MyBatis-plusSQL语句包装器QueryWrapper，包装器查询倒序返回第一个
CategoryEntity categoryEntity = IotBeanUtil.copy(categoryCreateDTO, CategoryEntity.class);
QueryWrapper<CategoryEntity> wrapper = new QueryWrapper<>();
QueryWrapper<CategoryEntity> sort = wrapper.orderByDesc("sort").last("limit 1");
CategoryEntity sortEntity = categoryDao.selectOne(sort);
简单SQL不想写SQL语句或者复杂SQL不想在Mapper里写时可以Mybatis-plus的包装类，实现自己的业务。可读性差，建议使用xml统一管理，方便别处使用。
| 方法名 | 说明 | 使用 |
| allEq(Map<R, V> params) | 全部=(或个别isNull) | allEq(params,true) |
| eq | = | eq(“table_column”,” 王昭君”) |
| ne | <> | ne(“column”,” 空想4”) |
| gt | > | gt(“table_column”,21) |
| ge | >= | ge(“table_column”,22) |
| lt | < | lt(“table_column”,22) |
| le | <= | le(“table_column”,21”) |
| between | cloum between ? and ? | between(“table_column”,0,21) |
| notBetween | cloum between ? and ? | notBetween(“table_column”,0,21) |
| like | cloum like ‘% 王%’ | like(“table_column”,” 王”) |
| notLike | not like ‘% 王%’ | notLike(“table_column”,” 王”) |
| likeLeft | like ‘% 王’ | likeLeft(“table_column”,” 昭”) |
| likeRight | like ‘ 王%’ | likeRight(“table_column”,” 昭”) |
| isNull | is null | isNull(“table_column”) |
| isNotNull | is not null | isNotNull(“table_column”) |
| in | in (1,2,3) | in(“column”,lists) |
| notIn | age not in (1,2,3) | notIn(“column”,lists) |
| inSql | age in (1,2,3) | inSql(“column”,”‘ 空想4’,‘空想5’,‘空想6’”) |
| notInSql | age not in (1,2,3,4,5,6) | notInSql(“column”,”‘ 空想4’,‘空想5’,‘空想6’”) |
| groupBy | group by id,name | groupBy(“column”,”table_column”) |
| orderByAsc | order by id ASC,name ASC | orderByAsc(“column”,”table_column”) |
| orderByDesc | order by id DESC,name DESC | orderByDesc(“table_column”) |
| orderBy | order by id ASC,name ASC | orderBy(true,true,”table_column”) |
| having | having sum(age) > 10 | having(“sum(age) > 10”) |
| or | id = 1 or name = ‘ 老王’ | eq(“column”,” 空想4”).or(i->i.eq(“table_column”,21) eq(“column”,”空想4”).or().eq(“column”,”空想5”) |
| and | and (name = ‘ 李白’ and status <> ‘活着’) | and(i->i.eq(“table_column”,21)) |
| nested | (name = ‘ 李白’ and status <> ‘活着’) | nested(i->i.eq(“table_column”,21).eq(“column”,” 空想4”)) |
| apply | id = 1 | apply(“table_column” = ‘ 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”) |