Question

public bool AddEntity（int parentId，string description） { 尝试 { _connection.Open（）; SqlCommand command = new SqlCommand（“INSERT Structure（Path，Description）”+ “VALUES（”+ GetPath（parentId）+“。GetDescendant（”+ GetLastChildPath（parentId，1）+“，NULL），”+ description +“）”，_ connectction）;

            if (command.ExecuteNonQuery() <= 0) _success = false;

            command.Connection.Close();

            if (_success)
            {
                return true;
            }

            throw new Exception("An error has occured whilst trying to add a entity");
        }
        catch (Exception ex)
        {
            AddError(new ErrorModel("An error has occured whilst trying to add a entity", ErrorHelper.ErrorTypes.Critical, ex));
            return false;
        }
    }

上面的示例中是否有更好的方法来处理异常？

提前感谢您的帮助。

克莱尔

Answer 1

这里有很多不妥之处。

一个。您正在使用内联SQL并注入我只能假设用户生成的数据。这是一种安全风险。使用parameterised query。

湾您的异常处理是正常的，但如果发生错误，这将使连接保持打开状态。我会这样写：

 public bool AddEntity(int parentId, string description)
 {
    try
    {
        //Assuming you have a string field called connection string
        using(SqlConnection conn = new SqlConnection(_connectionString))
        {
            SqlParameter descriptionParam = new SqlParameter("@description", SqlDbType.VarChar, 11);
            descriptionParam.Value = description;

            SqlParameter parentIdParam = new SqlParameter("@parentId", SqlDbType.Int, 4);
            parentIdParam.Value = parentId;

            //Bit confused about the GetPath bit.
            SqlCommand command = new SqlCommand("INSERT Structure (Path,Description) " +
                                            "VALUES(" + GetPath(parentId) + ".GetDescendant(" + GetLastChildPath(parentId, 1) + ", NULL),@description)", conn);

            command.Parameters.Add(descriptionParam);

            if (command.ExecuteNonQuery() <= 0) _success = false;
        }

        if (_success)
        {
            return true;
        }

        //This isn't really an exception. You know an error has a occured handle it properly here.
        throw new Exception("An error has occured whilst trying to add a entity");
    }
    catch (Exception ex)
    {
        AddError(new ErrorModel("An error has occured whilst trying to add a entity", ErrorHelper.ErrorTypes.Critical, ex));
        return false;
    }

Answer 2

您可以利用IDisposable接口和using阻止功能。

using(var connection = new Connection()) // Not sure what _connection is, in this method, so making pseudo-code
{
  // ... work with connection
}

即使抛出异常，也会关闭连接。它变成（或多或少）这个：

var connection = new Connection();

try
{
  // ... work with connection
}
finally
{
  connection.Dispose();
}

在这种情况下，处理将关闭连接。

异常处理 - 有更好的方法吗？

2 个答案: