从MySQL查看VB2010文本框上的数据 [英] Viewing Data on VB2010 Textboxes from MySQL

问题描述

我有这个添加/编辑/删除项目，我能够完成添加功能，现在我在文本框上查看数据库中的数据。事情是我还不知道为什么数据没有出现，即使我按照我的意思正确地遵循了语法形式。



这是我的代码：

I have this add/edit/delete project, I'm able to finish the adding function and now I'm on the viewing data from the database on text boxes. The thing is I don't know yet why data doesn't appear even if I have followed syntax forms correctly as I think so.

Here's the code I have:

Private Sub register_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       firstnametb.Focus()

       Call Connection()
       Try
           strSql = "SELECT * FROM add_edit_delete;"
           cmd.CommandText = strSql
           cmd.Connection = conn
           dadapter.SelectCommand = cmd

           datardr = cmd.ExecuteReader

           lastnametb.Text = datardr("LastName")
           firstnametb.Text = datardr("FirstName")
           middletb.Text = datardr("MiddleInitial")
           agetb.Text = datardr("Age")
           loctb.Text = datardr("Location")
           unametb.Text = datardr("Uname")
           pwordtb.Text = datardr("Pword")

           conn.Close()
       Catch ex As Exception

       End Try
   End Sub

MODULE：

MODULE:

Public conn As New MySqlConnection
Public cmd As New MySqlCommand
Public dadapter As New MySqlDataAdapter
Public datardr As MySqlDataReader
Public strSql As String

Public Sub Connection()
    If conn.State = ConnectionState.Closed Then
        conn.ConnectionString = "Server = localhost; User Id = root; Password = root; Database = add_edit_delete"
        conn.Open()
        MsgBox("Connected!")
    Else
        MsgBox("Not Connected!")
    End If
End Sub

我有任何错误或任何错误吗？感谢您的帮助！:)

Do I have any error or whatsoever? Thanks for any help! :)

推荐答案

是的 - 添加：

Yep - add:

If datardr.HasRows Then
	datardr.Read()

在你的ExecuteReader之后立即：

Immediately after your ExecuteReader:

 datardr = cmd.ExecuteReader

 If datardr.HasRows Then
datardr.Read()
    lastnametb.Text = datardr("LastName")
    firstnametb.Text = datardr("FirstName")
    middletb.Text = datardr("MiddleInitial")
    agetb.Text = datardr("Age")
    loctb.Text = datardr("Location")
    unametb.Text = datardr("Uname")
    pwordtb.Text = datardr("Pword")
 End If

我在将文本框与数据库匹配时遇到问题，它只读取第一行但不是表的其他行。那有什么代码？请帮助我...... :(（

这是我的代码：

Im having a problem in matching the textbox to the database, it only read the 1st line but not the other rows of the table. is there any code for that?? please help me... :((
Here's my code:

Call Connection()

        Try
            strSql = "Select * From try"
            cmd.CommandText = strSql
            cmd.Connection = conn
            dadapter.SelectCommand = cmd

            datardr = cmd.ExecuteReader

            If TextBox1.Text = "" Then
                MsgBox("Please enter your student number!")

            ElseIf datardr.HasRows Then
                datardr.Read()

                u = datardr("studno")
                TextBox1.Text = datardr("studno")

                If TextBox1.Text = u Then
                    Label1.Text = datardr("student_name")
                    Label2.Text = datardr("contact")
                    Label3.Text = datardr("guardian_contact")
                    Label4.Text = datardr("image")
                    Label5.Text = datardr("address")
                    Label6.Text = datardr("year")
                    Label7.Text = datardr("rfcourse")
                    Label8.Text = datardr("status")
                    Label9.Text = datardr("rfidno")
                End If

                conn.Close()
            End If
        Catch ex As Exception

        End Try
    End Sub

提前致谢。

Thanks in advance.

vb.net 2010的正确代码



mysqlconn =新的MySqlConnection

mysqlconn.ConnectionString =

server = HP; userid = root; password = root; database = database1

Dim READER As MySqlDataReader

Dim dadapter As New MySqlDataAdapter

尝试

mysqlconn.Open（）

Dim Query As String

Query =select * from database1.table1 where id = '&TextBox2.Text&'



COMMAND = New MySqlCommand（Query，mysqlconn）

READER = COMMAND.ExecuteReader

当READER.Read

TextBox12.Text = READER.GetString（input1）

TextBox11.Text = READER.GetString（input2）

TextBox10.Text = READER.GetString（input3）

TextBox9.Text = READER.GetString（input4）

TextBox8.Text = READER.GetString（input5）

结束时





MessageBox.Show（数据读取）

mysqlconn.Close（）

Catch ex As MySqlException

MessageBox.Show（ex.Message） ）

最后

mysqlconn.Dispose（）



结束尝试

correct code for vb.net 2010

mysqlconn = New MySqlConnection
mysqlconn.ConnectionString =
"server=HP;userid=root;password=root;database=database1"
Dim READER As MySqlDataReader
Dim dadapter As New MySqlDataAdapter
Try
mysqlconn.Open()
Dim Query As String
Query = "select * from database1.table1 where id='" & TextBox2.Text & "'"

COMMAND = New MySqlCommand(Query, mysqlconn)
READER = COMMAND.ExecuteReader
While READER.Read
TextBox12.Text = READER.GetString("input1")
TextBox11.Text = READER.GetString("input2")
TextBox10.Text = READER.GetString("input3")
TextBox9.Text = READER.GetString("input4")
TextBox8.Text = READER.GetString("input5")
End While


MessageBox.Show("Data read ")
mysqlconn.Close()
Catch ex As MySqlException
MessageBox.Show(ex.Message)
Finally
mysqlconn.Dispose()

End Try

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