C# SQL到LINQ处理左外部联接中的匹配

我正在尝试将下面的SQL转换为LINQ查询，我一直在使用左外联接中的匹配项筛选结果

SELECT @batchID , IQ1.ID, @environment , 'IRD', IQ1.ReportingDate, IQ1.Match
FROM    (
        SELECT  TD.*, RD.Match
        FROM    TransactionDetail TD
                INNER JOIN .dbo.Measure M ON M.InternalID = TD.MetricCode-- and TD.BatchID = 'e07f9855-b286-4406-9189-5cfb2a7914c8'
                LEFT OUTER JOIN (
                    SELECT tmp.ID, tmp.ReportingDate, 1 AS Match
                    FROM tmp
                ) AS RD ON RD.ID = M.Frequency AND RD.ReportingDate = TD.ReportingDate
        WHERE   RD.Match IS NULL AND
                TD.BatchID = @batchID AND
                NOT EXISTS (SELECT TransactionFailureReasonID FROM TransactionDetailFailureReasons R WHERE R.TransactionDetailID = TD.ID and R.TransactionFailureReasonID = 'NRD') AND
                NOT EXISTS (SELECT TransactionFailureReasonID FROM TransactionDetailFailureReasons R WHERE R.TransactionDetailID = TD.ID and R.TransactionFailureReasonID = 'RDP') AND
                NOT EXISTS (SELECT TransactionFailureReasonID FROM TransactionDetailFailureReasons R WHERE R.TransactionDetailID = TD.ID and R.TransactionFailureReasonID = 'RDF')
        ) AS IQ1

到目前为止，我取得了如下成就：

// Prepare data for left outer join
        var rd = (from tt in result
                  select new { ID = tt.Id, tt.ReportingDate });

        // inner join
        var td = TransactionDetail.Join(
            MesureTb,
            t => t.MetricCode,
            m => m.InternalId,
            (t, m) => new
            {
                t.Id,
                t.RowAction,
                t.BatchId,
                t.TrustCode,
                t.MetricCode,
                t.ReportingDate,
                t.Value,
                t.UpperBenchmark,
                t.LowerBenchmark,
                m.InternalId,
                Frequency = m.Frequency
            });

        // left outer join
        var failureTransactionDetail = (from p in td
                                        join q in rd on new { ReportingDate = (DateTime)p.ReportingDate, ID = p.Frequency } equals new { q.ReportingDate, q.ID }
                                        into LJ
                                        //select new { p.Id, p.BatchId, p.ReportingDate, RD = q.ReportingDate, q.ID, p.Frequency });
                                        from value in LJ.DefaultIfEmpty()
                                        //where p.BatchId == batchId
                                        select new {p.BatchId,  p.Id, Match = 1, p.ReportingDate } into DJ
                                        // LEFT OUTER JOIN
                                        where DJ.BatchId == batchId
                                        ////&& DJ.Match == 0
                                        && !(TransactionDetailFailureReasons.Any(m => m.TransactionDetailId == DJ.Id && m.TransactionFailureReasonId == "NRD"))
                                        && !(TransactionDetailFailureReasons.Any(m => m.TransactionDetailId == DJ.Id && m.TransactionFailureReasonId == "RDP"))
                                        && !(TransactionDetailFailureReasons.Any(m => m.TransactionDetailId == DJ.Id && m.TransactionFailureReasonId == "RDF"))
                                        select new { DJ.Id, DJ.ReportingDate, DJ.BatchId } );

我的问题是如何在Linq中的SQL中获得与1相似的结果

有人能给我引路吗？目前，SQL查询基于匹配值返回2个结果，结果为null，但LInq返回8个结果，因为它没有过滤左连接上的匹配

非常感谢您的帮助

---

提前谢谢。

我只是想帮你一下，因为这个问题有点不清楚。但是，只要将sql语句与linq查询进行比较，我就可以看出您可能正在尝试筛选以下位置：RD.Match为NULL？如果这个假设是正确的，那么linq查询就有问题了

鉴于以下对象：

public class TransactionDetail
{
    public TransactionDetail(int id, 
        int batchId, 
        int metricCode, 
        DateTime reportingDate)
    {
        Id = id;
        BatchId = batchId;
        MetricCode = metricCode;
        ReportingDate = reportingDate;
    }

    public int Id { get; }
    public int BatchId { get; }
    public int MetricCode { get; }
    public DateTime ReportingDate { get; }
}

public class Measure
{
    public Measure(int internalId, 
        int frequency)
    {
        InternalId = internalId;
        Frequency = frequency;
    }

    public int InternalId { get; }
    public int Frequency { get; }
}

public class Tmp
{
    public Tmp(int id, 
        DateTime reportingDate)
    {
        Id = id;
        ReportingDate = reportingDate;
    }

    public int Id { get; }
    public DateTime ReportingDate { get; }
}

示例代码：

    static void Main(string[] args)
    {
        var transactionDetails = new List<TransactionDetail>
        {
            new TransactionDetail(id: 1, batchId: 1, metricCode: 1, reportingDate: new DateTime(2019, 1, 1)),
            new TransactionDetail(id: 2, batchId: 1, metricCode: 2, reportingDate: new DateTime(2019, 1, 1))
        };

        var matches = new List<Measure>
        {
            new Measure(internalId: 1, frequency: 1),
            new Measure(internalId: 2, frequency: 3)
        };

        var temporaryList = new List<Tmp>
        {
            new Tmp(1, new DateTime(2019, 1, 1)),
        };

        var transDetails = transactionDetails.Join(
            matches,
            t => t.MetricCode,
            m => m.InternalId,
            (t, m) => new
            {
                t.Id,
                t.BatchId,
                t.MetricCode,
                t.ReportingDate,
                m.InternalId,
                m.Frequency
            })
            .ToList();

        var failureTransactionDetail = transDetails
            .GroupJoin(temporaryList,
                trandetail => new { trandetail.ReportingDate, Id = trandetail.Frequency },
                tmp => new { tmp.ReportingDate, tmp.Id },
                (trandetail, tmp) => new { trandetail, tmp })
            .SelectMany(t => t.tmp.DefaultIfEmpty(), (t, value) => new { t, value, Matches = 1 })
            .Where(arg => !arg.t.tmp.Any());

        Console.WriteLine(JsonConvert.SerializeObject(failureTransactionDetail, Formatting.Indented));

        Console.ReadLine();
    }

static void Main（字符串[]args）
{
var transactionDetails=新列表
{
新交易详情（id:1，batchId:1，metricCode:1，reportingDate:new DateTime（2019，1，1）），
新交易详情（id:2，批次id:1，度量代码：2，报告日期：新日期时间（2019，1，1））
};
var matches=新列表
{
新措施（内部ID:1，频率：1），
新措施（内部ID:2，频率：3）
};
var temporaryList=新列表
{
新Tmp（1，新日期时间（2019，1，1）），
};
var transDetails=transactionDetails.Join(
比赛，
t=>t.MetricCode，
m=>m.InternalId，
（t，m）=>新
{
t、 身份证，
t、 BatchId，
t、 公制代码，
t、 报告日期：，
m、 内在的，
m、 频率
})
.ToList（）；
var failureTransactionDetail=transDetails
.GroupJoin（临时列表，
trandetail=>new{trandetail.ReportingDate，Id=trandetail.Frequency}，
tmp=>new{tmp.ReportingDate，tmp.Id}，
（trandetail，tmp）=>新的{trandetail，tmp}）
.SelectMany（t=>t.tmp.DefaultIfEmpty（），（t，value）=>new{t，value，Matches=1}）
.Where（arg=>！arg.t.tmp.Any（））；
WriteLine（JsonConvert.SerializeObject（failureTransactionDetail，Formatting.Indented））；
Console.ReadLine（）；
}

检查输出，您将看到不需要

Match=1

.Where（arg=>！arg.t.tmp.Any（））

将等效于sql查询中的RD.Match为NULL

---

希望这能帮你找到正确的方向

在sql设置

1为Match

中，只输出所有行的数字1。你不应该设置Match=1而不是true吗？我确实尝试了1，但这不会过滤值，我假设我的Linq查询存在一些问题。非常感谢上面的内容，它确实帮助了很多。没问题@PUBG很高兴我能帮上忙。干杯