求教C#大神，“System.Exception”异常

Question

“System.Exception”类型的未经处理的异常在 DBUtility.dll 中发生

其他信息: 在与 SQL Server 建立连接时出现与网络相关的或特定于实例的错误。未找到或无法访问服务器。请验证实例名称是否正确并且 SQL Server 已配置为允许远程连接。 (provider: 命名管道提供程序, error: 40 - 无法打开到 SQL Server 的连接)

代码：
public static DataSet Query(string SQLString)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
finally
{

connection.Close();
}
return ds;
}
}
public static DataSet myQuery(string SQLString)
{
using ( SqlConnection connection = new SqlConnection(connectionString1) )
{
DataSet ds = new DataSet();
try
{
connection.Open();
SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
}
catch ( System.Data.SqlClient.SqlException ex )
{
//throw new Exception(ex.Message);
}
finally
{
connection.Close();
}
return ds;
}
}

    public static DataSet Query(string SQLString, int Times)
    {
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            DataSet ds = new DataSet();
            try
            {
                connection.Open();
                SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                command.SelectCommand.CommandTimeout = Times;
                command.Fill(ds, "ds");
            }
            catch (System.Data.SqlClient.SqlException ex)
            {
                throw new Exception(ex.Message);
            }
            finally
            {                    
                connection.Close();
            }
            return ds;
        }
    }

Answer 1

http://www.cnblogs.com/xpxu/archive/2010/01/29/1659476.html