查詢指定的鍵

db.集合名稱.find({查詢條件},{指定鍵})
指定鍵：1表示顯示，0表示不顯示，_id默認顯示

db.student.find({},{name:1})
{ "_id" : 1, "name" : "zhangsan" }
{ "_id" : 2, "name" : "lisi" }
{ "_id" : 3, "name" : "wangwu" }
{ "_id" : 4, "name" : "zhaoliu" }
{ "_id" : 5, "name" : "qianliu" }
{ "_id" : 6, "name" : "sunba" }
db.student.find({},{_id:0, age:0})
{ "name" : "zhangsan", "sex" : 1 }
{ "name" : "lisi" }
{ "name" : "wangwu" }
{ "name" : "zhaoliu" }
{ "name" : "qianliu" }
{ "name" : "sunba" }
db.student.find({},{_id:0, name:1})
{ "name" : "zhangsan" }
{ "name" : "lisi" }
{ "name" : "wangwu" }
{ "name" : "zhaoliu" }
{ "name" : "qianliu" }
{ "name" : "sunba" }

db.集合名稱.findOne({查詢條件},{指定鍵})

查詢出符合條件的第一條數據

db.student.findOne()
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
db.集合名稱.find({查詢條件},{指定鍵}).limit(數字)查詢前幾條數據

db.student.find().limit(3)
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
db.集合名稱.find({查詢條件},{指定鍵}).skip(數字)跳過前幾條數據

db.student.find().skip(2)
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : 7, "age" : 70 }

可以使用limit()和skip()實現分頁

db.student.find().skip(0).limit(3)
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
db.student.find().skip(3).limit(3)
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
db.student.find().skip(6).limit(3)
{ "_id" : 7, "name" : 7, "age" : 70 }

db.集合名稱.find().sort({鍵:數字})數字為1表示升序，數字為2表示降序

db.student.find().sort({age:1})

{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 7, "name" : 7, "age" : 70 }

db.student.find().sort({age:1, _id:-1})

{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 7, "name" : 7, "age" : 70 }