服务器发布WebService返回DataTable

[WebMethod]
public DataTable GetDBTable(string strSql)
{
DataTable dt = new DataTable("default");
string sqlConnStr = this.ConnectionString;
OracleConnection conn = new OracleConnection(sqlConnStr);
using (conn)
{
try
{
conn.Open();
OracleDataAdapter myDataAdapter = new OracleDataAdapter(strSql, conn);
myDataAdapter.Fill(dt);
return dt;
}
catch (Exception e)
{
return null;
}
}
}

public static DataTable GetDBTable(string strSql)
{
try
{
localhost.Service1 sc = new localhost.Service1();
sc.Url = curURL;
return sc.GetDBTable(strSql);
}
catch(Exception ee)
{
return null;
}
}