SQL内部联接的Linq等效语句和IN语句

Question

CREATE TABLE PersonTask
(
PersonId INT NOT NULL,
WeekId INT NOT NULL,
WeekDaysTaskId INT,
WeekEndTaskId INT
)
GO
CREATE TABLE Task
(
Id INT PRIMARY KEY,
[Description] VARCHAR(250) NOT NULL
)
GO
INSERT INTO Task(Id, [Description]) VALUES(1, 'Task-01')
INSERT INTO Task(Id, [Description]) VALUES(2, 'Task-02')
INSERT INTO Task(Id, [Description]) VALUES(3, 'Task-03')
GO
INSERT INTO PersonTask(PersonId, WeekId, WeekDaysTaskId, WeekEndTaskId) VALUES(1, 1, NULL, 1)
INSERT INTO PersonTask(PersonId, WeekId, WeekDaysTaskId, WeekEndTaskId) VALUES(1, 2, 2, NULL)
INSERT INTO PersonTask(PersonId, WeekId, WeekDaysTaskId, WeekEndTaskId) VALUES(1, 3, 3, 3)
GO

SELECT 
        PT.PersonId, 
        WeekId,
        'Not on Bench' as [Status]
    FROM PersonTask AS PT
    INNER JOIN Task AS T ON T.Id IN (PT.WeekDaysTaskId, PT.WeekEndTaskId)
    WHERE WeekId = 3/*Param-1*/ and PersonId = 1/*Param-2*/

我试图写一个等效于上述T-sql语句的linq查询，但是徒劳。 有人可以帮助C＃Linq查询来获取上面的T-SQL语句。

Answer 1

必须类似（假设您有personTaskQueryable和taskQueryable）：

from pt in personTaskQueryable
from t in taskQueryable
where (t.Id == pt.WeekDaysTaskId || t.Id == pt.WeekEndTaskId)
    && pt.WeekId == 3 && pt.PersonId == 1
select new { pt.PersonId, pt.WeekId, Status = "Not on Bench" }

我没有尝试，因为我是直接在答案文本框中编码的，但是Linq文档说您不能使用“ join”运算符执行此类操作，因为它仅支持equijoins。

解决方案是首先构建笛卡尔乘积并从那里限制结果集。