Question

我正在使用一个查询，该查询撤回了大量已填充的导航属性。基本上它看起来像这样：

using( var context = new MyApplicationContext() )
{
    DbSet<BaseTable> dbSet = context.Set<BaseTable>();
    IQueryable<BaseTable> query = dbSet;

    query = query.Include(entity => entity.T.C);
    query = query.Include(entity => entity.TC.Select(tc => tc.T.M));
    query = query.Include(entity => entity.TC);
    query = query.Include(entity => entity.W.FW.F.S);
    query = query.Include(entity => entity.W.FW.P);
    query = query.Include(entity => entity.W.PL.P);
    query = query.Include(entity => entity.W.PL);
    query = query.Include(entity => entity.W.E);
    query = query.Include(entity => entity.E);

    query = query.Where( set of conditions );

    List<BaseTable> Loaded = query.ToList();
}

但是，运行此代码会产生错误

IO操作超时
  [TimeoutException：IO操作超时]      MySql.Data.MySqlClient.TimedStream.StopTimer（）+ 168 8      MySql.Data.MySqlClient.TimedStream.Read（Byte []缓冲区，Int32偏移量，Int32计数）+148
     System.IO.BufferedStream.Read（Byte []数组，Int32偏移量，Int32计数）+262
     MySql.Data.MySqlClient.MySqlStream.ReadFully（Stream stream，Byte [] buffer，Int32 offset，Int32 count）+86
     MySql.Data.MySqlClient.MySqlStream.LoadPacket（）+110
     MySql.Data.MySqlClient.MySqlStream.ReadPacket（）+59
     MySql.Data.MySqlClient.NativeDriver.GetResult（Int32＆amp; affectedRow，Int64＆amp; insertedId）+100
     MySql.Data.MySqlClient.Driver.GetResult（Int32 statementId，Int32＆amp; affectedRows，Int64＆amp; insertedId）+54
     MySql.Data.MySqlClient.Driver.NextResult（Int32 statementId，Boolean force）+145
     MySql.Data.MySqlClient.MySqlDataReader.NextResult（）+524
     MySql.Data.MySqlClient.MySqlCommand.ExecuteReader（CommandBehavior behavior）+1939

如何让此查询有足够的时间加载？

Answer 1

您需要做的是增加命令超时属性。

在实体框架中，使用的上下文继承自DbContext。这是IObjectContextAdapter，但不包含对ObjectContext方法的轻松访问权限。因此，为了访问命令超时属性，您需要浏览DbContext的{{3}}属性。

using( var context = new MyApplicationContext() )
{
    DbSet<BaseTable> dbSet = context.Set<BaseTable>();
    IQueryable<BaseTable> query = dbSet;

   //set an increased command timeout by accessing Database property
   //on the context
   context.Database.CommandTimeout = 300;//in seconds (5 minutes)

    query = query.Include(entity => entity.T.C);
    query = query.Include(entity => entity.TC.Select(tc => tc.T.M));
    query = query.Include(entity => entity.TC);
    query = query.Include(entity => entity.W.FW.F.S);
    query = query.Include(entity => entity.W.FW.P);
    query = query.Include(entity => entity.W.PL.P);
    query = query.Include(entity => entity.W.PL);
    query = query.Include(entity => entity.W.E);
    query = query.Include(entity => entity.E);

    query = query.Where( set of conditions );

    List<BaseTable> Loaded = query.ToList();
}

现在，您的查询可以拥有所需的时间，以便在必要时提取更多数据。

Answer 2

在web.config

中的连接字符串中使用此代码

“default command timeout=0”

 "server=localhost;Database=Database;uid=;pwd=;Allow User Variables=True;Convert Zero Datetime=True;default command timeout=0"

IO操作超时

2 个答案: