DAL层配合基类的代码记录

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这是我第二遍做机房收费系时的DAL层配合基类的代码

DAL层的代码：

Imports System.Data.SqlClient
Imports Entity

Public Class da_User

    '继承da_Base基类
    Inherits da_Base
    '连接数据库
    Private connStr As String = System.Configuration.ConfigurationSettings.AppSettings("connStr")

    ''' <summary>
    ''' 获得一个用户信息
    ''' </summary>
    ''' <param name="UserID">用户ID</param>
    ''' <returns>一个用户对象</returns>
    ''' <remarks>2011/3/22 11:27 By NOVAGang</remarks>
    Public Function GetObject(ByVal UserID As String) As Entity.user_Info

        Dim sql As String = "select * from user_Info where UserID=@UserID"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As SqlCommand = New SqlCommand(sql, conn)
        Dim sqlParam As New SqlParameter("@UserID", SqlDbType.Char)
        cmd.Parameters.Add(sqlParam)
        sqlParam.Value = UserID
        Dim sdr As SqlDataReader = Nothing
        Dim EntityUserInfo As New Entity.user_Info

        Try
            conn.Open()
            sdr = cmd.ExecuteReader()
            While sdr.Read
                EntityUserInfo.UserID = sdr.GetString(0)
                EntityUserInfo.Password = sdr.GetString(1)
                EntityUserInfo.Level = sdr.GetString(2)
                EntityUserInfo.UserName = sdr.GetString(3)
                EntityUserInfo.Head = sdr.GetString(4)
            End While
            Return EntityUserInfo
        Catch ex As Exception
            Return Nothing
        Finally
            Close(sdr)
            Close(cmd)
            Close(conn)
        End Try

    End Function

   ''' <summary>
    ''' 获得所有用户
    ''' </summary>
    ''' <returns>所有用户的DataSet集合</returns>
    ''' <remarks>2011/3/22 22:13 By NOVAGang</remarks>
    Public Function SelectAll(ByVal Level As String) As DataSet
        Dim sql As String = "select * from user_Info where Level=@Level"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As SqlCommand = New SqlCommand(sql, conn)
        Dim dap As SqlDataAdapter = New SqlDataAdapter(cmd)
        Dim ds As New DataSet

        Dim sqlParam As New SqlParameter("@Level", SqlDbType.Char)
        cmd.Parameters.Add(sqlParam)
        sqlParam.Value = Level

        Try
            conn.Open()
            dap.Fill(ds)
            Return ds
        Catch ex As Exception
            Return Nothing
        Finally
            Close(cmd)
            Close(conn)
        End Try

    End Function

''' <summary>
    ''' 删除一条用户信息
    ''' </summary>
    ''' <param name="EntityUserInfo">一个用户对象</param>
    ''' <returns>是否删除成功</returns>
    ''' <remarks>2011/3/22 22:18 By NOVAGang</remarks>
    Public Function Del(ByVal EntityUserInfo As Entity.user_Info) As Boolean
        Dim sql As String = "delete from user_Info where UserID=@UserID"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As New SqlCommand(sql, conn)
        Dim sqlParam As New SqlParameter("@UserID", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.UserID
        cmd.Parameters.Add(sqlParam)

        Try
            conn.Open()
            Return cmd.ExecuteNonQuery > 0
        Catch ex As Exception
            Return False
        Finally
            Close(cmd)
            Close(conn)
        End Try

    End Function

    ''' <summary>
    ''' 更新用户密码
    ''' </summary>
    ''' <param name="UserID">用户ID</param>
    ''' <param name="Password">用户密码</param>
    ''' <returns>更新是否成功</returns>
    ''' <remarks>2011/3/22 22:13 By NOVAGang</remarks>
    Public Function UpdatePWD(ByVal UserID As String, ByVal Password As String) As Boolean

       Dim sql As String = "update user_Info set Password=@Password where UserID=@UserID"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As SqlCommand = New SqlCommand(sql, conn)
        Dim sqlParam As SqlParameter

        sqlParam = New SqlParameter("@UserID", SqlDbType.Char)
        sqlParam.Value = UserID
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@Password", SqlDbType.Char)
        sqlParam.Value = Password
        cmd.Parameters.Add(sqlParam)

        Try
            conn.Open()
            Return cmd.ExecuteNonQuery() > 0
        Catch ex As Exception
            Return False
        Finally
            Close(cmd)
            Close(conn)
        End Try

    End Function

   ''' <summary>
    ''' 更新一条用户信息
    ''' </summary>
    ''' <param name="UserID">一个UserID字段</param>
    ''' <param name="Head">一个Head字段</param>
    ''' <returns>更新是否成功</returns>
    ''' <remarks>2011/3/22 22:23 By NOVAGang</remarks>
    Public Function Update(ByVal UserID As String, ByVal Head As String) As Boolean
        Dim sql As String = "update user_Info set Head=@Head where UserID=@UserID"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As SqlCommand = New SqlCommand(sql, conn)
        Dim sqlParam As SqlParameter

        sqlParam = New SqlParameter("@UserID", SqlDbType.Char)
        sqlParam.Value = UserID
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@Head", SqlDbType.Char)
        sqlParam.Value = Head
        cmd.Parameters.Add(sqlParam)

        Try
            conn.Open()
            Return cmd.ExecuteNonQuery() > 0
        Catch ex As Exception
            Return False
        Finally
            Close(cmd)
            Close(conn)
        End Try
    End Function

    ''' <summary>
    ''' 插入一条用户信息
    ''' </summary>
    ''' <param name="EntityUserInfo">用户信息表</param>
    ''' <returns>插入是否成功</returns>
    ''' <remarks>2011/3/22 22:13 By NOVAGang</remarks>
    Public Function Inster(ByVal EntityUserInfo As Entity.user_Info) As Boolean
        Dim sql As String = "insert into user_Info(UserID,Password,Level,UserName,Head) values (@UserID,@Password,@Level,@UserName,@Head)"
        Dim conn As SqlConnection = CreateConn(connStr)
        Dim cmd As SqlCommand = New SqlCommand(sql, conn)
        Dim sqlParam As SqlParameter

        sqlParam = New SqlParameter("@UserID", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.UserID
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@Password", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.Password
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@Level", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.Level
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@UserName", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.UserName
        cmd.Parameters.Add(sqlParam)

        sqlParam = New SqlParameter("@Head", SqlDbType.Char)
        sqlParam.Value = EntityUserInfo.Head
        cmd.Parameters.Add(sqlParam)

        Try
            conn.Open()
            Return cmd.ExecuteNonQuery() > 0
        Catch ex As Exception
            Return False
        Finally
            Close(cmd)
            Close(conn)
        End Try
    End Function

End Class

基类da_Base的代码：

Imports System.Data.SqlClient

Public Class da_Base

    ''' <summary>
    ''' 创建一个数据连接
    ''' </summary>
    ''' <param name="connStr">数据库连接字符串</param>
    ''' <returns></returns>
    ''' <remarks>2011/3/22 22:23 By NOVAGang</remarks>
    '''Private connStr As String = "Data Source=ASUS-PC;Initial Catalog=jftoll_sys;Persist Security Info=True;User ID=sa;Password=123456"    （这是没有通过配置文件直接连接数据库的写法）


    Public Function CreateConn(ByVal connStr As String) As SqlConnection
        Return New SqlConnection(connStr)
    End Function

   ''' <summary>
    ''' 关闭相关对象
    ''' </summary>
    ''' <param name="conn"></param>
    ''' <remarks>2011/3/22 22:23 By NOVAGang</remarks>
    Public Sub Close(ByVal conn As SqlConnection)
        If Not IsNothing(conn) Then
            conn.Close()
            conn = Nothing
        End If
    End Sub

    ''' <summary>
    ''' 关闭相关对象
    ''' </summary>
    ''' <param name="sdr"></param>
    ''' <remarks>2011/3/22 22:23 By NOVAGang</remarks>
    Public Sub Close(ByVal sdr As SqlDataReader)
        If Not IsNothing(sdr) Then
            sdr.Close()
            sdr = Nothing
        End If
    End Sub

    ''' <summary>
    ''' 关闭相关对象
    ''' </summary>
    ''' <param name="cmd"></param>
    ''' <remarks>2011/3/22 22:23 By NOVAGang</remarks>
    Public Sub Close(ByVal cmd As SqlCommand)
        If Not IsNothing(cmd) Then
            cmd.Dispose()
            cmd = Nothing
        End If
    End Sub
End Class