
    aa = a
End Sub

Public Sub getId(ByVal into As Integer)
    into = i
End Sub

Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    If aa = "Save" Then
        Button1.Enabled = True
        Button1.Visible = True
        Button2.Enabled = False
        Button2.Visible = False

        Me.DateDateTimePicker.Text = Now
        Me.Tech_assignTextBox.Text = " "
        Me.Err_oneCheckBox.CheckState = CheckState.Unchecked
        Me.Err_twoCheckBox.CheckState = CheckState.Unchecked
        Me.Err_triCheckBox.CheckState = CheckState.Unchecked
        Me.Err_otherCheckBox.CheckState = CheckState.Unchecked
        Me.Err_other_specTextBox.Text = " "
        Me.Act_oneCheckBox.CheckState = CheckState.Unchecked
        Me.Act_twoCheckBox.CheckState = CheckState.Unchecked
        Me.Act_otherCheckBox.CheckState = CheckState.Unchecked
        Me.Act_other_specTextBox.Text = " "
        Me.RequestTextBox.Text = " "
        Me.Op_unitTextBox.Text = " "

    ElseIf aa = "Update" Then
        Button1.Enabled = False
        Button1.Visible = False
        Button2.Enabled = True
        Button2.Visible = True

        Me.DateDateTimePicker.Text = Form2.ServiceDataGridView.Item(1, i).Value
        Me.Tech_assignTextBox.Text = Form2.ServiceDataGridView.Item(2, i).Value

        If Me.Err_oneCheckBox.CheckState = Form2.ServiceDataGridView.Item(3, i).Value = "False" Then
            Me.Err_oneCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Err_oneCheckBox.CheckState = Form2.ServiceDataGridView.Item(3, i).Value = "True" Then
            Me.Err_oneCheckBox.CheckState = CheckState.Unchecked
        End If

        If Me.Err_twoCheckBox.CheckState = Form2.ServiceDataGridView.Item(4, i).Value = "False" Then
            Me.Err_twoCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Err_twoCheckBox.CheckState = Form2.ServiceDataGridView.Item(4, i).Value = "True" Then
            Me.Err_twoCheckBox.CheckState = CheckState.Unchecked
        End If

        If Me.Err_triCheckBox.CheckState = Form2.ServiceDataGridView.Item(5, i).Value = "False" Then
            Me.Err_triCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Err_triCheckBox.CheckState = Form2.ServiceDataGridView.Item(5, i).Value = "True" Then
            Me.Err_triCheckBox.CheckState = CheckState.Unchecked
        End If

        If Me.Err_otherCheckBox.CheckState = Form2.ServiceDataGridView.Item(6, i).Value = "False" Then
            Me.Err_otherCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Err_otherCheckBox.CheckState = Form2.ServiceDataGridView.Item(6, i).Value = "True" Then
            Me.Err_otherCheckBox.CheckState = CheckState.Unchecked
        End If

        Me.Err_other_specTextBox.Text = Form2.ServiceDataGridView.Item(7, i).Value

        If Me.Act_oneCheckBox.CheckState = Form2.ServiceDataGridView.Item(8, i).Value = "False" Then
            Me.Act_oneCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Act_oneCheckBox.CheckState = Form2.ServiceDataGridView.Item(8, i).Value = "True" Then
            Me.Act_oneCheckBox.CheckState = CheckState.Unchecked
        End If

        If Me.Act_twoCheckBox.CheckState = Form2.ServiceDataGridView.Item(9, i).Value = "False" Then
            Me.Act_twoCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Act_twoCheckBox.CheckState = Form2.ServiceDataGridView.Item(9, i).Value = "True" Then
            Me.Act_twoCheckBox.CheckState = CheckState.Unchecked
        End If

        If Me.Act_otherCheckBox.CheckState = Form2.ServiceDataGridView.Item(10, i).Value = "False" Then
            Me.Act_otherCheckBox.CheckState = CheckState.Checked
        ElseIf Me.Act_otherCheckBox.CheckState = Form2.ServiceDataGridView.Item(10, i).Value = "True" Then
            Me.Act_otherCheckBox.CheckState = CheckState.Unchecked
        End If

        Me.Act_other_specTextBox.Text = Form2.ServiceDataGridView.Item(11, i).Value

        Me.RequestTextBox.Text = Form2.ServiceDataGridView.Item(12, i).Value
        Me.Op_unitTextBox.Text = Form2.ServiceDataGridView.Item(13, i).Value

    End If

End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Try

        cn.Open()
        Using cmd As New SqlClient.SqlCommand("INSERT INTO service (date,tech_assign,err_one,err_two,err_tri,err_other,err_other_spec,act_one,act_two,act_other,act_other_spec,request,op_unit) VALUES(@date,@tech_assign,@err_one,@err_two,@err_tri,@err_other,@err_other_spec,@act_one,@act_two,@act_other,@act_other_spec,@request,@op_unit)", cn)
            cmd.Parameters.AddWithValue("@date", DateDateTimePicker.Text)
            cmd.Parameters.AddWithValue("@tech_assign", Tech_assignTextBox.Text)
            cmd.Parameters.AddWithValue("@err_one", Err_oneCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@err_two", Err_twoCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@err_tri", Err_triCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@err_other", Err_otherCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@err_other_spec", Err_other_specTextBox.Text)
            cmd.Parameters.AddWithValue("@act_one", Act_oneCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@act_two", Act_twoCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@act_other", Act_otherCheckBox.CheckState)
            cmd.Parameters.AddWithValue("@act_other_spec", Act_other_specTextBox.Text)
            cmd.Parameters.AddWithValue("@request", RequestTextBox.Text)
            cmd.Parameters.AddWithValue("@op_unit", Op_unitTextBox.Text)
            cmd.ExecuteNonQuery()
        End Using

        MsgBox("New Service Has Been Save", MessageBoxIcon.Information)

        cn.Close()
        Me.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    Finally
        If cn.State = ConnectionState.Open Then
            cn.Close()
        End If
    End Try
End Sub


Public Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

    'Dim iii As Integer
    Dim sqlText = "UPDATE service SET date=@date ,tech_assign=@tech_assign,err_one=@err_one,err_two= @err_two,err_tri = @err_tri,err_other = @err_other,err_other_spec = @err_other_spec,act_one = @act_one,act_two = @act_two,act_other = @act_other,act_other_spec = @act_other_spec,request = @request,op_unit = @op_unit WHERE serv_Id= @serv_Id"

    Try
        Using localCN = New SqlConnection("Data Source=(LocalDB)\v11.0;AttachDbFilename=c:\Users\Carlo\Documents\Visual Studio 2013\Projects\WindowsApplication5\WindowsApplication5\db.mdf;Integrated Security=True")
            Using localCMD = New SqlCommand(sqlText, localCN)
                localCN.Open()
                localCMD.Parameters.Add("@date", SqlDbType.Date).Value = DateDateTimePicker.Value
                localCMD.Parameters.Add("@tech_assign", SqlDbType.NVarChar).Value = Tech_assignTextBox.Text
                localCMD.Parameters.Add("@err_one", SqlDbType.Bit).Value = Err_oneCheckBox.CheckState
                localCMD.Parameters.Add("@err_two", SqlDbType.Bit).Value = Err_twoCheckBox.CheckState
                localCMD.Parameters.Add("@err_tri", SqlDbType.Bit).Value = Err_triCheckBox.CheckState
                localCMD.Parameters.Add("@err_other", SqlDbType.Bit).Value = Err_otherCheckBox.CheckState
                localCMD.Parameters.Add("@err_other_spec", SqlDbType.NVarChar).Value = Err_other_specTextBox.Text
                localCMD.Parameters.Add("@act_one", SqlDbType.Bit).Value = Act_oneCheckBox.CheckState
                localCMD.Parameters.Add("@act_two", SqlDbType.Bit).Value = Act_twoCheckBox.CheckState
                localCMD.Parameters.Add("@act_other", SqlDbType.Bit).Value = Act_otherCheckBox.CheckState
                localCMD.Parameters.Add("@act_other_spec", SqlDbType.NVarChar).Value = Act_other_specTextBox.Text
                localCMD.Parameters.Add("@request", SqlDbType.NVarChar).Value = RequestTextBox.Text
                localCMD.Parameters.Add("@op_unit", SqlDbType.NVarChar).Value = Op_unitTextBox.Text
                localCMD.Parameters.Add("@serv_Id", SqlDbType.Int).Value = i
                localCMD.ExecuteNonQuery()
                localCN.Close()
            End Using
        End Using

        'If iii <> 0 Then
        'MsgBox("The Record Has Been Updated!", MessageBoxIcon.Information)
        'Else
        'MsgBox("The Record Is Not Updated!", MessageBoxIcon.Error)
        'End If

    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub


Private Sub form3_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
        Form2.shwService()
End Sub

结束类

我的第一个问题出现同样的问题，

Answer 1

除非确实有必要，否则不要使用全局变量。在您的情况下，无需保留全局连接对象和全局命令对象。如果您在本地声明变量，您不会失去任何性能点。拥有一个全局 SqlCommand 对象意味着一旦分配的参数在您第二次进入此代码块时仍然存在。相反，本地对象总是被重新创建为新对象，并且没有先前调用的残余。
相反，应尽快释放 SqlConnection 实例，以释放本地计算机和服务器上的系统资源。

所以你的第二个问题可以这样解决

Public Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Dim iii As Integer

    Dim sqlText = "UPDATE service SET date=@date, ......"
    Try
        Using localCN = new SqlConnection (.... your connection string....)
        Using localCMD = new SqlCommand(sqlText, localCN)
             localCN.Open()
             localCMD.Parameters.Add("@date", SqlDbType.DateTime).Value =  DateDateTimePicker.Date
             .....
        End Using
        End Using
    Catch ex as Exception
         MsgBox(ex.Message)
         ' No need to add a Finally (Using statement close and dispose for you)
    End Try

第一个问题很可能是由于在调用时没有与您的变量 i 匹配的 Serv_ID 字段的记录，另一种可能是您正在使用不同的比您计划使用的数据库。特别是当您在连接字符串中使用|DataDirectory| 替换字符串时，这种情况经常发生

编辑
看你的更新，好像你有这个倒置

Public Sub getId(ByVal into As Integer)
    ' into = i
    i = into
End Sub