Mybatis-Plus自动填充

8 mp实现自动填充.png

1.数据库表中添加自动填充字段

在User表中添加datetime类型的新的字段 create_time、update_time

2.实体上添加注解

@Data

public class User {
    ......
        
    @TableField(fill = FieldFill.INSERT)
    private Date createTime;
    //@TableField(fill = FieldFill.UPDATE)
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Date updateTime;
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}

3.实现元对象处理器接口

元对象就是数据库的原始数据
注意：不要忘记添加 @Component 注解

package com.atguigu.mybatisplus.handler;
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.util.Date;
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
    private static final Logger LOGGER = LoggerFactory.getLogger(MyMetaObjectHandler.class);
    @Override
    public void insertFill(MetaObject metaObject) {
        LOGGER.info("start insert fill ....");
        this.setFieldValByName("createTime", new Date(), metaObject);
        this.setFieldValByName("updateTime", new Date(), metaObject);
    }
    @Override
    public void updateFill(MetaObject metaObject) {
        LOGGER.info("start update fill ....");
        this.setFieldValByName("updateTime", new Date(), metaObject);
    }
}