Question

我有后续的LINQ查询：

var queryEvents = (from p in db.cl_contact_event
                   where p.time_of_contact >= beginDate && p.time_of_contact < endDate
                   group p by p.contact_list_name into g
                   select new PenRawModel
                   {
                        listName           = g.Key,
                        download           = g.Max(a => a.total_number_of_records),
                        dials              = g.Where(a => a.ov_dial_start_time != null).Count(), //This fails.
                        //dials              = g.Sum(a => a.ov_dial_start_time != null ? 1 : 0), //This works.
                        agentConnects      = g.Sum(a => a.ov_trunk_released_time != null ? 1 : 0),
                        abandons           = g.Sum(a => a.response_status == "DAC" || a.response_status == "DAD" ? 1 : 0),
                        rightPartyContacts = g.Sum(a => a.response_status == "PTP" || a.response_status == "RPC" ? 1 : 0),
                        promiseToPays      = g.Sum(a => a.response_status == "PTP" ? 1 : 0),
                        talkTime           = g.Sum(a => EntityFunctions.DiffSeconds(a.ov_call_connected_time, a.ov_trunk_released_time)) ?? 0,
                        wrapTime           = g.Sum(a => EntityFunctions.DiffSeconds(a.ov_trunk_released_time, a.record_released_time)) ?? 0
                   }

运行时它会给我错误：

“列前缀'Project1'与表名称或查询中使用的别名。表中未指定表 FROM子句或它有一个必须使用的相关名。“

失败的原因是：

dials = g.Where(a => a.ov_dial_start_time != null).Count(),

如果我用下面注释掉的代码替换那行代码，那么查询就可以了。我更喜欢使用.Where / .Count，因为其他人更容易破译和理解代码的意图。

任何人都可以帮我解释为什么会失败以及我可能会如何修复它？

编辑 - 以下是从失败的查询发送到 Sybase数据库的SQL：

SELECT 
1 AS [C1], 
[Project2].[contact_list_name] AS [contact_list_name], 
[Project2].[C1] AS [C2], 
[Project2].[C10] AS [C3], 
[Project2].[C2] AS [C4], 
[Project2].[C3] AS [C5], 
[Project2].[C4] AS [C6], 
[Project2].[C5] AS [C7], 
CASE WHEN ([Project2].[C6] IS NULL) THEN 0 ELSE [Project2].[C7] END AS [C8], 
CASE WHEN ([Project2].[C8] IS NULL) THEN 0 ELSE [Project2].[C9] END AS [C9]
FROM ( SELECT 
    [Project1].[C1] AS [C1], 
    [Project1].[C2] AS [C2], 
    [Project1].[C3] AS [C3], 
    [Project1].[C4] AS [C4], 
    [Project1].[C5] AS [C5], 
    [Project1].[C6] AS [C6], 
    [Project1].[C7] AS [C7], 
    [Project1].[C8] AS [C8], 
    [Project1].[C9] AS [C9], 
    [Project1].[contact_list_name] AS [contact_list_name], 
    (SELECT 
        Count([Filter2].[A1]) AS [A1]
        FROM ( SELECT 
            1 AS [A1]
            FROM [mel].[cl_contact_event] AS [Extent2]
            WHERE ((([Extent2].[time_of_contact] >= @p__linq__0) AND ([Extent2].[time_of_contact] < @p__linq__1)) AND (([Project1].[contact_list_name] = [Extent2].[contact_list_name]) OR (([Project1].[contact_list_name] IS NULL) AND ([Extent2].[contact_list_name] IS NULL)))) AND ([Extent2].[ov_dial_start_time] IS NOT NULL)
        )  AS [Filter2]) AS [C10]
    FROM ( SELECT 
        [GroupBy1].[A1] AS [C1], 
        [GroupBy1].[A2] AS [C2], 
        [GroupBy1].[A3] AS [C3], 
        [GroupBy1].[A4] AS [C4], 
        [GroupBy1].[A5] AS [C5], 
        [GroupBy1].[A6] AS [C6], 
        [GroupBy1].[A7] AS [C7], 
        [GroupBy1].[A8] AS [C8], 
        [GroupBy1].[A9] AS [C9], 
        [GroupBy1].[K1] AS [contact_list_name]
        FROM ( SELECT 
            [Filter1].[K1] AS [K1], 
            Max([Filter1].[A1]) AS [A1], 
            Sum([Filter1].[A2]) AS [A2], 
            Sum([Filter1].[A3]) AS [A3], 
            Sum([Filter1].[A4]) AS [A4], 
            Sum([Filter1].[A5]) AS [A5], 
            Sum([Filter1].[A6]) AS [A6], 
            Sum([Filter1].[A7]) AS [A7], 
            Sum([Filter1].[A8]) AS [A8], 
            Sum([Filter1].[A9]) AS [A9]
            FROM ( SELECT 
                [Extent1].[contact_list_name] AS [K1], 
                [Extent1].[total_number_of_records] AS [A1], 
                CASE WHEN ([Extent1].[ov_trunk_released_time] IS NOT NULL) THEN 1 ELSE 0 END AS [A2], 
                CASE WHEN ((N'DAC' = [Extent1].[response_status]) OR (N'DAD' = [Extent1].[response_status])) THEN 1 ELSE 0 END AS [A3], 
                CASE WHEN ((N'PTP' = [Extent1].[response_status]) OR (N'RPC' = [Extent1].[response_status])) THEN 1 ELSE 0 END AS [A4], 
                CASE WHEN (N'PTP' = [Extent1].[response_status]) THEN 1 ELSE 0 END AS [A5], 
                DATEDIFF (second, [Extent1].[ov_call_connected_time], [Extent1].[ov_trunk_released_time]) AS [A6], 
                DATEDIFF (second, [Extent1].[ov_call_connected_time], [Extent1].[ov_trunk_released_time]) AS [A7], 
                DATEDIFF (second, [Extent1].[ov_trunk_released_time], [Extent1].[record_released_time]) AS [A8], 
                DATEDIFF (second, [Extent1].[ov_trunk_released_time], [Extent1].[record_released_time]) AS [A9]
                FROM [mel].[cl_contact_event] AS [Extent1]
                WHERE ([Extent1].[time_of_contact] >= @p__linq__0) AND ([Extent1].[time_of_contact] < @p__linq__1)
            )  AS [Filter1]
            GROUP BY [K1]
        )  AS [GroupBy1]
    )  AS [Project1]
)  AS [Project2]

Answer 1

完全编辑的答案

问题最终出现在Sybex ASE提供程序的LINQ到SQL的转换中：

实体框架4.1（不应该影响bug）
用于SDK 15.7 SED＃02的Sybex ASE驱动程序（负责失败）

使用任何LINQ sintax都可以很好地呈现查询。他们可以产生不同的查询，但他们都应该工作。然而，这个提供者无法使用一些可能的sintax做正确的事。

很高兴知道：

dials = g.Where(a => a.ov_dial_start_time != null).Count(), // fails.
dials = g.Count(a => a.ov_dial_start_time != null), // also fails.
dials = g.Sum(a => a.ov_dial_start_time != null ? 1 : 0), // works.

根据OP，在AsEnumerable()过滤器之前添加Where()也可以使其正常工作。

如果您发现此数据库和提供程序出现故障，最好检查将发送到服务器的查询以查找有问题的部分并尝试替代sintax，直到问题解决。您可以使用toString()检查将发送到服务器的查询。然后你可以检查sintax，或直接在服务器中运行它，看看有什么失败。

实体框架/ LINQ错误：列前缀＆＃39; Project1＆＃39;与查询中使用的表名或别名不匹配

1 个答案: