封装数据库操作，并且提供事务处理。

使用DbProviderFactories的数据库操作类

Imports System.Data

Imports System.Configuration

Imports System.Data.Common

'*******************************************************************

'* Page/Class Name：XPDBHelper.vb

'* Title：使用DbProviderFactories的数据库操作类

'* Description：简单三层结构数据库操作类

'* Copyright：

'* Company：

'* @author：Owen,Yuan

'* Create Date：2010/3/9 14:04:56

'* Last Modifier：

'* Last Modify Date：

'*******************************************************************

Public Class XPDBHelper

'取得连接字符串中的数据库驱动提供者

Private Shared dbProviderName As String = ConfigurationManager.ConnectionStrings("ConnectionString").ProviderName

'取得数据库连接字符串

Private Shared dbConnectionString As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString

'数据库连接。

Private connection As DbConnection

Public Sub New()

Me.connection = CreateConnection(XPDBHelper.dbConnectionString)

End Sub

Public Sub New(ByVal connectionString As String)

Me.connection = CreateConnection(connectionString)

End Sub

'创建数据库连接

Public Shared Function CreateConnection() As DbConnection

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(dbProviderName)

Dim dbconn As DbConnection = dbfactory.CreateConnection()

dbconn.ConnectionString = XPDBHelper.dbConnectionString

Return dbconn

End Function

'创建数据库连接

Public Shared Function CreateConnection(ByVal connectionString As String) As DbConnection

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(dbProviderName)

Dim dbconn As DbConnection = dbfactory.CreateConnection()

dbconn.ConnectionString = connectionString

Return dbconn

End Function

'根据存储过程创建DbCommand

Public Function GetStoredProcCommond(ByVal storedProcedure As String) As DbCommand

Dim dbCommand As DbCommand = connection.CreateCommand()

dbCommand.CommandText = storedProcedure

dbCommand.CommandType = CommandType.StoredProcedure

Return dbCommand

End Function

'根据SQL语句创建DbCommand

Public Function GetSqlStringCommond(ByVal sqlQuery As String) As DbCommand

Dim dbCommand As DbCommand = connection.CreateCommand()

dbCommand.CommandText = sqlQuery

dbCommand.CommandType = CommandType.Text

Return dbCommand

End Function

#Region "增加参数"

Public Sub AddParameterCollection(ByVal cmd As DbCommand, ByVal dbParameterCollection As DbParameterCollection)

For Each dbParameter As DbParameter In dbParameterCollection

cmd.Parameters.Add(dbParameter)

Next

End Sub

Public Sub AddOutParameter(ByVal cmd As DbCommand, ByVal parameterName As String, ByVal dbType As DbType, ByVal size As Integer)

Dim dbParameter As DbParameter = cmd.CreateParameter()

dbParameter.DbType = dbType

dbParameter.ParameterName = parameterName

dbParameter.Size = size

dbParameter.Direction = ParameterDirection.Output

cmd.Parameters.Add(dbParameter)

End Sub

Public Sub AddInParameter(ByVal cmd As DbCommand, ByVal parameterName As String, ByVal dbType As DbType, ByVal value As Object)

Dim dbParameter As DbParameter = cmd.CreateParameter()

dbParameter.DbType = dbType

dbParameter.ParameterName = parameterName

dbParameter.Value = value

dbParameter.Direction = ParameterDirection.Input

cmd.Parameters.Add(dbParameter)

End Sub

Public Sub AddReturnParameter(ByVal cmd As DbCommand, ByVal parameterName As String, ByVal dbType As DbType)

Dim dbParameter As DbParameter = cmd.CreateParameter()

dbParameter.DbType = dbType

dbParameter.ParameterName = parameterName

dbParameter.Direction = ParameterDirection.ReturnValue

cmd.Parameters.Add(dbParameter)

End Sub

Public Function GetParameter(ByVal cmd As DbCommand, ByVal parameterName As String) As DbParameter

Return cmd.Parameters(parameterName)

End Function

#End Region

#Region "执行"

'执行DbCommand，返回DataSet

Public Function ExecuteDataSet(ByVal cmd As DbCommand) As DataSet

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(dbProviderName)

Dim dbDataAdapter As DbDataAdapter = dbfactory.CreateDataAdapter()

dbDataAdapter.SelectCommand = cmd

Dim ds As DataSet = New DataSet()

dbDataAdapter.Fill(ds)

Return ds

End Function

'执行DbCommand，返回DataTable

Public Function ExecuteDataTable(ByVal cmd As DbCommand) As DataTable

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(dbProviderName)

Dim dbDataAdapter As DbDataAdapter = dbfactory.CreateDataAdapter()

dbDataAdapter.SelectCommand = cmd

Dim dataTable As DataTable = New DataTable()

dbDataAdapter.Fill(dataTable)

Return dataTable

End Function

'执行DbCommand，返回DbDataReader

Public Function ExecuteReader(ByVal cmd As DbCommand) As DbDataReader

cmd.Connection.Open()

Dim reader As DbDataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)

cmd.Connection.Close()

Return reader

End Function

Public Function ExecuteNonQuery(ByVal cmd As DbCommand) As Integer

cmd.Connection.Open()

Dim ret As Integer = cmd.ExecuteNonQuery()

cmd.Connection.Close()

Return ret

End Function

Public Function ExecuteScalar(ByVal cmd As DbCommand) As Object

cmd.Connection.Open()

Dim ret As Object = cmd.ExecuteScalar()

cmd.Connection.Close()

Return ret

End Function

#End Region

#Region "执行事务"

Public Function ExecuteDataSet(ByVal cmd As DbCommand, ByVal t As XPTransaction) As DataSet

cmd.Connection = t.DbConnection

cmd.Transaction = t.DbTransact

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(XPDBHelper.dbProviderName)

Dim dbDataAdapter As DbDataAdapter = dbfactory.CreateDataAdapter()

dbDataAdapter.SelectCommand = cmd

Dim ds As DataSet = New DataSet()

dbDataAdapter.Fill(ds)

Return ds

End Function

Public Function ExecuteDataTable(ByVal cmd As DbCommand, ByVal t As XPTransaction) As DataTable

cmd.Connection = t.DbConnection

cmd.Transaction = t.DbTransact

Dim dbfactory As DbProviderFactory = DbProviderFactories.GetFactory(XPDBHelper.dbProviderName)

Dim dbDataAdapter As DbDataAdapter = dbfactory.CreateDataAdapter()

dbDataAdapter.SelectCommand = cmd

Dim dataTable As DataTable = New DataTable()

dbDataAdapter.Fill(dataTable)

Return dataTable

End Function

Public Function ExecuteReader(ByVal cmd As DbCommand, ByVal t As XPTransaction) As DbDataReader

cmd.Connection.Close()

cmd.Connection = t.DbConnection

cmd.Transaction = t.DbTransact

Dim reader As DbDataReader = cmd.ExecuteReader()

Return reader

End Function

Public Function ExecuteNonQuery(ByVal cmd As DbCommand, ByVal t As XPTransaction) As Integer

cmd.Connection.Close()

cmd.Connection = t.DbConnection

cmd.Transaction = t.DbTransact

Return cmd.ExecuteNonQuery()

End Function

Public Function ExecuteScalar(ByVal cmd As DbCommand, ByVal t As XPTransaction) As Object

cmd.Connection.Close()

cmd.Connection = t.DbConnection

cmd.Transaction = t.DbTransact

Return cmd.ExecuteScalar()

End Function

#End Region

End Class

简单三层结构数据库事务处理类

Imports System.Data

Imports System.Data.Common

'*******************************************************************

'* Page/Class Name：XPTransaction.vb

'* Title：数据库事务处理类

'* Description：简单三层结构数据库事务处理类

'* Copyright：

'* Company：

'* @author：Owen,Yuan

'* Create Date：2010/3/22 10:44:20

'* Last Modifier：

'* Last Modify Date：

'*******************************************************************

Public Class XPTransaction

Implements IDisposable

Private conn As DbConnection

Private dbTrans As DbTransaction

Public Property DbConnection() As DbConnection

Get

Return Me.conn

End Get

Set(ByVal Value As DbConnection)

Me.conn = Value

End Set

End Property

Public Property DbTransact() As DbTransaction

Get

Return Me.dbTrans

End Get

Set(ByVal Value As DbTransaction)

Me.dbTrans = Value

End Set

End Property

Public Sub New()

conn = XPDBHelper.CreateConnection()

conn.Open()

dbTrans = conn.BeginTransaction()

End Sub

Public Sub New(ByVal connectionString As String)

conn = XPDBHelper.CreateConnection(connectionString)

conn.Open()

dbTrans = conn.BeginTransaction()

End Sub

Public Sub Commit()

dbTrans.Commit()

Me.Colse()

End Sub

Public Sub RollBack()

dbTrans.Rollback()

Me.Colse()

End Sub

Public Sub Colse()

If conn.State = ConnectionState.Open Then

conn.Close()

End If

End Sub

Private disposedValue As Boolean = False ' 检测冗余的调用

' IDisposable

Protected Overridable Sub Dispose(ByVal disposing As Boolean)

If Not Me.disposedValue Then

If disposing Then

conn.Close()

' TODO: 释放其他状态(托管对象)。

End If

conn = Nothing

dbTrans = Nothing

' TODO: 释放您自己的状态(非托管对象)。

' TODO: 将大型字段设置为 null。

End If

Me.disposedValue = True

End Sub

#Region " IDisposable Support "

' Visual Basic 添加此代码是为了正确实现可处置模式。

Public Sub Dispose() Implements IDisposable.Dispose

' 不要更改此代码。请将清理代码放入上面的 Dispose(ByVal disposing As Boolean) 中。

Dispose(True)

GC.SuppressFinalize(Me)

End Sub

#End Region

End Class