VB.net登录-我是vb.net的新手，我仍然是学生.我正在尝试创建仅需要一个ID的登录名.我收到一个错误. [英] VB.net Login- I am new to vb.net and I am still a student. I am trying to create login which requires a an ID only. I am getting an error.

问题描述

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles SUBMITID.Click
        Dim conn As New SqlConnection(" Data Source=NALABI-HP\SQLEXPRESS;Initial Catalog=LeaveManagement;Integrated Security=True ")
        Dim comm As New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = 'Val(manid.Text)'", conn)
        Try
            comm.Connection.Open()
            Dim reader As SqlDataReader = comm.ExecuteReader()

            If reader.HasRows Then
                reader.Read()
            Else
                MessageBox.Show("Manager ID not found")
            End If
        Catch ex As Exception
            MessageBox.Show("Catching Exception")

        Finally
            comm.Connection.Close()
            End Try



    End Sub

推荐答案

在sqlcommand中尝试此代码

Try this code in sqlcommand

Dim comm As New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = 'Val(" & manid.Text & ")'"

使用哪种数据类型存储Man_ID值?
如果是字符串，请尝试以下操作:

What data type is used to store Man_ID value?
If it''s string, then try this:

Dim comm As New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = ''" & manid.Text & "''", conn)

如果是整数，请尝试以下操作:

If it''s integer, try this:

Dim comm As New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = " & manid.Text, conn)

如果Man_Id列的数据类型为String，则使用:

If Data Type OF Man_Id Column is String then use :

Dim CommandObject As SQLCommand = New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = '" & manid.Text & "'", SQLConnectionObject)

或IF数据类型为数字或整数，则使用:

Or IF Data Type is Numeric Or Int Then Use :

Dim CommandObject As SQLCommand = New SqlCommand("Select [Man_ID] from Manager where[Man_Id] = '" & Val(manid.Text) & "'", SQLConnectionObject)

希望对您有帮助. :)

I hope it will help you. :)

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