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EF写统计
EF的特性是,你from的第一个表为主表,接下来的所有表以左联或者内联或者交叉连接的方式去显示,不会出现右联,
在编写的时候,可以先确定个数据源,然后对这个数据源进行数据的统计,
例如SQL:
-- Region Parameters DECLARE @p0 VarChar(1000) = ‘ExamImage‘ DECLARE @p1 VarChar(1000) = ‘‘ DECLARE @p2 Float = 1024 DECLARE @p3 Float = 1024 -- EndRegion SELECT SUM(((CONVERT(Float,[t6].[value])) / @p2) / @p3) AS [FileSize], MAX([t6].[value2]) AS [UploadTime], [t6].[ResultDate] FROM ( SELECT [t3].[FileSize] AS [value], [t3].[UploadTime] AS [value2], [t0].[ResultDate], [t3].[TypeCode], [t0].[ServiceSectID], [t3].[DeleteFlag] FROM [a] AS [t0] LEFT OUTER JOIN [b] AS [t1] ON [t0].[VisitUID] = ([t1].[VisitUID]) LEFT OUTER JOIN [c] AS [t2] ON ([t0].[PatientID] = [t2].[PatientID]) AND ([t0].[PatientMasterID] = [t2].[PatientMasterID]) LEFT OUTER JOIN [d] AS [t3] ON (CONVERT(NVarChar(MAX),[t0].[ObservationUID])) = [t3].[BusinessID] LEFT OUTER JOIN [e] AS [t4] ON [t3].[FileUID] = [t4].[FileUID] LEFT OUTER JOIN [f] AS [t5] ON [t0].[OrganizationID] = [t5].[OrganizationID] ) AS [t6] WHERE ([t6].[TypeCode] = @p0) AND ([t6].[ServiceSectID] <> @p1) AND (NOT ([t6].[DeleteFlag] = 1)) GROUP BY [t6].[ResultDate]
翻译成linq可以进行如下写法:
from item in ( from o in a join v in bon o.VisitUID equals v.VisitUID into o_vJoin from o_v in o_vJoin.DefaultIfEmpty() join p in b on new { PatientID = o.PatientID, PatientMasterID = o.PatientMasterID } equals new { p.PatientID, p.PatientMasterID } into o_pJoin from o_v_p in o_pJoin.DefaultIfEmpty() join d in c on o.ObservationUID.ToString() equals d.BusinessID into o_dJoin from o_v_p_d in o_dJoin.DefaultIfEmpty() join dis in d on o_v_p_d.FileUID equals dis.FileUID into d_disJoin from o_v_p_d_dis in d_disJoin.DefaultIfEmpty() join om in e on o.OrganizationID equals om.OrganizationID into o_omJoin from o_v_p_d_dis_om in o_omJoin.DefaultIfEmpty() where o_v_p_d.TypeCode == "ExamImage" && o.ServiceSectID != "" && !o_v_p_d.DeleteFlag select new { FileSize = o_v_p_d.FileSize, UploadTime = o_v_p_d.UploadTime, ResultDate = o.ResultDate } ) group item by new { item.ResultDate} into res select new { FileSize = res.Sum(t => t.FileSize/1024d/1024d), UploadTime = res.Max(t => t.UploadTime), ResultDate = res.Select(t => t.ResultDate), }
这其中涉及到了多表连接,以及使用聚合函数对列进行统计的语法,希望对大家有帮助
EF写统计
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