请问DataAccess有什么作用呢? 高手指教。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 Option Explicit On Option Strict OnImports SystemImports System.DataImports System.Windows.FormsImports Microsoft.VisualBasic'DataAccess 类'实现(插入、更新、删除、执行事务等)数据访问操作Public Class clsDataAccess '私有字段 - ADO.Net数据访问对象 Private m_objSqlCommand As System.Data.OleDb.OleDbCommand = Nothing Private m_objSqlDataAdapter As System.Data.OleDb.OleDbDataAdapter = Nothing Private m_objSqlTransaction As System.Data.OleDb.OleDbTransaction = Nothing '私有字段 - 数据连接源 Private m_strConnectionSource As String = "" '私有字段 - 查询超时 Private m_intSqlTimeOut As Integer = 0 '私有字段 - 出错信息 Private m_strErrMsg As String = "" '私有方法 - 获取应用程序根路径 Private Function m_funGetAppRootPath() As String Dim strAppRootPath As String = Application.StartupPath If Right(strAppRootPath, 1) = "\" Then Return strAppRootPath Else Return strAppRootPath & "\" End If End Function '标准构造函数1 - 使用连接字符串 Public Sub New(ByVal strConnectionString As String, ByVal intTimeOut As Integer) Me.DbConnection = New OleDb.OleDbConnection Me.DbRecordset = New DataSet Try Me.m_intSqlTimeOut = intTimeOut Me.m_strConnectionSource = strConnectionString.Trim() Me.DbConnection.ConnectionString = Me.m_strConnectionSource Me.DbConnection.Open() Catch objErr As Exception Me.m_strErrMsg = "初始化失败,参数提供的连接字符串无效!" & vbNewLine & _ "[描述信息]:" & objErr.Message & vbCrLf & _ "[错误来源]:" & objErr.Source & vbCrLf & _ "[堆栈信息]:" & objErr.StackTrace Throw New Exception(Me.m_strErrMsg) Finally Me.DbConnection.Close() End Try End Sub '标准构造函数2 - 使用 UDL 连接文件 Public Sub New(ByVal strUdlFileName As String, ByVal blnUseLocalPath As Boolean, ByVal intTimeOut As Integer) Me.DbConnection = New OleDb.OleDbConnection Me.DbRecordset = New DataSet Me.m_strConnectionSource = "FILE NAME=" If blnUseLocalPath = True Then Me.m_strConnectionSource &= Me.m_funGetAppRootPath() & strUdlFileName.Trim() Else Me.m_strConnectionSource &= strUdlFileName.Trim() End If Try Me.m_intSqlTimeOut = intTimeOut Me.DbConnection.ConnectionString = Me.m_strConnectionSource Me.DbConnection.Open() Catch objErr As Exception Me.m_strErrMsg = "初始化失败,参数提供的Udl连接文件无效!" & vbNewLine & _ "[描述信息]:" & objErr.Message & vbCrLf & _ "[错误来源]:" & objErr.Source & vbCrLf & _ "[堆栈信息]:" & objErr.StackTrace Throw New Exception(Me.m_strErrMsg) Finally Me.DbConnection.Close() End Try End Sub '公有字段 - ADO.Net连接对象 Public DbConnection As System.Data.OleDb.OleDbConnection = Nothing '公有字段 - ADO.Net数据集对象 Public DbRecordset As System.Data.DataSet = Nothing '公有只读属性 - 数据连接源 Public ReadOnly Property ConnectionSource() As String Get Return Me.m_strConnectionSource.Trim() End Get End Property '公有读写属性 - Sql超时 Public Property SqlTimeOut() As Integer Get Return Me.m_intSqlTimeOut End Get Set(ByVal intValue As Integer) Me.m_intSqlTimeOut = intValue End Set End Property '公有方法 - 获得条件参数指定的数据集 Public Sub GetDataRecordset(ByVal strDataSource As String, ByVal strDataTableName As String, _ Optional ByVal strSelectList As String = "*", Optional ByVal blnDistinct As Boolean = False, _ Optional ByVal strProtasis As String = "", Optional ByVal strGroupList As String = "", _ Optional ByVal strOrderList As String = "", Optional ByVal blnOrderASC As Boolean = True) Dim strSqlSelect As String = "SELECT " & Convert.ToString(IIf(blnDistinct = True, "DISTINCT ", "")) & strSelectList.Trim() & _ " FROM " & strDataSource.Trim() & _ Convert.ToString(IIf(strProtasis = "", "", " WHERE " & strProtasis.Trim())) & _ Convert.ToString(IIf(strGroupList = "", "", " GROUP BY " & strGroupList.Trim())) & _ Convert.ToString(IIf(strOrderList = "", "", " ORDER BY " & strOrderList.Trim())) & _ Convert.ToString(IIf(blnOrderASC = True, " ASC", " DESC")) VB调用动态库的问题 msgbox中如何加使用title标题?有例! 请问视频共享站,会员在上传视频时,往往需要下载视频上传控件,这个传输是基于那种协议的传输? 如何用用实现“放弃”、“恢复”的操作.或者提供个类似的算法.谢谢! VB用控件能实现趋势图(X轴表示时间,Y轴表示数据)吗? 如何用VB读取文件的属性资料? 判断记录个数的问题,谢谢指教! Activereport的bug????? 那位大虾救俺一命? 固定值进行随机抽取怎么做啊。。。 关于编码问题:请高人指点@@ 这样打印的乘法口诀表
Option Explicit On
Option Strict OnImports System
Imports System.Data
Imports System.Windows.Forms
Imports Microsoft.VisualBasic
'DataAccess 类
'实现(插入、更新、删除、执行事务等)数据访问操作
Public Class clsDataAccess '私有字段 - ADO.Net数据访问对象
Private m_objSqlCommand As System.Data.OleDb.OleDbCommand = Nothing
Private m_objSqlDataAdapter As System.Data.OleDb.OleDbDataAdapter = Nothing
Private m_objSqlTransaction As System.Data.OleDb.OleDbTransaction = Nothing '私有字段 - 数据连接源
Private m_strConnectionSource As String = "" '私有字段 - 查询超时
Private m_intSqlTimeOut As Integer = 0 '私有字段 - 出错信息
Private m_strErrMsg As String = ""
'私有方法 - 获取应用程序根路径
Private Function m_funGetAppRootPath() As String Dim strAppRootPath As String = Application.StartupPath If Right(strAppRootPath, 1) = "\" Then
Return strAppRootPath
Else
Return strAppRootPath & "\"
End If End Function
'标准构造函数1 - 使用连接字符串
Public Sub New(ByVal strConnectionString As String, ByVal intTimeOut As Integer) Me.DbConnection = New OleDb.OleDbConnection
Me.DbRecordset = New DataSet Try
Me.m_intSqlTimeOut = intTimeOut
Me.m_strConnectionSource = strConnectionString.Trim()
Me.DbConnection.ConnectionString = Me.m_strConnectionSource
Me.DbConnection.Open() Catch objErr As Exception
Me.m_strErrMsg = "初始化失败,参数提供的连接字符串无效!" & vbNewLine & _
"[描述信息]:" & objErr.Message & vbCrLf & _
"[错误来源]:" & objErr.Source & vbCrLf & _
"[堆栈信息]:" & objErr.StackTrace
Throw New Exception(Me.m_strErrMsg) Finally
Me.DbConnection.Close()
End Try End Sub
'标准构造函数2 - 使用 UDL 连接文件
Public Sub New(ByVal strUdlFileName As String, ByVal blnUseLocalPath As Boolean, ByVal intTimeOut As Integer) Me.DbConnection = New OleDb.OleDbConnection
Me.DbRecordset = New DataSet Me.m_strConnectionSource = "FILE NAME="
If blnUseLocalPath = True Then
Me.m_strConnectionSource &= Me.m_funGetAppRootPath() & strUdlFileName.Trim()
Else
Me.m_strConnectionSource &= strUdlFileName.Trim()
End If Try
Me.m_intSqlTimeOut = intTimeOut
Me.DbConnection.ConnectionString = Me.m_strConnectionSource
Me.DbConnection.Open() Catch objErr As Exception
Me.m_strErrMsg = "初始化失败,参数提供的Udl连接文件无效!" & vbNewLine & _
"[描述信息]:" & objErr.Message & vbCrLf & _
"[错误来源]:" & objErr.Source & vbCrLf & _
"[堆栈信息]:" & objErr.StackTrace
Throw New Exception(Me.m_strErrMsg) Finally
Me.DbConnection.Close()
End Try End Sub
'公有字段 - ADO.Net连接对象
Public DbConnection As System.Data.OleDb.OleDbConnection = Nothing
'公有字段 - ADO.Net数据集对象
Public DbRecordset As System.Data.DataSet = Nothing
'公有只读属性 - 数据连接源
Public ReadOnly Property ConnectionSource() As String Get
Return Me.m_strConnectionSource.Trim()
End Get End Property
'公有读写属性 - Sql超时
Public Property SqlTimeOut() As Integer Get
Return Me.m_intSqlTimeOut
End Get Set(ByVal intValue As Integer)
Me.m_intSqlTimeOut = intValue
End Set End Property
'公有方法 - 获得条件参数指定的数据集
Public Sub GetDataRecordset(ByVal strDataSource As String, ByVal strDataTableName As String, _
Optional ByVal strSelectList As String = "*", Optional ByVal blnDistinct As Boolean = False, _
Optional ByVal strProtasis As String = "", Optional ByVal strGroupList As String = "", _
Optional ByVal strOrderList As String = "", Optional ByVal blnOrderASC As Boolean = True) Dim strSqlSelect As String = "SELECT " & Convert.ToString(IIf(blnDistinct = True, "DISTINCT ", "")) & strSelectList.Trim() & _
" FROM " & strDataSource.Trim() & _
Convert.ToString(IIf(strProtasis = "", "", " WHERE " & strProtasis.Trim())) & _
Convert.ToString(IIf(strGroupList = "", "", " GROUP BY " & strGroupList.Trim())) & _
Convert.ToString(IIf(strOrderList = "", "", " ORDER BY " & strOrderList.Trim())) & _
Convert.ToString(IIf(blnOrderASC = True, " ASC", " DESC"))