springboot实体类注解

User

package com.rzy.sbtwebdemo.model;

import javax.persistence.*;
import java.util.Date;


    @Entity 
    @Table(name="t_users")
    public class User {
        private  int id;
        private  String username;
        private  String password;
        private Date regDate;
        private  Address address;

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public String getUsername() {
            return username;
        }

        public void setUsername(String username) {
            this.username = username;
        }

        public String getPassword() {
            return password;
        }

        public void setPassword(String password) {
            this.password = password;
        }
        @Column(name="reg_date")
            public Date getRegDate() {
                return regDate;
            }

            public void setRegDate(Date regDate) {
                this.regDate = regDate;
            }

        @ManyToOne
        @JoinColumn(name="address_id")
            public Address getAddress() {
                return address;
            }

            public void setAddress(Address address) {
                this.address = address;
            }

        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    ", regData=" + regDate +
                    ", address=" + address +
                    '}';
        }
    }

注解

@Entity：表明User是一个实体类，它默认对应数据库中的表名是user，你也可以指定@Entity(name = "t_users")，或者@Table(name="t_users")

@Id注释指定表的主键， @GeneratedValue(strategy = GenerationType.IDENTITY)自增长主键生成策略

 		@Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)

@Column注释定义了将成员属性映射到关系表中的哪一列和该列的结构信息，如@Column(name="reg_date")，将实体类regDate对应数据库中的reg_date。

@Column(name="reg_date")

@ManyToOne：多（User)对一(Address)

@JoinColumn(name=“address_id”)：指定Address主键

 		@ManyToOne
        @JoinColumn(name="address_id")

Address

package com.rzy.sbtwebdemo.model;

import javax.persistence.*;

    @Entity
    @Table(name="t_address")
    public class Address {
        private int id;
        private String addressInfo;
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }
        @Column(name="address_info")
        public String getAddressInfo() {
            return addressInfo;
        }

        public void setAddressInfo(String addressInfo) {
            this.addressInfo = addressInfo;
        }

        @Override
        public String toString() {
            return "Address{" +
                    "id=" + id +
                    ", addressInfo='" + addressInfo + '\'' +
                    '}';
        }
    }

标记为实体类，指定其对应表t_address

	 	@Entity
	    @Table(name="t_address")

标记为主键，指定为自增长主键生成策略

 		@Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)

将addrss中的addressInfo对应与表address_info

		@Column(name="address_info")