Spring Jpa 自动建表——表字段设置默认值

表字段设置默认值

• 记录意义：学习记录
• 方法一：使用@Column注解中的columnDefinition属性设置默认值
  • 代码如下

@Entity
@Table(name = "m_test")
@DynamicInsert
@DynamicUpdate
public class TestTable implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", columnDefinition = "BIGINT")
    private Long id;

    @Column(name = "user_name", columnDefinition = "varchar(50) NOT NULL COMMENT '用户名称'")
    private String userName;

    @Column(name = "address", columnDefinition = "varchar(50) NOT NULL COMMENT '用户地址'")
    private String address;
    
    @Column(name = "sex", columnDefinition = "tinyint NOT NULL DEFAULT 0 COMMENT '性别：0-男  1-女'")
    private Integer sex;

}

• • 注意：在使用这个方法设置字段默认值时，如果定义了NOT NULL，则要在使用类注解@DynamicInsert和@DynamicUpdate，否则报错

• 方法二：直接为类属性设置值
  • 代码如下

@Entity
@Table(name = "m_test")
public class TestTable implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", columnDefinition = "BIGINT")
    private Long id;

    @Column(name = "user_name", columnDefinition = "varchar(50) NOT NULL COMMENT '用户名称'")
    private String userName;
    
    @Column(name = "address", columnDefinition = "varchar(50) NOT NULL COMMENT '用户地址'")
    private String address;
    
    @Column(name = "sex", columnDefinition = "tinyint NOT NULL'")
    private Integer sex = 0;

}

• 建议：使用方法二

时间类型

• 记录意义：在数据库设置时间类型时，有的使用timestamp ，有的使用datetime，个人推荐使用datetime
• 代码如下

@Entity
@Table(name = "m_test")
public class TestTable implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", columnDefinition = "BIGINT")
    private Long id;

    @Column(name = "user_name", columnDefinition = "varchar(50) NOT NULL COMMENT '用户名称'")
    private String userName;
    
    @Column(name = "address", columnDefinition = "varchar(50) NOT NULL COMMENT '用户地址'")
    private String address;
    
    @Column(name = "sex", columnDefinition = "tinyint NOT NULL'")
    private Integer sex = 0;

    @JsonFormat
    @Column(name = "cdate", columnDefinition = "DATETIME DEFAULT CURRENT_TIMESTAMP ")
    private LocalDateTime cdate = LocalDateTime.now();

    @JsonFormat
    @Column(name = "mdate", columnDefinition = "DATETIME DEFAULT CURRENT_TIMESTAMP ")
    private LocalDateTime mdate = LocalDateTime.now();

}