vb.net 操作Access数据库帮助类

Imports System
Imports System.Data.SqlClient
Imports System.Configuration
Imports System.Collections.Generic
Imports System.Text
Imports System.Data
Imports System.Configuration.ConfigurationSettings
Imports System.Data.OleDb

Public Class DB

Private Shared com As OleDb.OleDbCommand
Private Shared reader As OleDb.OleDbDataReader
Private Shared adapter As OleDb.OleDbDataAdapter
Private Shared conn As OleDb.OleDbConnection

''' <summary>
''' 获取数据库连接
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Shared ReadOnly Property NewConn() As OleDbConnection
Get
Dim connectionString As String
'connectionString = System.Configuration.ConfigurationSettings.GetConfig("Supermarket")
'连接2010数据库
'connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\GCU.accdb"
'连接03-07数据库
connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\JL\GCU.MDB"

'应该在这里先判断conn是否为Nothing
If conn Is Nothing Then
conn = New OleDb.OleDbConnection(connectionString)
End If
If conn.State <> ConnectionState.Open Then
conn.Open()
End If
Return conn
End Get
End Property

''' <summary>
''' 执行增删改(无参)
''' </summary>
''' <param name="sql">执行的Sql语句</param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function ExecuteNonQuery(ByVal sql As String) As Integer
com = New OleDb.OleDbCommand(sql, NewConn())
Return com.ExecuteNonQuery()
End Function

''' <summary>
''' 执行增删改(有参)
''' </summary>
''' <param name="sql"></param>
''' <param name="para"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function ExecuteNonQuery(ByVal sql As String, ByVal para As OleDbParameter()) As Integer
com = New OleDb.OleDbCommand(sql, NewConn)
com.Parameters.AddRange(para)
Return com.ExecuteNonQuery()
End Function

''' <summary>
''' 执行增删改的存储过程
''' </summary>
''' <param name="para"></param>
''' <param name="ProcedureName"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function ExecuteNonQuery(ByVal para As SqlParameter(), ByVal ProcedureName As String) As Integer
Dim cmd As OleDb.OleDbCommand
cmd = New OleDb.OleDbCommand()
cmd.Connection = NewConn()
cmd.CommandText = ProcedureName
cmd.CommandType = CommandType.StoredProcedure
cmd.Parameters.AddRange(para)
Return com.ExecuteNonQuery
End Function

''' <summary>
''' 执行查询(返回一个结果集，无参)
''' </summary>
''' <param name="sql"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetScalar(ByVal sql As String) As String
Dim dataset As DataSet
dataset = New DataSet()
com = New OleDb.OleDbCommand(sql, NewConn)
adapter = New OleDbDataAdapter(com)
adapter.Fill(dataset)
If dataset.Tables.Count > 0 And dataset.Tables(0).Rows.Count > 0 Then
Return dataset.Tables(0).Rows(0)(0).ToString()
End If
Return "Null"
End Function

''' <summary>
''' 执行查询(返回一个结果集，有参)
''' </summary>
''' <param name="sql"></param>
''' <param name="para"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetScalar(ByVal sql As String, ByVal para As SqlParameter()) As Integer
com = New OleDb.OleDbCommand(sql, NewConn)
com.Parameters.AddRange(para)
Return Convert.ToInt32(com.ExecuteScalar())
End Function

''' <summary>
''' 执行查询(返回一行数据,无参)
''' </summary>
''' <param name="sql"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetReader(ByVal sql As String) As OleDbDataReader
com = New OleDb.OleDbCommand(sql, NewConn)
reader = com.ExecuteReader()
Return reader
End Function

''' <summary>
''' 执行查询(返回一行数据,有参)
''' </summary>
''' <param name="sql"></param>
''' <param name="para"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetReader(ByVal sql As String, ByVal para As SqlParameter()) As OleDbDataReader
com = New OleDb.OleDbCommand(sql, NewConn)
com.Parameters.AddRange(para)
reader = com.ExecuteReader()
Return reader
End Function

''' <summary>
''' 执行查询(返回一个数据集,无参)
''' </summary>
''' <param name="sql"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetDataSet(ByVal sql As String) As DataTable
Dim dataset As DataSet
dataset = New DataSet()
com = New OleDb.OleDbCommand(sql, NewConn)
adapter = New OleDbDataAdapter(com)
adapter.Fill(dataset)
Return dataset.Tables(0)
End Function

''' <summary>
''' 执行查询(返回一个数据集,有参)
''' </summary>
''' <param name="sql"></param>
''' <param name="para"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetDataSet(ByVal sql As String, ByVal para As SqlParameter()) As DataTable
Dim dataset As DataSet
dataset = New DataSet()
com = New OleDbCommand(sql, NewConn)
com.Parameters.AddRange(para)
adapter = New OleDbDataAdapter(com)
adapter.Fill(dataset)
Return dataset.Tables(0)
End Function
End Class