LINQ to实体在DateTime.DayOfWeek上加入 [英] LINQ to Entities Join on DateTime.DayOfWeek

问题描述

想象两个表:Shifts，RANK_S_DAY. Shifts包含一个DateTime的ShiftDate列，而RANK_S_DAY包含一个DayOfWeek列.我需要加入(int)ShiftDate.DayOfWeek equals DayOfWeek.我知道为什么它不起作用，但是我不太确定如何更改它.例外是:

Imagine two tables: Shifts, RANK_S_DAY. Shifts contains a ShiftDate column which is DateTime and RANK_S_DAY has a DayOfWeek column. I need to join (int)ShiftDate.DayOfWeek equals DayOfWeek. I understand why it won't work, but I'm not quite sure how I can change it. The Exception is:

LINQ to Entities不支持指定的类型成员'DayOfWeek'.仅支持初始化程序，实体成员和实体导航属性.

The specified type member 'DayOfWeek' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

据我了解，LINQ无法将(int)ShiftDate.DayOfWeek转换为SQL可以理解的东西，有什么想法吗?

As I understand it, LINQ can't translate (int)ShiftDate.DayOfWeek to something SQL understands, Any ideas?

这是代码:

Shifts = from s in en.Shifts
join j in en.RANK_S_JOB on s.kronos_JobPositions.JobID equals j.JOBNO
join d in en.RANK_S_DAY on (int)s.ShiftDate.DayOFWeek equals d.DAY_OF_WEEK
orderby
 d.RANK,
 j.RANK ascending
select s;

推荐答案

在这个级别上我无能为力.因此，我要做的是创建一个存储过程，该过程将两个表连接在一起并将其导入到Entity中，创建了一个函数导入，该函数返回了一个Shifts实体.不确定这是否是最好的方法，但它是否有效并且是否干净.

It appears there isn't anything I can do at this level. So what I've done is created a stored proc that joins the two tables and imported it into the Entity, created a function import that returned a Shifts entity. Not sure if thats the best approach, but it works and is clean.

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