java - 创建 SQL 表时出错。埃类类

Question

我尝试创建一个 Transaction SQL 表，其中包含来自另外两个表的两个外键:User 和 Car。
Car.java

@Entity
public class Car extends Model{

    @Id
    @GeneratedValue
    public int id; 
    @ManyToOne
    @JoinColumn(name="user_fk")
    public User user; 
    @OneToOne(cascade=CascadeType.ALL, mappedBy="car")
    public Transaction transaction; 
}

User.java

@Entity
public class User extends Model{

    @Id
    @GeneratedValue
    public int id;  
    @OneToMany(cascade=CascadeType.ALL, mappedBy="user") // If we delete a user, all the object belongs to this user are deleted. 
    public List<Car> cars = new ArrayList<Car>();
    @OneToOne(cascade=CascadeType.ALL, mappedBy="user")
    public Transaction transaction; 
}

Transaction.java

@Entity
@Table(name = "transactions")
public class Transaction extends Model{

    @Id
    @GeneratedValue
    public int id; 
    @OneToOne
    @JoinColumn(name = "user_fk")
    public User user; 
    @OneToOne
    @JoinColumn(name = "car_fk")
    public Car car; 
}

这是生成的transactions表脚本

create table transactions (
id                        integer not null,
user_fk                   integer,
car_fk                    integer,
from                      timestamp,
to                        timestamp,
availability              boolean,
constraint pk_transactions primary key (id))

alter table transactions add constraint fk_transactions_user_4 foreign key (user_fk) references user (id) on delete restrict on update restrict;
create index ix_transactions_user_4 on transactions (user_fk);
alter table transactions add constraint fk_transactions_car_5 foreign key (car_fk) references car (id) on delete restrict on update restrict;
create index ix_transactions_car_5 on transactions (car_fk);

我收到以下错误:

Syntax error in SQL statement "CREATE TABLE TRANSACTIONS ( ID INTEGER NOT NULL, USER_FK INTEGER, CAR_FK INTEGER, FROM[*] TIMESTAMP, TO TIMESTAMP, AVAILABILITY BOOLEAN, CONSTRAINT PK_TRANSACTIONS PRIMARY KEY (ID)) "; expected "identifier"; SQL statement: create table transactions ( id integer not null, user_fk integer, car_fk integer, from timestamp, to timestamp, availability boolean, constraint pk_transactions primary key (id)) [42001-175] [ERROR:42001, SQLSTATE:42001], while trying to run this SQL script

我做错了什么？

Answer 1

CREATE TABLE TRANSACTIONS ( 
ID INTEGER NOT NULL, 
USER_FK INTEGER, 
CAR_FK INTEGER, 
FROM[*] TIMESTAMP, 
TO TIMESTAMP, 
AVAILABILITY BOOLEAN, 
CONSTRAINT PK_TRANSACTIONS PRIMARY KEY (ID))

错误是使用 FROM 作为列名。 FROM 是保留字，绝对没有理由使用保留字作为列名 http://dev.mysql.com/doc/refman/5.5/en/reserved-words.html 。因此，只需选择一个不是保留字的名称即可。