INNER JOINS 和 LEFT JOINS 的 EF Core 难度

Question

我正在尝试从一个非常大的数据库中检索一些数据。 为了检索它，我需要从 6 个内部连接中获取一些数据。 以下选项是我已经尝试过的：

选项 1 使用 EF Core en ThenInclude

    var enquiry = await _context.Enquiries
        .Where(e => e.Id == id)
        .Include(e => e.EnqPartJobs.Where(ej => ej.RecordStateId == 0))
            .ThenInclude(ej => ej.AnswerGrpBatch)
                .ThenInclude(agb => agb.AnswerGrps)
                    .ThenInclude(ag => ag.EnqPropResults)
                        .ThenInclude(epr => epr.EnqPropResultDevs)
                            .ThenInclude(epr => epr.Deviation)
        .ToListAsync();

这种方法的优点是它可以很好地在带有 AnswerGrpBatches 列表的查询 class 中使用 map。 顺便说一句，我没有命名这些类，这就是数据库的外观。

查看查询时，如下所示：

SELECT [e].[SID], [e].[FK_CRMPartner_SID], [e].[FK_Certificate_SID], [e].[createDate], [e].[displayDate], [e].[extID], [e].[finishDate], [e].[fixedGenId], [e].[aName], [t2].[SID], [t2].[FK_Enquiry_SID], [t2].[aName], [t2].[FK_RecordState_SID], [t2].[remark], [t2].[validFrom], [t2].[validTo], [t2].[SID0], [t2].[FK_EnqPartJob_SID], [t2].[FK_RecordState_SID0], [t2].[SID1], [t2].[FK_AnswerGrpBatch_SID], [t2].[FK_RecordState_SID1], [t2].[SID00], [t2].[FK_AnswerGrp_SID], [t2].[FK_EnqPropertyForm_SID], [t2].[FK_PossResult_SID], [t2].[FK_RecordState_SID00], [t2].[value], [t2].[SID000], [t2].[FK_Deviation_SID], [t2].[FK_EnqPropResult_SID], [t2].[SID0000], [t2].[aDescription], [t2].[aName0]
FROM [Enquiry] AS [e]
LEFT JOIN (
    SELECT [e0].[SID], [e0].[FK_Enquiry_SID], [e0].[aName], [e0].[FK_RecordState_SID], [e0].[remark], [e0].[validFrom], [e0].[validTo], [a].[SID] AS [SID0], [a].[FK_EnqPartJob_SID], [a].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t1].[SID] AS [SID1], [t1].[FK_AnswerGrpBatch_SID], [t1].[FK_RecordState_SID] AS [FK_RecordState_SID1], [t1].[SID0] AS [SID00], [t1].[FK_AnswerGrp_SID], [t1].[FK_EnqPropertyForm_SID], [t1].[FK_PossResult_SID], [t1].[FK_RecordState_SID0] AS [FK_RecordState_SID00], [t1].[value], [t1].[SID00] AS [SID000], [t1].[FK_Deviation_SID], [t1].[FK_EnqPropResult_SID], [t1].[SID000] AS [SID0000], [t1].[aDescription], [t1].[aName] AS [aName0]
    FROM [EnqPartJob] AS [e0]
    LEFT JOIN [AnswerGrpBatch] AS [a] ON [e0].[SID] = [a].[FK_EnqPartJob_SID]
    LEFT JOIN (
        SELECT [a0].[SID], [a0].[FK_AnswerGrpBatch_SID], [a0].[FK_RecordState_SID], [t0].[SID] AS [SID0], [t0].[FK_AnswerGrp_SID], [t0].[FK_EnqPropertyForm_SID], [t0].[FK_PossResult_SID], [t0].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t0].[value], [t0].[SID0] AS [SID00], [t0].[FK_Deviation_SID], [t0].[FK_EnqPropResult_SID], [t0].[SID00] AS [SID000], [t0].[aDescription], [t0].[aName]
        FROM [AnswerGrp] AS [a0]
        LEFT JOIN (
            SELECT [e1].[SID], [e1].[FK_AnswerGrp_SID], [e1].[FK_EnqPropertyForm_SID], [e1].[FK_PossResult_SID], [e1].[FK_RecordState_SID], [e1].[value], [t].[SID] AS [SID0], [t].[FK_Deviation_SID], [t].[FK_EnqPropResult_SID], [t].[SID0] AS [SID00], [t].[aDescription], [t].[aName]
            FROM [EnqPropResult] AS [e1]
            LEFT JOIN (
                SELECT [e2].[SID], [e2].[FK_Deviation_SID], [e2].[FK_EnqPropResult_SID], [d].[SID] AS [SID0], [d].[aDescription], [d].[aName]
                FROM [EnqPropResultDev] AS [e2]
                INNER JOIN [Deviation] AS [d] ON [e2].[FK_Deviation_SID] = [d].[SID]
            ) AS [t] ON [e1].[SID] = [t].[FK_EnqPropResult_SID]
        ) AS [t0] ON [a0].[SID] = [t0].[FK_AnswerGrp_SID]
    ) AS [t1] ON [a].[SID] = [t1].[FK_AnswerGrpBatch_SID]
    WHERE [e0].[FK_RecordState_SID] = 0
) AS [t2] ON [e].[SID] = [t2].[FK_Enquiry_SID]
WHERE [e].[SID] = 1790797

但它必须是以下两个选项之一：

使用 IS NOT NULL 语句，但我无法弄清楚如何制作这个语句，因为它在不同的类中很深。

SELECT [e].[SID], [e].[FK_CRMPartner_SID], [e].[FK_Certificate_SID], [e].[createDate], [e].[displayDate], [e].[extID], [e].[finishDate], [e].[fixedGenId], [e].[aName], [t2].[SID], [t2].[FK_Enquiry_SID], [t2].[aName], [t2].[FK_RecordState_SID], [t2].[remark], [t2].[validFrom], [t2].[validTo], [t2].[SID0], [t2].[FK_EnqPartJob_SID], [t2].[FK_RecordState_SID0], [t2].[SID1], [t2].[FK_AnswerGrpBatch_SID], [t2].[FK_RecordState_SID1], [t2].[SID00], [t2].[FK_AnswerGrp_SID], [t2].[FK_EnqPropertyForm_SID], [t2].[FK_PossResult_SID], [t2].[FK_RecordState_SID00], [t2].[value], [t2].[SID000], [t2].[FK_Deviation_SID], [t2].[FK_EnqPropResult_SID], [t2].[SID0000], [t2].[aDescription], [t2].[aName0]
FROM [Enquiry] AS [e]
LEFT JOIN (
    SELECT [e0].[SID], [e0].[FK_Enquiry_SID], [e0].[aName], [e0].[FK_RecordState_SID], [e0].[remark], [e0].[validFrom], [e0].[validTo], [a].[SID] AS [SID0], [a].[FK_EnqPartJob_SID], [a].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t1].[SID] AS [SID1], [t1].[FK_AnswerGrpBatch_SID], [t1].[FK_RecordState_SID] AS [FK_RecordState_SID1], [t1].[SID0] AS [SID00], [t1].[FK_AnswerGrp_SID], [t1].[FK_EnqPropertyForm_SID], [t1].[FK_PossResult_SID], [t1].[FK_RecordState_SID0] AS [FK_RecordState_SID00], [t1].[value], [t1].[SID00] AS [SID000], [t1].[FK_Deviation_SID], [t1].[FK_EnqPropResult_SID], [t1].[SID000] AS [SID0000], [t1].[aDescription], [t1].[aName] AS [aName0]
    FROM [EnqPartJob] AS [e0]
    LEFT JOIN [AnswerGrpBatch] AS [a] ON [e0].[SID] = [a].[FK_EnqPartJob_SID]
    LEFT JOIN (
        SELECT [a0].[SID], [a0].[FK_AnswerGrpBatch_SID], [a0].[FK_RecordState_SID], [t0].[SID] AS [SID0], [t0].[FK_AnswerGrp_SID], [t0].[FK_EnqPropertyForm_SID], [t0].[FK_PossResult_SID], [t0].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t0].[value], [t0].[SID0] AS [SID00], [t0].[FK_Deviation_SID], [t0].[FK_EnqPropResult_SID], [t0].[SID00] AS [SID000], [t0].[aDescription], [t0].[aName]
        FROM [AnswerGrp] AS [a0]
        LEFT JOIN (
            SELECT [e1].[SID], [e1].[FK_AnswerGrp_SID], [e1].[FK_EnqPropertyForm_SID], [e1].[FK_PossResult_SID], [e1].[FK_RecordState_SID], [e1].[value], [t].[SID] AS [SID0], [t].[FK_Deviation_SID], [t].[FK_EnqPropResult_SID], [t].[SID0] AS [SID00], [t].[aDescription], [t].[aName]
            FROM [EnqPropResult] AS [e1]
            LEFT JOIN (
                SELECT [e2].[SID], [e2].[FK_Deviation_SID], [e2].[FK_EnqPropResult_SID], [d].[SID] AS [SID0], [d].[aDescription], [d].[aName]
                FROM [EnqPropResultDev] AS [e2]
                INNER JOIN [Deviation] AS [d] ON [e2].[FK_Deviation_SID] = [d].[SID]
            ) AS [t] ON [e1].[SID] = [t].[FK_EnqPropResult_SID]
        ) AS [t0] ON [a0].[SID] = [t0].[FK_AnswerGrp_SID]
    ) AS [t1] ON [a].[SID] = [t1].[FK_AnswerGrpBatch_SID]
    WHERE [e0].[FK_RecordState_SID] = 0
) AS [t2] ON [e].[SID] = [t2].[FK_Enquiry_SID]
WHERE [e].[SID] = 1790797 AND [t2].[SID000] IS NOT NULL

强制 INNER JOINS：

SELECT [e].[SID], [e].[FK_CRMPartner_SID], [e].[FK_Certificate_SID], [e].[createDate], [e].[displayDate], [e].[extID], [e].[finishDate], [e].[fixedGenId], [e].[aName], [t2].[SID], [t2].[FK_Enquiry_SID], [t2].[aName], [t2].[FK_RecordState_SID], [t2].[remark], [t2].[validFrom], [t2].[validTo], [t2].[SID0], [t2].[FK_EnqPartJob_SID], [t2].[FK_RecordState_SID0], [t2].[SID1], [t2].[FK_AnswerGrpBatch_SID], [t2].[FK_RecordState_SID1], [t2].[SID00], [t2].[FK_AnswerGrp_SID], [t2].[FK_EnqPropertyForm_SID], [t2].[FK_PossResult_SID], [t2].[FK_RecordState_SID00], [t2].[value], [t2].[SID000], [t2].[FK_Deviation_SID], [t2].[FK_EnqPropResult_SID], [t2].[SID0000], [t2].[aDescription], [t2].[aName0]
FROM [Enquiry] AS [e]
LEFT JOIN (
    SELECT [e0].[SID], [e0].[FK_Enquiry_SID], [e0].[aName], [e0].[FK_RecordState_SID], [e0].[remark], [e0].[validFrom], [e0].[validTo], [a].[SID] AS [SID0], [a].[FK_EnqPartJob_SID], [a].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t1].[SID] AS [SID1], [t1].[FK_AnswerGrpBatch_SID], [t1].[FK_RecordState_SID] AS [FK_RecordState_SID1], [t1].[SID0] AS [SID00], [t1].[FK_AnswerGrp_SID], [t1].[FK_EnqPropertyForm_SID], [t1].[FK_PossResult_SID], [t1].[FK_RecordState_SID0] AS [FK_RecordState_SID00], [t1].[value], [t1].[SID00] AS [SID000], [t1].[FK_Deviation_SID], [t1].[FK_EnqPropResult_SID], [t1].[SID000] AS [SID0000], [t1].[aDescription], [t1].[aName] AS [aName0]
    FROM [EnqPartJob] AS [e0]
    LEFT JOIN [AnswerGrpBatch] AS [a] ON [e0].[SID] = [a].[FK_EnqPartJob_SID]
    LEFT JOIN (
        SELECT [a0].[SID], [a0].[FK_AnswerGrpBatch_SID], [a0].[FK_RecordState_SID], [t0].[SID] AS [SID0], [t0].[FK_AnswerGrp_SID], [t0].[FK_EnqPropertyForm_SID], [t0].[FK_PossResult_SID], [t0].[FK_RecordState_SID] AS [FK_RecordState_SID0], [t0].[value], [t0].[SID0] AS [SID00], [t0].[FK_Deviation_SID], [t0].[FK_EnqPropResult_SID], [t0].[SID00] AS [SID000], [t0].[aDescription], [t0].[aName]
        FROM [AnswerGrp] AS [a0]
        INNER JOIN (
            SELECT [e1].[SID], [e1].[FK_AnswerGrp_SID], [e1].[FK_EnqPropertyForm_SID], [e1].[FK_PossResult_SID], [e1].[FK_RecordState_SID], [e1].[value], [t].[SID] AS [SID0], [t].[FK_Deviation_SID], [t].[FK_EnqPropResult_SID], [t].[SID0] AS [SID00], [t].[aDescription], [t].[aName]
            FROM [EnqPropResult] AS [e1]
            INNER JOIN (
                SELECT [e2].[SID], [e2].[FK_Deviation_SID], [e2].[FK_EnqPropResult_SID], [d].[SID] AS [SID0], [d].[aDescription], [d].[aName]
                FROM [EnqPropResultDev] AS [e2]
                INNER JOIN [Deviation] AS [d] ON [e2].[FK_Deviation_SID] = [d].[SID]
            ) AS [t] ON [e1].[SID] = [t].[FK_EnqPropResult_SID]
        ) AS [t0] ON [a0].[SID] = [t0].[FK_AnswerGrp_SID]
    ) AS [t1] ON [a].[SID] = [t1].[FK_AnswerGrpBatch_SID]
    WHERE [e0].[FK_RecordState_SID] = 0
) AS [t2] ON [e].[SID] = [t2].[FK_Enquiry_SID]
WHERE [e].[SID] = 1790797

问题是它将对除最后一个之外的每个 Include 和 ThenInclude 使用左连接。 但这也会检索我不需要的信息。 所以我尝试进行 LINQ 查询。

选项 2 LINQ

LINQ 查询总是使用 INNER JOINS，所以我完全可以从数据库中得到我想要的。 唯一的问题是我不知道如何在查询 class 中查询 map，其中 INNER JOINS 是查询 class 中的列表。 就像选项 1 一样。

     var query = from enquiry in _context.Set<Enquiry>()
                 join enqPartJob in _context.Set<EnqPartJob>()
                     on enquiry.Id equals enqPartJob.EnquiryId
                 join answerGrpBatch in _context.Set<AnswerGrpBatch>()
                     on enqPartJob.Id equals answerGrpBatch.EnqPartJobId
                 join answerGrp in _context.Set<AnswerGrp>()
                     on answerGrpBatch.Id equals answerGrp.AnswerGrpBatchId
                 join enqPropResult in _context.Set<EnqPropResult>()
                     on answerGrp.Id equals enqPropResult.AnswerGrpId
                 join enqPropResultDev in _context.Set<EnqPropResultDev>()
                     on enqPropResult.Id equals enqPropResultDev.EnqPropResultId
                 join deviation in _context.Set<Deviation>()
                     on enqPropResultDev.DeviationId equals deviation.Id
                 where enquiry.Id == id
                 select new { enquiry, enqPropResultDev };

是的，我知道 EFCore 使用 LEFT JOINS 是有原因的，但这不是我的数据库，所以我必须适应它。

Answer 1

感谢 Ivan Stoev，他评论了这个建议。

从 Deviation 开始，一直到 Inquiry 为我解决了问题。 查询现在看起来像这样（您可以看到它包含 INNER JOINS）。

SELECT [t].[SID], [t].[aDescription], [t].[aName], [t0].[SID], [t0].[FK_Deviation_SID], [t0].[FK_EnqPropResult_SID], [t0].[SID0], [t0].[FK_AnswerGrp_SID], [t0].[FK_EnqPropertyForm_SID], [t0].[FK_PossResult_SID], [t0].[FK_RecordState_SID], [t0].[value], [t0].[SID1], [t0].[FK_AnswerGrpBatch_SID], [t0].[FK_RecordState_SID0], [t0].[SID2], [t0].[FK_EnqPartJob_SID], [t0].[FK_RecordState_SID1], [t0].[SID3], [t0].[FK_Enquiry_SID], [t0].[aName], [t0].[FK_RecordState_SID2], [t0].[remark], [t0].[validFrom], [t0].[validTo], [t0].[SID4], [t0].[FK_CRMPartner_SID], [t0].[FK_Certificate_SID], [t0].[createDate], [t0].[displayDate], [t0].[extID], [t0].[finishDate], [t0].[fixedGenId], [t0].[aName0]
FROM (
    SELECT TOP(1) [d].[SID], [d].[aDescription], [d].[aName]
    FROM [Deviation] AS [d]
    WHERE [d].[SID] = 5038
) AS [t]
LEFT JOIN (
    SELECT [e].[SID], [e].[FK_Deviation_SID], [e].[FK_EnqPropResult_SID], [e0].[SID] AS [SID0], [e0].[FK_AnswerGrp_SID], [e0].[FK_EnqPropertyForm_SID], [e0].[FK_PossResult_SID], [e0].[FK_RecordState_SID], [e0].[value], [a].[SID] AS [SID1], [a].[FK_AnswerGrpBatch_SID], [a].[FK_RecordState_SID] AS [FK_RecordState_SID0], [a0].[SID] AS [SID2], [a0].[FK_EnqPartJob_SID], [a0].[FK_RecordState_SID] AS [FK_RecordState_SID1], [e1].[SID] AS [SID3], [e1].[FK_Enquiry_SID], [e1].[aName], [e1].[FK_RecordState_SID] AS [FK_RecordState_SID2], [e1].[remark], [e1].[validFrom], [e1].[validTo], [e2].[SID] AS [SID4], [e2].[FK_CRMPartner_SID], [e2].[FK_Certificate_SID], [e2].[createDate], [e2].[displayDate], [e2].[extID], [e2].[finishDate], [e2].[fixedGenId], [e2].[aName] AS [aName0]
    FROM [EnqPropResultDev] AS [e]
    INNER JOIN [EnqPropResult] AS [e0] ON [e].[FK_EnqPropResult_SID] = [e0].[SID]
    INNER JOIN [AnswerGrp] AS [a] ON [e0].[FK_AnswerGrp_SID] = [a].[SID]
    INNER JOIN [AnswerGrpBatch] AS [a0] ON [a].[FK_AnswerGrpBatch_SID] = [a0].[SID]
    INNER JOIN [EnqPartJob] AS [e1] ON [a0].[FK_EnqPartJob_SID] = [e1].[SID]
    INNER JOIN [Enquiry] AS [e2] ON [e1].[FK_Enquiry_SID] = [e2].[SID]
    WHERE [e0].[FK_RecordState_SID] = 0
) AS [t0] ON [t].[SID] = [t0].[FK_Deviation_SID]
ORDER BY [t].[SID], [t0].[SID], [t0].[SID0], [t0].[SID1], [t0].[SID2], [t0].[SID3], [t0].[SID4]