尝试在sql中创建外键时是否一直出错？

创建桌子室( RoomID nvarchar（8）主键， 容量数字（3）

)

创建表格房间类型( RoomType nvarchar（2）主键， 说明nvarchar（20）， nvarchar责任（20） )

更衣室

添加约束fk_类型外键（类型）引用RoomType（类型）

主要错误0x80040E11，次要错误0

更衣室 添加约束fk_类型外键（类型）引用RoomType（类型） 无效的列ID。[类型]

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可以创建组合RoomID和EquipmentType的表RoomEquipment，如下所示：

create table RoomEquipment (
  RoomID int,
  EquipmentType nvarchar(1),
  primary key (roomid, equipmenttype),
  constraint fk_roomequipment_equipment_type 
             foreign key (equipmenttype) 
             references equipment(equipmenttype),
  constraint fk_roomequipment_equipment_roomid
             foreign key (roomid) 
             references room(roomid)
);

-- I prefer using char datatype for predictable number of characters in a field
CREATE TABLE RoomType (
Roomtype nvarchar(2) NOT NULL,
Description nvarchar(20),
Responsibility nvarchar(20),
primary key (Roomtype)
);

-- You could use char(1) instead of nvarchar(1) for type; I'd prefer using int instead
create table Equipment (
Equipmenttype nvarchar(1) NOT NULL,
Description nvarchar(10)
);

-- Added a unique key to assist with good foreign key relationship
alter table Equipment add constraint uk_equipment_equipmenttype unique (equipmenttype);

-- Just use an int or char if roomID length is predictable
Create table Room (
RoomID nvarchar(8),
Capacity numeric(3),
Roomtype(fk,nvarchar(2)
);

alter table room add constraint uk_room_id unique (roomid);

其他表可能如下所示：

create table RoomEquipment (
  RoomID int,
  EquipmentType nvarchar(1),
  primary key (roomid, equipmenttype),
  constraint fk_roomequipment_equipment_type 
             foreign key (equipmenttype) 
             references equipment(equipmenttype),
  constraint fk_roomequipment_equipment_roomid
             foreign key (roomid) 
             references room(roomid)
);

-- I prefer using char datatype for predictable number of characters in a field
CREATE TABLE RoomType (
Roomtype nvarchar(2) NOT NULL,
Description nvarchar(20),
Responsibility nvarchar(20),
primary key (Roomtype)
);

-- You could use char(1) instead of nvarchar(1) for type; I'd prefer using int instead
create table Equipment (
Equipmenttype nvarchar(1) NOT NULL,
Description nvarchar(10)
);

-- Added a unique key to assist with good foreign key relationship
alter table Equipment add constraint uk_equipment_equipmenttype unique (equipmenttype);

-- Just use an int or char if roomID length is predictable
Create table Room (
RoomID nvarchar(8),
Capacity numeric(3),
Roomtype(fk,nvarchar(2)
);

alter table room add constraint uk_room_id unique (roomid);

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示例如下：

您想为您试图创建的表命名什么？您希望该表中包含哪些字段？哪些表和字段应该参与外键关系？我希望我要创建的表中的RoomID和Equipmenttype将房间与设备关联，这样新表将被称为RoomEquipment@Zedfoxus好的，房间设备在桌子上。它将有RoomID和EquipmentType字段。RoomEquipment的设备类型字段将与设备的设备类型字段相关。RoomEquipment的RoomID字段是否与任何内容相关？是，RoomID字段与房间表相关@zedfoxusOmg我忘了为房间添加桌子。我已经添加了桌子房间。请检查我使用适当外键创建

RoomEquipment

表格的第一块代码。这对你有用吗？在我的作业中，它说我们不允许合并任何表格，但这确实有帮助。谢谢。很高兴这是有帮助的。更新后的SQLFiddle示例如下所示，以供将来参考：