@TableId(type=IdType.AUTO) 声明主键自增长 @TableId(type=IdType.AUTO) //声明主键自增长 @TableField(select = false) //查询时，则不返回该字段的值 @TableField(value = "email") //通过tableField进行字段不一致的映射 @TableField(exist = false) //设置该字段在数据库表中不存在 @TableField(update="now()") //使用数据库时间输出 SQL 为：update 表 set 字段=now() where ... //TableField 注解新增属性 condition 预处理 WHERE 实体条件自定义运算规则，下面会有代码讲解 @TableField(condition = SqlCondition.LIKE) private String name; //输出 SQL 为：select 表 where name LIKE CONCAT('%',值,'%')

MybatisPlus 分页插件 配置 //Spring boot方式 @Configuration @MapperScan("com.baomidou.cloud.service.*.mapper*") public class MybatisPlusConfig { // 旧版 @Bean public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); } // 最新版 @Bean public MybatisPlusInterceptor mybatisPlusInterceptor() { MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor(); interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.H2)); return interceptor; } } 使用

QueryWrapper 常用方法 AbstractWrapper 下的方法及使用 方法名 说明 使用 allEq(Map<R, V> params) 全部 =(或个别 isNull) allEq(params,true) eq = eq("real_name”,"王昭君”) ne <> ne("nick_name”,"空想 4”) gt > gt("age”,21) ge >= ge("age”,22) lt < lt("age”,22) le <= le("age”,21") between cloum between ? and ? between("age”,0,21) notBetween cloum between ? and ? notBetween("age”,0,21) like cloum like '% 王 %’ like("real_name”,"王”) notLike not like '% 王 %’ notLike("real_name”,"王”) likeLeft like '% 王’ likeLeft("real_name”,"昭”) likeRight like '王 %’ likeRight("real_name”,"昭”) isNull is null isNull("gender”) isNotNull is not null isNotNull("gender”) in in (1,2,3) in("nick_name”,lists) notIn age not in (1,2,3) notIn("nick_name”,lists) inSql age in (1,2,3,4,5,6) inSql("nick_name”,"'空想 4’,'空想 5’,'空想 6’") notInSql age not in (1,2,3,4,5,6) notInSql("nick_name”,"'空想 4’,'空想 5’,'空想 6’") groupBy group by id,name groupBy("nick_name”,"age”) orderByAsc order by id ASC,name ASC orderByAsc("nick_name”,"age”) orderByDesc order by id DESC,name DESC orderByDesc("age”) orderBy order by id ASC,name ASC orderBy(true,true,"age”) having having sum(age) > 10 having("sum(age) > 10”) or id = 1 or name = '老王’ eq("nick_name”,"空想 4”).or(i->i.eq("age”,21) eq("nick_name”,"空想 4”).or().eq("nick_name”,"空想 5”) and and (name = '李白’ and status <> '活着’) and(i->i.eq("age”,21)) nested (name = '李白’ and status <> '活着’) nested(i->i.eq("age”,21).eq("nick_name”,"空想 4”)) apply id = 1 apply("nick_name = '空想 4’”) last 最后添加多个以最后的为准，有 sql 注入风险 last("limit 1”) exists 拼接 EXISTS (sql 语句) exists("select id from table where age = 1”) notExists 拼接 NOT EXISTS (sql 语句) notExists("select id from table where age = 1”)

乐观锁插件 1 ，注册组件 // Spring Boot 方式 @Configuration @MapperScan("按需修改") public class MybatisPlusConfig { /** * 旧版 */ @Bean public OptimisticLockerInterceptor optimisticLockerInterceptor() { return new OptimisticLockerInterceptor(); } /** * 新版 */ @Bean public MybatisPlusInterceptor mybatisPlusInterceptor() { MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor(); mybatisPlusInterceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor()); return mybatisPlusInterceptor; } } 2 ，在实体类上 加上 version 属性 并添加set get 加上 @version注解 否则不会自增 @Version private int version; 3 测试类 //查询 模拟线程1 MhysCourse mhysCourse1 = mhysCourseMapper.selectById(1L); //修改 mhysCourse1.setCourseName("乐观锁测试模拟线程1"); //查询 模拟线程2 插队 MhysCourse mhysCourse2 = mhysCourseMapper.selectById(1L); //修改 mhysCourse2.setCourseName("乐观锁测试模拟线程2"); //3,更新 mhysCourseMapper.updateById(mhysCourse2); mhysCourseMapper.updateById(mhysCourse1);