SQL 错误："There are no primary or candidate keys in the referenced table..."

Question

我正在使用SQL Server 2008。我在尝试创建表"Dossier_Financement"时收到错误：

create table Dossier_Financement 
(
    ID_Reunion integer foreign key references Reunion(ID_Reunion),
    ID_Dossier integer foreign key references Dossier(ID_Dossier),
    Decision varchar(20),
    Motif text,
    Montant_Retenu decimal(6,2),/* montant accorder */
    Duree_Retenu smallint,/*nb jours accorder */
    Nom_Giac varchar(50) foreign key references GIAC(Nom_Giac),
    primary key(ID_Dossier,Nom_Giac,ID_Reunion)
)
GO

这是两个表：

create table Reunion 
(
    ID_Reunion integer ,
    Date_Reunion datetime,
    ID_Membre integer,/*jquery*/
    Type_Reunion varchar(20),
    Nom_Giac varchar(50),
    foreign key(ID_Membre,Nom_Giac) references Membre(ID_Membre,Nom_Giac),
    primary key(ID_Reunion,Nom_Giac)
)
GO

create table Dossier_Financement 
(
    ID_Reunion integer foreign key references Reunion(ID_Reunion),
    ID_Dossier integer foreign key references Dossier(ID_Dossier),
    Decision varchar(20),
    Motif text,
    Montant_Retenu decimal(6,2),/* montant accorder */
    Duree_Retenu smallint,/*nb jours accorder */
    Nom_Giac varchar(50) foreign key references GIAC(Nom_Giac),
    primary key(ID_Dossier,Nom_Giac,ID_Reunion)
)
GO

"团聚"正常执行没有任何问题，但是在尝试创建第二个表时出现此错误：

Msg 1776, Level 16, State 0, Line 1
There are no primary or candidate keys in the referenced table 'Reunion' that match the referencing column list in the foreign key 'FK__Dossier_F__ID_Re__5629CD9C'.
Msg 1750, Level 16, State 0, Line 1
Could not create constraint. See previous errors.

Answer 1

根据实际的模型需求/要求，一种解决方案是引用 Key，这需要所有部件（请注意，Nom_Giac 已添加到 FK 定义中）：

create table Dossier_Financement 
(
    ...
    foreign key(ID_Reunion,Nom_Giac) references Reunion(ID_Reunion,Nom_Giac),
)

---

根据 Mark M 的答案，另一种解决方案是将ID_Reunion列设为键（请注意，Nom_Giac已从 PK 定义中删除）：

create table Reunion 
(
    ...
    primary key(ID_Reunion)
)

这将使ID_Reunion成为键（实际上是主键），然后可以使用foreign key references Reunion(ID_Reunion)引用该键。

祝您编码愉快！

Answer 2

只能使用所引用表的完整主键创建外键。 第二个表尝试仅使用团聚表主键的一半来创建外键。

Answer 3

在要在其上创建索引的列上创建唯一索引：

CREATE UNIQUE NONCLUSTERED INDEX [UX_Index] ON dbo.[Table]([Column1],[Column2])