Question

我在vb.net中执行数据读取器命令时遇到错误。它抛出处理。此字段就像您在文本框中输入员工ID一样，然后它将在数据库中捕获其他字段名称，部门。

这是我的代码

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load

Dim conn As New MySql.Data.MySqlClient.MySqlConnection

Dim strConnectionString As String =ConfigurationManager.ConnectionStrings("testConnectionString").ConnectionString

Dim sqlQuery As String = "SELECT * hr_record WHERE Emplid='" & txt1.Text & "'"

Using sqlConn As New MySqlConnection(strConnectionString)

      Using sqlComm As New MySqlCommand()

      With sqlComm

        .CommandText = sqlQuery

          End With

              Try
                  sqlConn.Open()

                    Dim sqlReader As MySqlDataReader = sqlComm.ExecuteReader()

                    While sqlReader.Read()

                        txt1.Text = sqlReader("Emplid").ToString()

                        TextBox1.Text = sqlReader("Nama").ToString()

                        TextBox2.Text = sqlReader("DeptDesc").ToString()

                    End While

                Catch ex As MySqlException

                    MessageBox.Show(ex.Message)
                End Try

            End Using

        End Using

    End Sub

Answer 1

尝试更改您的选择查询，例如

Dim sqlQuery As String = "SELECT * from hr_record WHERE Emplid='" & txt1.Text & "'"

注意： - 无法使用Page_Load中的代码。尝试创建一个函数并从Page_Load调用该函数并始终使用Parameterized query。 < / p>

更新回答：

<强>的Page_Load

 Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
 DataBind()
 End Sub

外部方法：

Public Sub DataBind()
Dim sConnection As String = "server=(local);uid=sa;pwd=PassWord;database=DatabaseName"
    Using Con As New MySqlConnection(sConnection)
        Con.Open()
        Using Com As New MySqlCommand("SELECT * from hr_record WHERE Emplid='"txt1.Text
        "'", Con)
            Using RDR = Com.ExecuteReader()
                If RDR.HasRows Then
                    Do While RDR.Read
                    txt1.Text = RDR.Item("Emplid").ToString()
                    TextBox1.Text = RDR.Item("Nama").ToString()
                    TextBox2.Text = RDR.Item("DeptDesc").ToString()
                    Loop
                End If
            End Using
        End Using
        Con.Close()
    End Using
End Sub

注意：尝试实现这样的逻辑，并根据您的要求进行修改。

希望它有效。

Answer 2

你试图在页面加载中获得Emplid，但你仍然应该使用按钮检查Emplid是否存在

Answer 3

感谢所有感谢帮助我..最终这个代码感谢所有人。这个代码将是函数

 Dim conn As New MySql.Data.MySqlClient.MySqlConnection

 Dim strConnectionString As String = ConfigurationManager.ConnectionStrings("testConnectionString").ConnectionString


    Using sqlConn As New MySqlConnection(strConnectionString)
        sqlConn.Open()
        Using sqlComm As New MySqlCommand()

            sqlComm.Connection = sqlConn
            With sqlComm


                .CommandText = "SELECT * from hr_record WHERE Emplid='" & txt1.Text & "'"


            End With

            Try


                Dim sqlReader As MySqlDataReader = sqlComm.ExecuteReader()

                While sqlReader.Read()

                    txt1.Text = sqlReader("Emplid").ToString()

                    TextBox1.Text = sqlReader("Nama").ToString()

                    txtdep.Text = sqlReader("DeptDesc").ToString()

                End While

            Catch ex As MySqlException

                MessageBox.Show(ex.Message)
            End Try
            sqlConn.Close()
        End Using

    End Using

End Sub

在vb.net中获取Data Reader的错误

3 个答案: