随着信息技术的发展，各种软件系统的开发愈发重要。其中，数据库登陆系统作为一个非常重要的系统，不仅可以成功保护数据的安全性，更可以方便用户的使用。在本文中，我们将简单介绍如何使用VB.NET来制作一个数据库登陆系统。
一、数据库
我们需要选择一个数据库。在本例中，我们选择使用Microsoft Sql Server>香港服务器首选树叶云，2H2G首月10元开通。树叶云（www.IDC.Net）提供简单好用，价格厚道的香港/美国云
服务器
和独立服务器。IDC+ISP+ICP资质。ARIN和APNIC会员。成熟技术团队15年行业经验。
vb.net数据库操作
操作access数据库的一些常用方法，代码如下Imports SystemImports Class DBPrivate Shared com As Shared reader As Shared adapter As Shared conn As 获取数据库连接 Public Shared ReadOnly Property NewConn() As OleDbConnectionGetDim connectionString As StringconnectionString = (Supermarket)连接2010数据库connectionString = Provider=.12.0;Data Source=F:\连接03-07数据库connectionString = Provider=.4.0;Data Source=F:\JL\应该在这里先判断conn是否为NothingIf conn Is Nothing Thenconn = New (connectionString)End IfIf <> ()End IfReturn connEnd GetEnd Property 执行增删改(无参) 执行的Sql语句 Public Shared Function ExecuteNonQuery(ByVal sql As String) As Integercom = New (sql, NewConn())Return ()End Function 执行增删改(有参) Public Shared Function ExecuteNonQuery(ByVal sql As String, ByVal para As OleDbParameter()) As Integercom = New (sql, NewConn)(para)Return ()End Function 执行增删改的存储过程 Public Shared Function ExecuteNonQuery(ByVal para As SqlParameter(), ByVal ProcedureName As String) As IntegerDim CMD As = New () = NewConn() = = (para)Return Function 执行查询(返回一个结果集，无参) Public Shared Function GetScalar(ByVal sql As String) As StringDim> Public Shared Function GetScalar(ByVal sql As String, ByVal para As SqlParameter()) As Integercom = New (sql, NewConn)(para)Return 32(())End Function 执行查询(返回一行数据,无参) Public Shared Function GetReader(ByVal sql As String) As OleDbDataReadercom = New (sql, NewConn)reader = ()Return readerEnd Function 执行查询(返回一行数据,有参) Public Shared Function GetReader(ByVal sql As String, ByVal para As SqlParameter()) As OleDbDataReadercom = New (sql, NewConn)(para)reader = ()Return readerEnd Function 执行查询(返回一个数据集,无参) Public Shared Function GetDataSet(ByVal sql As String) As> Public Shared Function GetDataSet(ByVal sql As String, ByVal para As SqlParameter()) As DataTableDim dataset As DataSetdataset = New DataSet()com = New OleDbCommand(sql, NewConn)(para)adapter = New OleDbDataAdapter(com)(dataset)Return (0)End FunctionEnd Class
VB怎么弄数据库登陆
VB数据库登陆代码Private Sub Command1_Click() & Trim() & If & Trim() & If ThenMsgBox 请输入正确的密码, 48, 提示 = IfEnd IfEnd Sub
vb.net的数据库连接
1·绑定数据源来进行连接2.用代码连接先到数据库建立一个数据库和相应的表连接数据库的代码：Dim str As String = Data Source=服务器名;Initial Catalog=数据库名;Persist Security Info=True;User ID=;Password=dim conn As = New = ()Return TrueCatch ex As ExceptionMsgBox()Return FalseEnd Try登录代码：Dim str As String = Data Source=服务器名;Initial Catalog=数据库名;Persist Security Info=True;User ID=;Password=dim conn As = New = ()sqlstr = Select * From Amd Where AmdName= & & And AmdPwd = & & Dim sqlcmd As = New (sqlstr, conn)Dim dr As = = True Then 判断一条记录为真() 显示下个窗体() ’隐藏当前窗体(输入信息有误！, 提示) = = End If
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