WebService return no data?

when finished, i try to use webservice as the provider, and there is no any exception throwed but it can't return any data? the insert method act correctly. the data has into the DB. But still can't no give the data list?

and nothing is changed except to uncomment the webservice provider in the web.config!

the respone as following , the main meaning is about the 'LIN-MASTER\ASPNET'  user login failed:

ResponseCode: 500 (Internal Server Error)
Connection:close
Content-Length:1934
Cache-Control:private
Content-Type:text/xml; charset=utf-8
Date:Tue, 20 Feb 2007 11:56:22 GMT
Server:Microsoft-IIS/5.1
X-AspNet-Version:2.0.50727
X-Powered-By:ASP.NET

<?xml version="1.0" encoding="utf-16"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <soap:Body>
    <soap:Fault>
      <faultcode>soap:Server</faultcode>
      <faultstring>System.Web.Services.Protocols.SoapException: 服务器无法处理请求。 ---&gt; System.Data.SqlClient.SqlException: 用户 'LIN-MASTER\ASPNET' 登录失败。
   在 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
   在 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
   在 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   在 System.Data.SqlClient.SqlConnection.Open()
   在 Microsoft.Practices.EnterpriseLibrary.Data.Database.OpenConnection()
   在 Microsoft.Practices.EnterpriseLibrary.Data.Database.ExecuteReader(DbCommand command)
   在 football.Data.Utility.ExecuteReader(Database database, DbCommand dbCommand) 位置 G:\网站\足球综合站\testNettiers\football.Data\Utility.cs:行号 357
   在 football.Data.SqlClient.SqlAdvanceTypeProviderBase.GetAll(TransactionManager transactionManager, Int32 start, Int32 pageLength, Int32&amp; count) 位置 G:\网站\足球综合站\testNettiers\football.Data.SqlClient\SqlAdvanceTypeProviderBase.generated.cs:行号 460
   在 football.Data.Bases.EntityProviderBaseCore`2.GetAll(Int32 start, Int32 pageLength, Int32&amp; count) 位置 G:\网站\足球综合站\testNettiers\football.Data\Bases\EntityProviderBaseCore.generated.cs:行号 131
   在 FootballServices.AdvanceTypeProvider_GetAll(Int32 start, Int32 pageLength, Int32&amp; count) 位置 c:\NetTiers\football\WebServices\FootballServices.asmx:行号 6439
   --- 内部异常堆栈跟踪的结尾 ---</faultstring>
      <detail />
    </soap:Fault>
  </soap:Body>
</soap:Envelope> 

You are using integrated security, and it looks like the ASPNET account is not able to login to your SQL Server.  When you switched to the web service, the database calls are now made on behalf of the web service, specifically the ASP.Net process.  As I see it you have several options:

1.  Add the ASPNET account as a valid user in your database

2.  Change the account that the web service is using to access the database.  You can do this by creating a separate app pool is IIS and changing the identity to something that can login to your database.

3.  Change your web.config in the web service to use a SQL login rather than integrated security.

i think you're right,

but another question: why i can use the insert method correctly but the select method can't?

Thanks!