Question

1用户应该有很多邮件，但是当我运行spring boot应用程序时，它不会创建我的邮件表。（它会创建用户，角色，users_roles，users_mails）

我的用户类。我尝试使用mappingBy =“ user”，但是我也没有创建users_mail表。

@Entity
@Table(name="users")
public class User {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String firstName;
private String lastName;
private String email;
private String password;

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinTable(
        name = "users_roles",
        joinColumns = @JoinColumn(
                name = "user_id", referencedColumnName = "id"),
        inverseJoinColumns = @JoinColumn(
                name = "role_id", referencedColumnName = "id"))
private Collection < Role > roles;

@OneToMany
private List<Mail > mails;

public User() {}

public User(String firstName, String lastName, String email, String password, Collection<Role> roles, List<Mail> mails) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
    this.password = password;
    this.roles = roles;
    this.mails = mails;
}

}

我的角色课程。

@Entity
@Table(name="roles")
public class Role {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;

public Role() {}

}

我的邮件班级。

@Entity
@Table(name="mails")
public class Mail {

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private long id;

@ManyToOne
private User user;

private String subject;
private String from;
private String text;

public Mail() {
}

public Mail(String destination,String subject, String text) {
    this.from = destination;
    this.subject=subject;
    this.text = text;
}

}

我的application.properties。请不要告诉我使用... ddl-auto = update。头疼。

spring.mvc.view.prefix=/WEB-INF/jsp/ spring.mvc.view.suffix=.jsp spring.datasource.url = jdbc:mysql://localhost:3306/users_app?useSSL=false spring.datasource.username = root spring.datasource.password = 123456 spring.jpa.generate-ddl=true spring.jpa.hibernate.ddl-auto=create-drop spring.jpa.show-sql=true spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5InnoDBDialect

我的代码错误：：GenerationTarget遇到异常接受命令：通过JDBC语句执行DDL错误

org.hibernate.tool.schema.spi.CommandAcceptanceException：通过JDBC语句执行DDL错误

休眠：更改表users_mails删除外键FKl5thenbbsfpv2fv7etw9o800n 2019-04-30 19：31：27.017 WARN 7004 --- [restartedMain] o.h.t.s.i.ExceptionHandlerLoggedImpl：GenerationTarget遇到异常接受命令：通过JDBC语句执行DDL错误

产生原因：com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：无法删除'FKl5thenbbsfpv2fv7etw9o800n';检查列/键是否存在

但是它开始了。

....在8.654秒内启动MailApplication（JVM运行9.887）

无法打开引用表“邮件”

0 个答案: