.net配置文件和数据库

[lxs25451413500]

.net配置文件的内容和属性是什么？
连接数据库有几种方式?
.net连接数据库有几种方法？
.net提供数据库连接工具吗？是什么？
谢谢大家给个回答

[xunis]

Imports System.Data
Imports System.Data.Common
Imports System.Configuration
Imports System.Data.SqlClient '引用數據庫服務

Module Module1
Public g_CN As SqlConnection

Private Sub GetConnection()
Dim conn As New SqlConnection
conn.ConnectionString = ConfigurationManager.ConnectionStrings.Item("ConnectionString").ToString
conn.Open()
g_CN = conn
End Sub

Public Function GetDataSet(ByVal strSQL As String) As DataSet
Dim ds As DataSet = New DataSet '聲明數據表 Dim ds As New DataSet
Try
'初始化適配器
Dim da As SqlDataAdapter
'打開數據庫鏈接
If g_CN Is Nothing Then
GetConnection()
End If
ds.Clear()
'將數據庫和適配器鏈接在一起
da = New SqlDataAdapter(strSQL, g_CN)
'將數據放到數據集中
da.Fill(ds)
Catch ex As Exception
MsgBox("GetDataSet出错！")
End Try
Return ds
End Function

Public Function ExecuteSQL(ByVal strSQL As String) As Integer
'數據命令
Dim comm As SqlCommand = New SqlCommand()
Dim iReturn As Integer = 0
'打開數據庫鏈接
If g_CN Is Nothing Then
GetConnection()
End If
comm.Connection = g_CN
comm.CommandType = CommandType.Text
comm.CommandText = strSQL
iReturn = CInt(comm.ExecuteNonQuery.ToString)
Return iReturn
End Function


End Module

[xunis]

<connectionStrings>
		<add name="ConnectionString" connectionString="Data Source=.;Initial Catalog=DBAccess1;Persist Security Info=True;User ID=sa;Password=19861012" providerName="System.Data.SqlClient"/>
	</connectionStrings