关于java:Mybatisplus条件构造器QueryWrapper

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>10
lt            小于            <               lt("age","10")含意：age<10
ge            大于等于        >=              ge("age","10")含意：age>=10
le            小于等于        <=              le("age","10")含意：age<=10
between       在值1值2之间    between and     between("age","10","18")含意：10<=age<=18
notBetween    不在值1值2之间 not bteween and  notBetween("age","10","18")含意：18<age或age<10
like          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,name
orderByAsc    升序                            orderByAsc(id,name)含意：order by id asc,name asc
orderByDesc   降序                            orderByDesc(id,name)含意：order by id desc,name desc
orderBy       排序           order by         orderBy(true,true,"id","name")含意：order by id asc,name asc
having        having
or            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sql
last          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