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      VB連接MYSQL實例

       ddlld345 2012-06-22

      VB連接MYSQL實例

      電腦需安裝數(shù)據庫'mysql server'和'mysql connector net'相關版本軟件。

      在工程的‘項目’-‘添加引用’中添加引用‘mysql.data’

      實現(xiàn)代碼如下:
      Imports System.IO
      Imports System
      Imports System.Data
      Imports System.Windows.Forms
      Imports MySql.Data.MySqlClient
      Public Class Form1
          Dim conn As MySqlConnection
          Dim data As DataTable
          Dim da As MySqlDataAdapter
          Dim cb As MySqlCommandBuilder

          Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
              If Not conn Is Nothing Then conn.Close()
              Dim connStr As String
              Dim reader As MySqlDataReader
              connStr = String.Format("server={0};user id={1}; password={2}; database=mysql; pooling=false", "localhost", "root", "root")  '登錄mysql數(shù)據庫 為本機,用戶名:root 密碼:root
              Try
                  conn = New MySqlConnection(connStr)
                  conn.Open()
                  reader = Nothing
                  Dim cmd As New MySqlCommand("use db", conn)      '進入存儲數(shù)據所用的數(shù)據庫
                  reader = cmd.ExecuteReader()
                  While (reader.Read())
                  End While
                  If Not reader Is Nothing Then reader.Close()
              Catch ex As MySqlException
                  'MessageBox.Show(ex.ToString)
                  MessageBox.Show("程序出現(xiàn)錯誤!請重啟,或聯(lián)系維護人員。", "抱歉")
              Finally
                  If Not reader Is Nothing Then reader.Close()
              End Try

          End Sub

          Private Sub btnconn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnconn.Click
              Dim temp_int, int_lrow, int_rrow As Integer

              data = New DataTable
              Try
                  da = New MySqlDataAdapter("select * from db_table where name='lady_gaga'", conn)            '在相關表中查找數(shù)據 db_table 為表名,name 為列名
                  cb = New MySqlCommandBuilder(da)

                  da.Fill(data)
                  int_rrow = data.Rows.Count              '返回查找后的數(shù)據行數(shù),返回0行則表示沒有找到記錄,返回大于0行,則表示找到了相關記錄
                  If int_rrow = 0 Then
                     MessageBox.Show("無記錄")
                  Else
                       MessageBox.Show("data.Rows.Item(0).Item(3).ToString")   'Item(0).Item(3) 表示返回的第1條記錄(第一條的下標為0)中的第4列值
                  End If

              Catch ex As Exception
                  MessageBox.Show(ex.ToString)
              End Try
            
          End Sub
      End Class

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