我是新的Spring Boot和这样的事情，这是第一个项目，我试图探索和以下讲座项目创建，我做了一个实体类与@Entity和@Table注解，当我执行项目，两个表在mysql数据库得到创建即blog和blog_seq，我想了解这个blog_seq是如何创建的，以及它对这个表的意义是什么。
Entity类：

package com.SpringBoot.blog.entity;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.Table;
import jakarta.persistence.UniqueConstraint;

@Entity
@Table(name = "posts", uniqueConstraints = {@UniqueConstraint(columnNames = {"titles"})})
public class Posts {
        @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    @Column(name = "titles", nullable = false)
    private String title;
    @Column(name = "description", nullable = false)
    private String description;
    @Column(name = "content", nullable = false)
    private String content;

    public Posts() {
        super();
    }

    public Posts(long id, String title, String description, String content) {
        super();
        this.id = id;
        this.title = title;
        this.description = description;
        this.content = content;
    }

    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
 
}

application.properties：

spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/blog
spring.datasource.userName=root
spring.datasource.password=123456789
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

mysql工作台：

谢谢你的帮助！！
尝试稍微更改实体注解和application.properties，但不起作用。