Question

我尝试在sql server 2008中创建数据库，并得到了这个错误：

Msg 1785，Level 16，State 0，Line 34

在表'Viewers'上引入FOREIGN KEY约束'Viewers_FK1'可能会导致循环或多个级联路径。指定ON   DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN KEY   限制。       Msg 1750，Level 16，State 0，Line 34       无法创建约束。查看以前的错误。

这是我的SQL查询：

CREATE DATABASE [ShemenHD];


GO 
USE [DBNAME1]
GO
CREATE TABLE Users( 
UserName VARCHAR(50) PRIMARY KEY, 
FullName VARCHAR(50) NOT NULL,
PhoneNum1 VARCHAR(20) ,
PhoneNum2 VARCHAR(20)
);  


CREATE TABLE Category( 
CategoryNum VARCHAR(15) PRIMARY KEY, 
CategoryName VARCHAR(30) NOT NULL
); 


CREATE TABLE Request( 
RequestNum VARCHAR(30) PRIMARY KEY,
RequestCreator VARCHAR(50) NOT NULL,
RequestCategory VARCHAR(15),
RequestSubject VARCHAR(250) NOT NULL,
RequestContent VARCHAR(2000) ,
RequestOpenDate datetime NOT NULL,
RequestCloseDate datetime  ,
RequestSLA datetime ,
RequestStatus VARCHAR(50) , 
RequestPriority VARCHAR(50) , 
IsProject BIT NOT NULL, 
RequestFile VARCHAR(500) ,


constraint Request_FK foreign key (RequestCreator) references  Users (UserName) ON DELETE NO ACTION ON UPDATE CASCADE,
constraint Request1_FK foreign key (RequestCategory) references  Category (CategoryNum) ON DELETE NO ACTION ON UPDATE CASCADE
); 

CREATE TABLE Viewers(
 UserName VARCHAR(50) ,
 RequestNum VARCHAR(30) 

 constraint Viewers_PK PRIMARY KEY (UserName, RequestNum),
 constraint Viewers_FK foreign key (UserName) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE,
 constraint Viewers_FK1 foreign key (RequestNum) references  Request(RequestNum)  ON DELETE NO ACTION ON UPDATE CASCADE
 );

 CREATE TABLE AdminNotes (
 NoteNumber VARCHAR(10) ,
 RequestNum VARCHAR(30) ,
 NoteCreator VARCHAR(50),
 NoteContent VARCHAR(2000) NOT NULL,

 constraint AdminNotes_PK PRIMARY KEY (NoteNumber, RequestNum), 
 constraint AdminNotes_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE CASCADE ,
 constraint AdminNotes_FK1 foreign key (NoteCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE 

 );


 CREATE TABLE RequestMessage (
 MessageNumber VARCHAR(10) ,
 RequestNum VARCHAR(30) ,
 MessageCreator VARCHAR(50),
 MessageContent VARCHAR(2000) NOT NULL,

 constraint RequestMessage_PK PRIMARY KEY (MessageNumber, RequestNum), 
 constraint RequestMessage_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE CASCADE  ,
 constraint RequestMessage_FK1 foreign key (MessageCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE 

 );

有什么问题？我想只在更新时级联，这会循环它的原因吗？我该如何解决呢？

谢谢!!

Answer 1

你好这里是带注释的固定代码：如上所述，您不能在多个表中使用相同的列作为外键并进行级联，您只能级联一次。

CREATE DATABASE [DBNAME1];


GO 
USE [DBNAME1]
GO
CREATE TABLE Users( 
UserName VARCHAR(50) PRIMARY KEY, 
FullName VARCHAR(50) NOT NULL,
PhoneNum1 VARCHAR(20) ,
PhoneNum2 VARCHAR(20)
);  


CREATE TABLE Category( 
CategoryNum VARCHAR(15) PRIMARY KEY, 
CategoryName VARCHAR(30) NOT NULL
); 


CREATE TABLE Request( 
RequestNum VARCHAR(30) PRIMARY KEY,
RequestCreator VARCHAR(50) NOT NULL,
RequestCategory VARCHAR(15),
RequestSubject VARCHAR(250) NOT NULL,
RequestContent VARCHAR(2000) ,
RequestOpenDate datetime NOT NULL,
RequestCloseDate datetime  ,
RequestSLA datetime ,
RequestStatus VARCHAR(50) , 
RequestPriority VARCHAR(50) , 
IsProject BIT NOT NULL, 
RequestFile VARCHAR(500) ,


constraint Request_FK foreign key (RequestCreator) references  Users (UserName) ON DELETE NO ACTION ON UPDATE CASCADE,
constraint Request1_FK foreign key (RequestCategory) references  Category (CategoryNum) ON DELETE NO ACTION ON UPDATE CASCADE
); 

CREATE TABLE Viewers(
 UserName VARCHAR(50) ,
 RequestNum VARCHAR(30) 

 constraint Viewers_PK PRIMARY KEY (UserName, RequestNum),
 --constraint Viewers_FK foreign key (UserName) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE, -- This cause error
 constraint Viewers_FK foreign key (UserName) references  Users(UserName) ON DELETE NO ACTION ON UPDATE NO ACTION, 
 constraint Viewers_FK1 foreign key (RequestNum) references  Request(RequestNum)  ON DELETE NO ACTION ON UPDATE CASCADE
 );

 CREATE TABLE AdminNotes (
 NoteNumber VARCHAR(10) ,
 RequestNum VARCHAR(30) ,
 NoteCreator VARCHAR(50),
 NoteContent VARCHAR(2000) NOT NULL,

 constraint AdminNotes_PK PRIMARY KEY (NoteNumber, RequestNum), 
 --constraint AdminNotes_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE CASCADE , --This cause error
 --constraint AdminNotes_FK1 foreign key (NoteCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE --This cause error
 constraint AdminNotes_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE NO ACTION , 
 constraint AdminNotes_FK1 foreign key (NoteCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE NO ACTION 

 );


 CREATE TABLE RequestMessage (
 MessageNumber VARCHAR(10) ,
 RequestNum VARCHAR(30) ,
 MessageCreator VARCHAR(50),
 MessageContent VARCHAR(2000) NOT NULL,

 constraint RequestMessage_PK PRIMARY KEY (MessageNumber, RequestNum), 
 --constraint RequestMessage_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE CASCADE  , --This cause error
 --constraint RequestMessage_FK1 foreign key (MessageCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE CASCADE --This cause error
 constraint RequestMessage_FK foreign key (RequestNum) references  Request(RequestNum) ON DELETE NO ACTION ON UPDATE NO ACTION  , 
 constraint RequestMessage_FK1 foreign key (MessageCreator) references  Users(UserName) ON DELETE NO ACTION ON UPDATE NO ACTION 

 );

在SQL SERVER中创建数据库时出错（循环或多个级联路径）

1 个答案: