Question

$in 修饰符

$in 修饰符可以轻松解决一键多值的查询情况。和 $in 相对的修饰符是 $nin ，即查询除了 $in 条件以外的值。

// 查询年龄是 10 或者 13 的学生
> db.student.find(
    age: {$in:[10, 13]}},
    {name:1, age:1, _id:0}
)
{ "name" : "lisi", "age" : 10 }
{ "name" : "xiaohong", "age" : 13 }

$nin ：

> db.student.find( {age: {$nin:[10,13]}},{name:1,age:1,_id:0} )
{ "name" : "wangwu", "age" : 12 }
{ "name" : "xiaohua", "age" : 12 }
{ "name" : "zhaoliu", "age" : 12 }
{ "name" : "xiaoli", "age" : 12 }
{ "name" : "xiaoliu", "age" : 12 }
{ "name" : "zhangsan", "age" : 12 }
{ "name" : "lihua", "age" : 12 }
{ "name" : "xiaozhang", "age" : 12 }

$or 修饰符

$or 修饰符用来查询多个键值的情况，就比如查询学生中大于等于 13 岁或者 hobbyOne 是篮球，而 $in 修饰符是用于一个 Key 值的情况，相对应的还有 $nor 修饰符。

> db.student.find( {$or: [ {age: {$gte: 13}}, {"hobby.hobbyOne": "篮球"} ]}, {name:1,hobby:1,age:1,_id:0} )
{ "name" : "lisi", "age" : 10, "hobby" : { "hobbyOne" : "篮球", "hobbyTwo" : "足球", "hobbyThree" : "羽毛球" } }
{ "name" : "xiaohong", "age" : 13, "hobby" : { "hobbyOne" : "瑜伽", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }
{ "name" : "lihua", "age" : 12, "hobby" : { "hobbyOne" : "篮球", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }

$nor ：

// 筛选年龄小于 13 且 hobbyOne 不是篮球的学生
> db.student.find( {$nor: [ {age: {$gte: 13}}, {"hobby.hobbyOne": "篮球"} ]}, {name:1,hobby:1,age:1,_id:0} )
{ "name" : "wangwu", "age" : 12, "hobby" : { "hobbyOne" : "游泳", "hobbyTwo" : "健身", "hobbyThree" : "乒乓球" } }
{ "name" : "xiaohua", "age" : 12, "hobby" : { "hobbyOne" : "体操", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }
{ "name" : "zhaoliu", "age" : 12, "hobby" : { "hobbyOne" : "音乐", "hobbyTwo" : "美术", "hobbyThree" : "书法" } }
{ "name" : "xiaoli", "age" : 12, "hobby" : { "hobbyOne" : "体操", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }
{ "name" : "xiaoliu", "age" : 12, "hobby" : { "hobbyOne" : "钓鱼", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }
{ "name" : "zhangsan", "age" : 12, "hobby" : { "hobbyOne" : "足球", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }
{ "name" : "xiaozhang", "age" : 12, "hobby" : { "hobbyOne" : "乒乓球", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }

$and 修饰符

$and 用来查找几个 key 值都满足的情况。

// 筛选年龄大于等于 13 且 hobbyOne 是篮球的学生
> db.student.find( {$and: [ {age: {$gte: 13}}, {"hobby.hobbyOne": "瑜伽"} ]}, {name:1,hobby:1,age:1,_id:0} )
{ "name" : "xiaohong", "age" : 13, "hobby" : { "hobbyOne" : "瑜伽", "hobbyTwo" : "跳舞", "hobbyThree" : "书法" } }

$not 修饰符

$not 修饰符用来查询除条件之外的值。

// 查询除了大于等于 11，小于等于 12 的学生，即查询小于 11 或者大于 12 的学生
> db.student.find({
... age:{
... $not:{
... $lte:12,
... $gte:11
... }}},
... {name:1,age:1,_id:0})
{ "name" : "lisi", "age" : 10 }
{ "name" : "xiaohong", "age" : 13 }