Question

我对Linq和实体框架有点新意，我需要在我的数据访问层中编写linq查询。我想要生成的sql是：

Select  c.Configurationid, 
        ConfigurationDescription, 
        coalesce(d.enrolment,0) as Enrolment,
        coalesce(d.accepts,0) as Accepts, 
        coalesce(d.rejects,0) as Rejects, 
        coalesce(d.incomplete,0) as Incomplete      
from VVConfiguration c with (nolock) 
LEFT JOIN (
Select ConfigurationId,
        Sum(case when d.dialoguestatusid = 1 and d.processtypeid = 1 and e.CreateDate = dates.maxcreatedate then 1 else 0 end) as enrolment,
        sum(case when ec.verificationdecisionid in (2, 3, 5) and d.ProcessTypeID = 2 and e.CreateDate = dates.maxcreatedate then 1 else 0 end) as accepts,
        sum(case when ec.verificationdecisionid = 6 and d.ProcessTypeID = 2 and e.CreateDate = dates.maxcreatedate then 1 else 0 end) as rejects,
        sum(case when d.dialoguestatusid = 4 and (e.CreateDate = dates.maxcreatedate or e.CreateDate IS NULL) then 1 else 0 end) as Incomplete  
 from dbo.dialogue d with (nolock)
 LEFT JOIN exchange e with (nolock) on e.dialogueid = d.dialogueid
 LEFT JOIN exchangeclaimant ec on e.exchangeid = ec.ExchangeID
 left JOIN 
 (Select a.DialogueID,max(ex.CreateDate) as maxcreatedate from Dialogue a (nolock)
                    JOIN Exchange ex with (nolock) on a.dialogueId = ex.dialogueid                                          
                    group by (a.dialogueid)) dates on dates.maxcreatedate = e.createdate and dates.DialogueID = d.DialogueID

group by d.configurationid ) d  on d.configurationid = c.configurationid
Where c.OrganisationUnitId = '1234'
order by configurationdescription

通过阅读一些关于SO的文章和问题，我提出了这个问题，但查询提供了一些错误的数据，并且运行时间太长。

有人可以帮助我，我做错了什么？

(from c in this.context.VVConfiguration
join p in
    (
        from d in this.context.Dialogue
        join e in this.context.Exchange on d.DialogueID equals e.DialogueID into ex
        from exd in ex.DefaultIfEmpty()
        join ec in this.context.ExchangeClaimant on exd.ExchangeID equals ec.ExchangeID into exc
        from exec in exc.DefaultIfEmpty()
        join date in
            (
                from di in this.context.Dialogue
                join x in this.context.Exchange on di.DialogueID equals x.ExchangeID
                join xc in this.context.ExchangeClaimant on x.ExchangeID equals xc.ExchangeID
                group xc by new { di.DialogueID } into dates
                select new
                {
                    MaxDate = dates.Max(a => a.Exchange.CreateDate)
                }
            ) on exec.Exchange.CreateDate equals date.MaxDate into xc
        from xec in xc.DefaultIfEmpty()
        group exec by new { d.ConfigurationID } into g
        select new
        {
            ConfigurationID = g.Key.ConfigurationID,
            Enrolment = g.Sum(a => ((a.Exchange.Dialogue.DialogueStatusID == 1 && a.Exchange.Dialogue.ProcessTypeID == 1) ? 1 : 0)),
            Accepts = g.Sum(a => ((acceptsVerficationList.Contains(a.VerificationDecisionID) && a.Exchange.Dialogue.ProcessTypeID == 2) ? 1 : 0)),
            Rejects = g.Sum(a => ((a.VerificationDecisionID == 6 && a.Exchange.Dialogue.ProcessTypeID == 2) ? 1 : 0)),
            InComplete = g.Sum(a => (a.Exchange.Dialogue.DialogueStatusID == 4) ? 1 : 0)
        }
    ) on c.ConfigurationID equals p.ConfigurationID into details
from configuration in details.DefaultIfEmpty()
where c.OrganisationUnitID == new Guid(organizationId)
orderby c.ConfigurationDescription
select new ConfigurationDetails
 {
     ConfigurationID = c.ConfigurationID,
     ConfigurationDescription = c.ConfigurationDescription,
     Enrolment = configuration.Enrolment,
     Accepts = configuration.Accepts,
     Rejects = configuration.Rejects,                                            
     InComplete = configuration.InComplete
 }).ToList();

Answer 1

我不确定你的情况但是＆＃39;纠正＆＃39;解决方案是创建存储过程，并调用它而不是编写此linq语句。

这是一篇如何做的文章

http://www.entityframeworktutorial.net/EntityFramework4.3/execute-stored-procedure-using-dbcontext.aspx

包含sum和子查询的Linq查询无法正常工作

1 个答案: