Как мне создать T-SQL Cross-Apply с Entity Framework Core? - PullRequest
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Как мне создать T-SQL Cross-Apply с Entity Framework Core?

0 голосов
/ 19 сентября 2019

Я хочу создать запрос с помощью Entity Framework Core, который имеет несколько INNER JOIN и одно CROSS APPLY.

Я могу прекрасно создать ВНУТРЕННИЕ СОЕДИНЕНИЯ, но, похоже, не работает CROSS APPLY.

  • Неужели в поиске по шине Google ничего толкового не получилось
  • Пробовал разные вещи с помощью операторов linq Entity Framework, но пока безрезультатно.

Это EF-запрос, который я получил до сих пор: 

comCommunicationContext
    .Communication
    .AsNoTracking()
    .Where(c => c.Label.InternalName == labelName && 
                c.Businesstransaction.DocumentType.DocumentTypeName == documentType && 
                c.Businesstransaction.SourceSystem.SourceSystemName == sourceSystem)
    .Join(comCommunicationContext.CommunicationOutputChannel,  communicationEntity => communicationEntity.CommunicationId, communicationOutputChannelEntity => communicationOutputChannelEntity.CommunicationId, (communicationEntity, communicationOutputChannelEntity) => new {Communication = communicationEntity, CommunicationOutputChannel = communicationOutputChannelEntity})
    .Where(y => y.CommunicationOutputChannel.OutputChannel == outputChannel)
    .Join(comCommunicationContext.CommunicationStatusOutputChannel.
Where(x => x.Status=="to process"), communicationOutputChannelEntity => communicationOutputChannelEntity.CommunicationOutputChannel.CommunicationOutputChannelId, communicationStatusOutputChannelEntity => communicationStatusOutputChannelEntity.CommunicationOutputChannelId, (outer, inner) => new Communication() { CommunicationDataEnriched = outer.Communication.CommunicationDataEnriched })

, который производит следующий запрос T-SQL: 

SELECT [c].[CommunicationDataEnriched]
FROM [Communications] AS [c]
INNER JOIN [Businesstransactions] AS [c.Businesstransaction] ON [c].[BusinessTransactionId] = [c.Businesstransaction].[BusinessTransactionId]
INNER JOIN [DocumentTypes] AS [c.Businesstransaction.DocumentType] ON [c.Businesstransaction].[DocumentTypeId] = [c.Businesstransaction.DocumentType].[DocumentTypeId]
INNER JOIN [SourceSystems] AS [c.Businesstransaction.SourceSystem] ON [c.Businesstransaction].[SourceSystemId] = [c.Businesstransaction.SourceSystem].[SourceSystemId]
INNER JOIN [Labels] AS [c.Label] ON [c].[LabelId] = [c.Label].[LabelId]
INNER JOIN [CommunicationOutputChannels] AS [CommunicationOutputChannels] ON [c].[CommunicationId] = [CommunicationOutputChannels].[CommunicationId]
INNER JOIN (
    SELECT [x].*
    FROM [CommunicationStatusOutputChannels] AS [x]
    WHERE [x].[Status] = 'to process'
) AS [t] ON [CommunicationOutputChannels].[CommunicationOutputChannelId] = [t].[CommunicationOutputChannelId]
WHERE ((([c.Label].[InternalName] = 'labelname') AND ([c.Businesstransaction.DocumentType].[DocumentTypeName] = 'documenttype')) AND ([c.Businesstransaction.SourceSystem].[SourceSystemName] = 'sourcessysem')) AND ([CommunicationOutputChannels].[OutputChannel] = 'email')

Что бы я хотелотправить в базу данных это: 

SELECT [c].[CommunicationDataEnriched]
FROM [Communications] AS [c]
INNER JOIN [Businesstransactions] AS [c.Businesstransaction] ON [c].[BusinessTransactionId] = [c.Businesstransaction].[BusinessTransactionId]
INNER JOIN [DocumentTypes] AS [c.Businesstransaction.DocumentType] ON [c.Businesstransaction].[DocumentTypeId] = [c.Businesstransaction.DocumentType].[DocumentTypeId]
INNER JOIN [SourceSystems] AS [c.Businesstransaction.SourceSystem] ON [c.Businesstransaction].[SourceSystemId] = [c.Businesstransaction.SourceSystem].[SourceSystemId]
INNER JOIN [Labels] AS [c.Label] ON [c].[LabelId] = [c.Label].[LabelId]
INNER JOIN [CommunicationOutputChannels] AS [CommunicationOutputChannels] ON [c].[CommunicationId] = [CommunicationOutputChannels].[CommunicationId]
CROSS APPLY (
    SELECT TOP 1 [x].*
    FROM [CommunicationStatusOutputChannels] AS [x]
    WHERE [x].[Status] = 'to process'
    AND [x].[CommunicationOutputChannelId] = [CommunicationOutputChannels].[CommunicationOutputChannelId]
    ORDER BY [x].createdOn DESC
) [t]
WHERE ((([c.Label].[InternalName] = 'labelname') AND ([c.Businesstransaction.DocumentType].[DocumentTypeName] = 'documenttype')) AND ([c.Businesstransaction.SourceSystem].[SourceSystemName] = 'sourcessysem')) AND ([CommunicationOutputChannels].[OutputChannel] = 'email')

Объект CommunicationOutputChannel имеет свойство навигации CommunicationStatusOutputChannels типа ICollection<CommunicationStatusOutputChannel> (существует отношение один-ко-многим между CommunicationOutputChannel и CommunicationStatusOutputChannels лица).

Таким образом, последние INNER JOIN между таблицами CommunicationOutputChannels и CommunicationStatusOutputChannels должны быть CROSS APPLY.

1 Ответ

0 голосов
/ 19 сентября 2019

Nevermind.Нашел решение, которое работает для меня. 

 var q = from c in comCommunicationContext.Communication.Where(c=>c.Label.InternalName==labelName && c.Businesstransaction.DocumentType.DocumentTypeName==documentType && c.Businesstransaction.SourceSystem.SourceSystemName==sourceSystem)
                    join coc in comCommunicationContext.CommunicationOutputChannel
                    on c.CommunicationId equals coc.CommunicationId
                    from csoc in comCommunicationContext.CommunicationStatusOutputChannel.Where(x=>x.CommunicationOutputChannelId==coc.CommunicationOutputChannelId).OrderByDescending(y=>y.CreatedOn).Take(1)
                    where csoc.Status == "to process"
                    select new Communication(){CommunicationDataEnriched = c.CommunicationDataEnriched}
                ;
...