Mongodb入门2

$push 修饰符：用于往数组中追加元素

 db.workmates.update({name:'xiaowang'},{$push:{interseta:"PHP"}}) 

 

$ne 修饰符：如果 选择字段的值不等于给定的值或者该字段不存在

selects the documents where the value of the field is not equal to the specified value. This includes documents that do not contain the field.

> db.c1.find()
{ "_id" : ObjectId("4fb4af85afa87dc1bed94330"), "age" : 7, "length_1" : 30 }
{ "_id" : ObjectId("4fb4af89afa87dc1bed94331"), "age" : 8, "length_1" : 30 }
{ "_id" : ObjectId("4fb4af8cafa87dc1bed94332"), "age" : 6, "length_1" : 30 }

// 查询age 的值不等于7 的数据
> db.c1.find( { age : { $ne : 7 } } );
{ "_id" : ObjectId("4fb4af89afa87dc1bed94331"), "age" : 8, "length_1" : 30 }
{ "_id" : ObjectId("4fb4af8cafa87dc1bed94332"), "age" : 6, "length_1" : 30 }

 $addToSet 修饰符：向数组中添加一个值，如果该值存在，则不进行任何操作。

The $addToSet operator adds a value to an array unless the value is already present, in which case $addToSet does nothing to that array.

> db.c1.find()
{ _id: 1, letters: ["a", "b"] }

// 执行$addToSet
db.c1.update({_id:1},{$addToSet:{
    letters:"c"
}})

$each 修饰符：向数组中批量添加值

可以结合$addToSet 和 $push 使用

db.students.update(
   { name: "joe" },
   { $push: { scores: { $each: [ 90, 92, 85 ] } } }
)

 

数组定位修改

修改数组索引为2的值为"code"

db.workmates.update({name:'xiaowang'},{$set:{"interset.2":"code"}})

runCommand

您可以使用 MongoDatabase.runCommand() 方法运行所有原始数据库操作，并返回执行结果

findAndModify

修改并返回单个文档，如果需要返回修改后的，需要指定new 为true

var myModify = {
    findAndModify: "workmates",
    query: { name: "xiaowang" },
    update:{$set:{age:10}},
    new:true, //返回修改后的值
    fields:{name:true,age:true} // 需要返回的值
};

var result = db.runCommand(myModify);

查询操作

// 虚拟的文档数据：
var db = connect("company");
function WorkMate(name, age, skill) {
    this.name = name;
    this.age = age;
    this.skill = skill;
}

var nameList = ["慎", "嘉文四世", "赵信", "德莱厄斯", "易", "贾克斯"];
var ageList = [20, 30, 40, 33, 22, 55];
var skillList = [
    ["奥义！暮临", "奥义！魂佑", "奥义！影缚", "秘奥义！慈悲度魂落"],
    ["巨龙撞击", "黄金圣盾", "德玛西亚军旗", "天崩地裂"],
    ["三重爪击", "狂战怒吼", "无畏冲锋", "新月横扫"],
    ["大杀四方", "致残打击", "无情铁手", "诺克萨斯断头台"],
    ["阿尔法突袭", "冥想", "无极剑道", "高原血统"],
    ["跳斩", "蓄力一击", "反击风暴", "宗师之威"],
];

var start = 6;
var heros = []
while (start-- > 0) {
    heros.push(
        new WorkMate(nameList[start],ageList[start],skillList[start])
    )
}

db.heros.insert(heros);

print('INSERT SUCCESS');

// 查询操作

var db = connect("company");

// 精确查询
db.heros.find({
    name:'贾克斯'
});

// 查询年龄大于30 小于等于50的

db.heros.find({
    age:{$gt:30,$lte:50}
})

// 查询年龄不等于33的
db.heros.find({
    age:{$ne:33},
})

// 查询名称不等于赵信的
db.heros.find({
    name:{$ne:"赵信"},
},{
    name:1
})

// 从查询结果取出自己需要的字段
db.heros.find({
    name:'贾克斯'
},{
    name:1,
    age:1,
    _id:0
});