ให้เราสร้างคอลเลกชันที่มีเอกสารก่อน -
> db.demo373.createIndex({"Name":1,"CountryName":1}); { "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > db.demo373.insertOne({"Name":"Chris","Age":22,"CountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5e59ffde2ae06a1609a00aff") } > db.demo373.insertOne({"Name":"David","Age":21,"CountryName":"AUS"}); { "acknowledged" : true, "insertedId" : ObjectId("5e59ffe82ae06a1609a00b00") } > db.demo373.insertOne({"Name":"Bob","Age":23,"CountryName":"UK"}); { "acknowledged" : true, "insertedId" : ObjectId("5e59fff42ae06a1609a00b01") } > db.demo373.insertOne({"Name":"John","Age":21,"CountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5e59ffff2ae06a1609a00b02") } > db.demo373.insertOne({"Name":"Carol","Age":23,"CountryName":"AUS"}); { "acknowledged" : true, "insertedId" : ObjectId("5e5a00082ae06a1609a00b03") }
แสดงเอกสารทั้งหมดจากคอลเล็กชันโดยใช้วิธี find() -
> db.demo373.find();
สิ่งนี้จะสร้างผลลัพธ์ต่อไปนี้ -
{ "_id" : ObjectId("5e59ffde2ae06a1609a00aff"), "Name" : "Chris", "Age" : 22, "CountryName" : "US" } { "_id" : ObjectId("5e59ffe82ae06a1609a00b00"), "Name" : "David", "Age" : 21, "CountryName" : "AUS" } { "_id" : ObjectId("5e59fff42ae06a1609a00b01"), "Name" : "Bob", "Age" : 23, "CountryName" : "UK" } { "_id" : ObjectId("5e59ffff2ae06a1609a00b02"), "Name" : "John", "Age" : 21, "CountryName" : "US" } { "_id" : ObjectId("5e5a00082ae06a1609a00b03"), "Name" : "Carol", "Age" : 23, "CountryName" : "AUS" }
ต่อไปนี้เป็นแบบสอบถามเพื่อใช้ดัชนีและการเรียงลำดับด้วยการแบ่งหน้าใน MongoDB -
> db.demo373.find().sort({"Name":1, "Age":1}).limit(4).skip(2);
สิ่งนี้จะสร้างผลลัพธ์ต่อไปนี้ -
{ "_id" : ObjectId("5e59ffde2ae06a1609a00aff"), "Name" : "Chris", "Age" : 22, "CountryName" : "US" } { "_id" : ObjectId("5e59ffe82ae06a1609a00b00"), "Name" : "David", "Age" : 21, "CountryName" : "AUS" } { "_id" : ObjectId("5e59ffff2ae06a1609a00b02"), "Name" : "John", "Age" : 21, "CountryName" : "US" }