使用EF从数据库查询是否正确?

本文关键字：是否 查询 EF 数据库 使用 | 更新日期: 2023-09-27 18:15:33

我可以问这是否是使用EF删除整个数据库表的正确方法吗?Department表连接Facility和departmentd，Facility表连接Facility Reservation和FacilityID，我需要删除Facility Reservation表中的所有记录。有人可以指导我，告诉我这是正确的吗?谢谢你！

    db.Database.ExecuteSqlCommand(
                    "DELETE FacilityReservation FROM Department INNER JOIN Facility ON Department.DepartmentID = Facility.DepartmentID " +
                        "INNER JOIN FacilityReservation ON Facility.FacilityID = FacilityReservation.FacilityID WHERE Department.DepartmentID =" + departmentID);

使用EF从数据库查询是否正确?

不，当然不是，您需要DELETE FROM ，并且当您执行连接时，您需要另一个"FROM

"。

你可能想要这个:

DELETE FROM FacilityReservation 
INNER JOIN Facility 
    ON Facility.FacilityID = FacilityReservation.FacilityID 
INNER JOIN Department 
    ON Department.DepartmentID = Facility.DepartmentID 
WHERE Department.DepartmentID = @departmentID;

从SQL语句中，看起来可以从Facility表中检索DepartmentID。因此，您的SQL语句可以相当简单，如:

DELETE a
FROM FacilityReservation a
INNER JOIN Facility b ON a.FacilityID = b.FacilityID
WHERE b.DepartmentID = @departmentID
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