Question

我有一个LINQ查询，它将根据是否满足一些条件来选择故障单。查询本身运行正常并且运行正常，但我担心随着可能的回报数量的增加，它会随着它的变化而显着变差。

有人可以建议改进或优化此查询以更快/更好地运行的方法吗？我是否对标准做法做了可怕的错误？

这是查询。我换了一些名字。我认为select语句中的select new也是一个问题。

var attentionObj = (from c in context.SupportTicketEntities
                    where
                    c.StatusID != 3 && 
                    ((c.IsAllocated == false)    // not allocated
                    || (c.FlaggedForAssist == true && c.AllocatedToEmployeeID == empId)     // is flagged for assist
                    || ((from d in c.SupportTicketDatas
                         where c.AllocatedToEmployeeID == empId
                         && c.FogBugzAttachments.Count == 0
                         orderby d.TimeStamp descending
                         select d.TimeStamp).FirstOrDefault() < warningDt)   // ticket not replied to
                    || ((from e in c.SupportTicketDatas
                         where c.AllocatedToEmployeeID == empId
                         orderby e.TimeStamp descending
                         select e).FirstOrDefault().RaisedByUser == true)   // customer has replied
                    || (c.IsEscalated == true))  // ticket escalated
                    select new
                    {
                        RefID = c.RefID,
                        TicketID = c.SupportTicketID,
                        ClientCompany = c.ClientData.Company,
                        IsAllocated = c.IsAllocated,
                        DateLogged = c.DateLogged,
                        IsFlagged = c.FlaggedForAssist,
                        NeedsReply = (from d in c.SupportTicketDatas
                                      orderby d.TimeStamp descending
                                      select d.TimeStamp).FirstOrDefault() < warningDt,
                        CustReply = (from e in c.SupportTicketDatas
                                     orderby e.TimeStamp descending
                                     select e).FirstOrDefault().RaisedByUser == true,
                        IsEscalated = c.IsEscalated
                    }).ToArray();

编辑：所以我已经创建了一个存储过程，尽管我并不是最好的SQL。这没关系吗？

@empId int,
@warningDt datetime
AS
SELECT * FROM SupportTickets
WHERE StatusID != 3
AND IsAllocated = 0
UNION
SELECT * FROM SupportTickets
WHERE StatusID != 3
AND FlaggedForAssist = 1
AND AllocatedToEmployeeID = @empId
UNION
SELECT * FROM SupportTickets
WHERE StatusID != 3
AND AllocatedToEmployeeID = @empId
AND NOT EXISTS (SELECT FogBugzLinkID FROM FogBugzAttachment)
AND (SELECT MAX(TimeStamp) 
 FROM SupportTicketData
 WHERE SupportTickets.SupportTicketID = SupportTicketData.SupportTicketID) < @warningDt
UNION
SELECT SupportTickets.* FROM SupportTickets
JOIN SupportTicketData ON SupportTickets.SupportTicketID = SupportTicketData.SupportTicketID
WHERE SupportTickets.StatusID != 3
AND SupportTickets.AllocatedToEmployeeID = @empId
AND SupportTicketData.TimeStamp = (SELECT MAX(TimeStamp) FROM SupportTicketData
                   WHERE SupportTickets.SupportTicketID = SupportTicketData.SupportTicketID)
AND SupportTicketData.RaisedByUser = 1
UNION
SELECT * FROM SupportTickets
WHERE StatusID != 3
AND SupportTickets.IsEscalated = 1

Answer 1

所以看起来像使用我的初始语句中的存储过程比使用可怕的LINQ OR语句更有效。

我将此标记为答案，以便关闭。看看我对SPROC的原始问题。

Linq到实体查询优化

1 个答案: