using mongodb advanced command 2

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#分页，只显示指定的条数

db.cuser.find({age:{$ne:5}}).limit(5);

#跳过3个 然后显示5条数据

db.cuser.find({age:{$ne:5}}).skip(3).limit(5);

#显示集合中一共有多少条数据

> db.cuser.count();
8
> db.cuser.find().count();
8

#mongodb排序 1升序 2降序

db.cuser.find().sort({age:-1});#按年龄降序

db.cuser.find().sort({age:1});#按年龄升序

#条件为age不等于5,从第四个开始,显示5条数据 升序 可用于分页

db.cuser.find({age:{$ne:5}}).skip(3).limit(5).sort({age:1});;

#统计个数

db.cuser.find({age:{$ne:5}}).skip(3).limit(5).sort({age:1}).count(0);

上面等于

db.cuser.find({age:{$ne:5}}).skip(3).limit(5).sort({age:1}).count();

db.cuser.find().count();#所有的数据

#按条件筛选后还有多少条

db.cuser.find({age:{$ne:5}}).skip(3).limit(5).sort({age:1}).count(1);;

skip(),sort(), limit();使用不分先后

#包含 $all

db.cuser.find({age:{$all:[3]}});
{ "_id" : ObjectId("51a23348ea214a8ee3204de3"), "name" : "userid_3", "pwd" : "pwd_3", "age" : 3 }

#先更新数据 添加一个用户提交帖子内容

db.cuser.update({name:"userid_1"},{$set:{post:[1,2,3,4,5]}});

#查找帖子包含1,2,3的数据
> db.cuser.find({post:{$all:[1,2,3]}});
{ "_id" : ObjectId("51a23348ea214a8ee3204de1"), "age" : 1, "name" : "userid_1", "post" : [ 1, 2, 3, 4, 5 ], "pwd" : "pwd_1" }

#取模的 $mod 年龄 

db.cuser.find({age:{$mod:[2,1]}});#取2 余1的 

#取2 余1的输出结果

db.cuser.find({age:{$mod:[2,1]}});
{ "_id" : ObjectId("51a23348ea214a8ee3204de3"), "name" : "userid_3", "pwd" : "pwd_3", "age" : 3 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de5"), "name" : "userid_5", "pwd" : "pwd_5", "age" : 5 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de7"), "name" : "userid_7", "pwd" : "pwd_7", "age" : 7 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de1"), "age" : 1, "name" : "userid_1", "post" : [ 1, 2, 3, 4, 5 ], "pwd" : "pwd_1" }

#取2 余0的输出结果
> db.cuser.find({age:{$mod:[2,0]}});
{ "_id" : ObjectId("51a23348ea214a8ee3204de2"), "name" : "userid_2", "pwd" : "pwd_2", "age" : 2 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de4"), "name" : "userid_4", "pwd" : "pwd_4", "age" : 4 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de6"), "name" : "userid_6", "pwd" : "pwd_6", "age" : 6 }
{ "_id" : ObjectId("51a23348ea214a8ee3204de8"), "name" : "userid_8", "pwd" : "pwd_8", "age" : 8 }