>db.mediaCollection.insert({"Type":"DVD",Title:"Toy Story 3",Released:2010}) 2. $gt (greater than) 1 2 3 4 5 6 7 8 9 >db.mediaCollection.find({Released:{$gt:2000}},{"Cast":0}).toArray() [ { "_id":ObjectId("53548254d85b463e729a2e59"), "Type":"DVD", "Title":"To...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 db.things.find( { x : { $ne : 3 } } ); in 和 not in ($in $nin) 语法: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 db.collection.find( { "field" : { $in : array } } ); ...
"id":51803, "ctx":"conn31","msg":"Slow query","attr":{"type":"command","ns":"test.test2","appName":"MongoDB Shell","command":{"find":"test2","filter":{"id":12},"lsid":{"id":{"$uuid":"60e64fb3-900e-4dc4-8295-0b41f30f9782"}},"$clusterTime":{"clusterTime":{"...
varsexMapFun=function(){// 定义好了分组的条件,以及每个集合要取出的内容emit(this.sex,{"ccount":1,"csal":this.salary,"cmax":this.salary,"cmin":this.salary,"cname":this.name});};varsexReduceFun=function(key,values){vartotal=0;// 统计varsum=0;// 计算总工资varmax=values[0].cmax;//...
大于等于($gte):Greater than equals db.qtfm__audio_info.find({playLength:{$gte:2}}) 不等于($ne):Not equals db.qtfm__audio_info.find({name:{$ne:'11'}}) 小于等于($lte):Less than equals db.getCollection("qtfm__audio_info").find({playLength:{$lte:22},code:"TT0000066_0001",'al...
$arrayElemAt会根据第二个参数从数组中选择特定元素。在本例中,1值会从$split运算符生成的数组中选择第二个元素,因为数组索引会从0开始。例如,传递给此操作的值 ["Store", "42"] 将返回值“42”。 constresult =awaitplants.aggregate([ { $project: { ...
db.stu.find({name:"Jerry",age:18})[0] 1. findOne()返回的就是一个文档,相当于find(<条件>)[0] findOne()可以直接在最后指定某一条属性,例如findOne(<条件>).name find(<条件>).count() , find(<条件>).length() 可以得到满足条件文档的数量 ...
3. $gte(greater than or equal to) > db.mediaCollection.find( { Released : {$gte : 1999 } }, { "Cast" : 0 } ).toArray() [ { "_id" : ObjectId("53548225d85b463e729a2e57"), "Type" : "DVD", "Title" : "Matrix, The", "Released" : 1999 }, { "_id" : ObjectId("5354...
我试图找到数组字段的和,然后,想过滤大于100的和。 { name: 'John', grades: [60, 70, 40] # sum of this array = 170 (take this) }, { name: 'Doe', grades: [30, 20, 10] # sum of this array = 60 (don't take this)
Length of Database Names Database names cannot be empty and must be less than 64 bytes. Restriction on Collection Names Collection names should begin with an underscore or a letter character, andcannot: contain the$. be an empty string (e.g.""). ...