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在VB.NET应用中使用MySQL的方法_MySQL

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Jun 01, 2016 pm 12:59 PM

mysqlvb

绪言

在Visual Studio中使用向导连接到MySQL数据库是一件相当棘手的事情。因为MySQL并不在VS2012默认支持的数据库中（比如SQL Server）。在本文中我将介绍如何使用VB.NET连接到MySQL数据库并且执行SQL语句（SELECT，UPDATE，DELETE），同时我会展示如何将MySQL连接器导入（connectors）到Visual Studio 2012中。

使用代码

你须要从http://dev.mysql.com/downloads/connector/下载MySQL连接器(mysql-connector-net)并导入到Visual Studio中。解压下载到的文件到指定文件夹，例如C:\。启动Visual Studio。
在VS2012创建一个新的项目，项目名称可以是你任意你喜欢的：
2015625114720396.png (1600×900)

打开project（项目） --> Add reference（添加引用）。

2015625114751470.png (1600×900)

2015625114812648.png (1600×900)

选中刚才下载的DLL文件，将其导入你的项目中。
创建一个新的VB类，命名为itmysqldbas如下所示：

2015625114834509.png (1600×900)

现在你可以直接使用我写的MySQL连接类的代码。我把这个类的代码附在了这里，或者mySqlDB.zip。
你可以把这个类的代码复制到你的类中，或者干脆你直接把这个类文件放到你的项目中，这完全取决于你的决定。无论你采用哪种方式，你都能得到一个即能连接到MySQL数据库又能执行SELECT、UPDATE、DELETE操作的类。
我将仅仅使用几行代码就添加一个简单的GridView到我的项目中，并试图从数据库中读取数据。

代码如下:

Dim mydb As New mySqlDB

    Protected Sub Page_Load(ByVal sender As Object, _
              ByVal e As System.EventArgs) Handles Me.Load
        Try
            Dim dataset As New DataSet
            Dim queryresult As String = ""
            dataset = mydb.executeSQL_dset("SELECT COMMAND", queryresult)
            GridView1.DataSource = dataset
            GridView1.DataBind()
        Catch ex As Exception

        End Try
    End Sub

当你执行上述代码时，会调用executeSQL_dset这个函数从数据库中获取数据。这个函数会返回一个数据集（dataset），然后你就能在项目中作用它了。

若要执行更新或删除命令，还有另一个方法，如下：

代码如下:

Dim dataset As New DataSet
    Dim queryresult As String = ""
    mydb.executeDMLSQL("update or delete SQL command", queryresult)
    If queryresult = "SUCCESS" Then
        'your command is ok
    Else
        'your command is not ok
    End If

希望这个篇文章对会对你有用。

MySQL非常小巧、非常容易下载，并且它是免费的（开源的）。希望你能使用上述的类连接到MySQL数据库，并能执行（SELECT,UPDATE,DELETE）命令。

我会在另一篇文章中解释这个类的一些细节上的问题，以方便你自己能修改这个类。

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