MySQL ALTER TABLE 添加约束
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ALTER TABLE add constraint
提问by ABLX
CREATE TABLE Properties
(
ID int AUTO_INCREMENT,
language int,
stonecolor int,
gamefield int,
UserID int,
PRIMARY KEY(ID),
FOREIGN KEY(language) REFERENCES Language(ID),
FOREIGN KEY(stonecolor) REFERENCES StoneColor(ID),
FOREIGN KEY(gamefield) REFERENCES GameField(ID)
) ENGINE = INNODB;
CREATE TABLE User
(
ID int AUTO_INCREMENT,
vorname varchar(30) NOT NULL,
name varchar(30) NOT NULL,
email varchar(40) NOT NULL,
password varchar(40) NOT NULL,
nickname varchar(15) NOT NULL,
score int,
isadmin int DEFAULT 0,
gamesPlayed int,
properties int NOT NULL,
PRIMARY KEY(ID),
UNIQUE (email),
UNIQUE (nickname)
) ENGINE = INNODB;
ALTER TABLE User
(
ADD CONSTRAINT userPropertie
FOREIGN KEY(properties)
REFERENCES Properties(ID)
)
The tables were created properly, but the ALTER TABLE doesn't work. cant figure out why?
表已正确创建，但 ALTER TABLE 不起作用。不知道为什么？
I used this as reference http://www.w3schools.com/sql/sql_foreignkey.asp
我用这个作为参考http://www.w3schools.com/sql/sql_foreignkey.asp
Error 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '( ADD CONSTRAINT userPropertie FOREIGN KEY(properties) REFERENCES Properties(' at line 2
错误 1064 - 您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以获取在“( ADD CONSTRAINT userPropertie FOREIGN KEY(properties) REFERENCES Properties(' at line 2
回答by Andomar
Omit the parenthesis:
省略括号：
ALTER TABLE User
ADD CONSTRAINT userProperties
FOREIGN KEY(properties)
REFERENCES Properties(ID)
回答by Vladimir Salguero
ALTER TABLE `User`
ADD CONSTRAINT `user_properties_foreign`
FOREIGN KEY (`properties`)
REFERENCES `Properties` (`ID`)
ON DELETE NO ACTION
ON UPDATE NO ACTION;
