Mybatisplus条件结构器QueryWrapper
QueryWrapper：Entity 对象封装操作类
LambdaQueryWrapper ：用于Lambda语法应用的查问Wrapper
例：
QueryWrapper<User> queryWrapper = QueryGenerator.initQueryWrapper(user,null); queryWrapper.eq("user_name",user.getUserName()); IPage<User> page = new Page<>(pageNo, pageSize); IPage<User> pageList = userServer.page(page, queryWrapper);例：
protected FrfReptPlan getFrfReptPlan(String contractId,String perdNum,String costType){ return frfReptPlanService.getOne(new LambdaQueryWrapper<FrfReptPlan>() .eq(FrfReptPlan::getFpfContrId, contractId) .eq(FrfReptPlan::getPerdNum, perdNum) .eq(FrfReptPlan::getCostType,costType));}罕用办法：
办法 形容 等价 例子eq 等于 = eq("name","吕布")name="吕布"ne 不等于 <> ne("name","吕布")含意：name<>"吕布"gt 大于 > gt("age","10")含意：age>10lt 小于 < lt("age","10")含意：age<10ge 大于等于 >= ge("age","10")含意：age>=10le 小于等于 <= le("age","10")含意：age<=10between 在值1值2之间 between and between("age","10","18")含意：10<=age<=18notBetween 不在值1值2之间 not bteween and notBetween("age","10","18")含意：18<age或age<10like 含糊查问 like like("name","吕")含意：name like "%吕%"notLike 含糊查问 not Like notLike("name","吕")含意：name not like "%吕%"likLeft 含糊查问 likLeft("name","吕")含意：name like "%吕"likeRight 含糊查问 likeRight("name","吕")含意：name like "吕%"isNull 是否为空isNotNull 字段为不空in in in age in (10,15,20)含意：age在10,15,20之间notIn not in not in age not in (10,15,20)含意：age不在10,15,20之间inSql in(sql) inSql("id","select id from table")含意：id in (select id from table)notInSql not in(sql) notInSql("id","select id from table")含意：id not in (select id from table)groupBy 分组 group by groupBy(id,name)含意：group by id,nameorderByAsc 升序 orderByAsc(id,name)含意：order by id asc,name ascorderByDesc 降序 orderByDesc(id,name)含意：order by id desc,name descorderBy 排序 order by orderBy(true,true,"id","name")含意：order by id asc,name aschaving havingor 或 or eq("id","1") or eq("id","2")含意：id='1' or id='2'and 且 and eq("id","1") and eq("id","2")含意：id='1' and id='2'apply 拼接sqllast 忽视优化规定间接拼接sql最初exists 拼接notExists 拼接nested 失常嵌套，不带and或者or