mongodbsortlimit和skip用法

来源：动视网责编：小采时间：2020-11-09 13:13:36

mongodbsortlimit和skip用法

mongodbsortlimit和skip用法:检索数据可以使用sort()方法来对数据进行排序，指定排序字段，并使用1或-1来指定排序方式是升序或降序。类似于SQL语句中的order by语句。可以使用limit()方法来读取指定数量的数据，还可以使用skip()方法来跳过指定数量的数据。对分页性能上面效率非常高。1

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导读mongodbsortlimit和skip用法:检索数据可以使用sort()方法来对数据进行排序，指定排序字段，并使用1或-1来指定排序方式是升序或降序。类似于SQL语句中的order by语句。可以使用limit()方法来读取指定数量的数据，还可以使用skip()方法来跳过指定数量的数据。对分页性能上面效率非常高。1

检索数据可以使用sort()方法来对数据进行排序，指定排序字段，并使用1或-1来指定排序方式是升序或降序。类似于SQL语句中的order by语句。可以使用limit()方法来读取指定数量的数据，还可以使用skip()方法来跳过指定数量的数据。对分页性能上面效率非常高。1.

检索数据可以使用sort()方法来对数据进行排序，指定排序字段，并使用1或-1来指定排序方式是升序或降序。类似于SQL语句中的order by语句。可以使用limit()方法来读取指定数量的数据，还可以使用skip()方法来跳过指定数量的数据。对分页性能上面效率非常高。 1. 语法 >db.COLLECTION_NAME.find().sort({KEY:1}) >db.COLLECTION_NAME.find().limit(NUMBER) >db.COLLECTION_NAME.find().limit(NUMBER).skip(NUMBER) 2. sort()

> db.mediaCollection.find().sort({"Tracklist":1}).toArray()
[
 {
 "_id" : ObjectId("5353462f93efef02c962da71"),
 "Type" : "Book",
 "Title" : "Definitive Guide to MongoDB, the",
 "ISBN" : "987-1-4302-3051-9",
 "Publisher" : "Apress",
 "Author" : [
 "Membrey, Peter",
 "Plugge, Eelco",
 "Hawkins, Tim"
 ]
 },
 {
 "_id" : ObjectId("5353462f93efef02c962da72"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind"
 },
 {
 "_id" : ObjectId("5353463193efef02c962da73"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind",
 "Tracklist" : [
 {
 "Track" : "1",
 "Title" : "Smells like teen spirit",
 "Length" : "5:02"
 },
 {
 "Track" : "2",
 "Title" : "In Bloom",
 "Length" : "4:15"
 }
 ]
 }
]
> db.mediaCollection.find().toArray()
[
 {
 "_id" : ObjectId("5353462f93efef02c962da71"),
 "Type" : "Book",
 "Title" : "Definitive Guide to MongoDB, the",
 "ISBN" : "987-1-4302-3051-9",
 "Publisher" : "Apress",
 "Author" : [
 "Membrey, Peter",
 "Plugge, Eelco",
 "Hawkins, Tim"
 ]
 },
 {
 "_id" : ObjectId("5353462f93efef02c962da72"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind"
 },
 {
 "_id" : ObjectId("5353463193efef02c962da73"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind",
 "Tracklist" : [
 {
 "Track" : "1",
 "Title" : "Smells like teen spirit",
 "Length" : "5:02"
 },
 {
 "Track" : "2",
 "Title" : "In Bloom",
 "Length" : "4:15"
 }
 ]
 }
]

注意：如果指定的排序键不存在，那么数值将以它们插入的顺序升序返回。 3. limit() 该函数用来指定返回结果的最大数量。

> db.mediaCollection.find().limit(1).toArray()
[
 {
 "_id" : ObjectId("5353462f93efef02c962da71"),
 "Type" : "Book",
 "Title" : "Definitive Guide to MongoDB, the",
 "ISBN" : "987-1-4302-3051-9",
 "Publisher" : "Apress",
 "Author" : [
 "Membrey, Peter",
 "Plugge, Eelco",
 "Hawkins, Tim"
 ]
 }
]

4. skip() 跳过前面两条数据。

> db.mediaCollection.find().skip(2).toArray()
[
 {
 "_id" : ObjectId("5353463193efef02c962da73"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind",
 "Tracklist" : [
 {
 "Track" : "1",
 "Title" : "Smells like teen spirit",
 "Length" : "5:02"
 },
 {
 "Track" : "2",
 "Title" : "In Bloom",
 "Length" : "4:15"
 }
 ]
 }
]

5. 组合使用

> db.mediaCollection.find().sort({"Tracklist":1}).toArray()
[
 {
 "_id" : ObjectId("5353462f93efef02c962da71"),
 "Type" : "Book",
 "Title" : "Definitive Guide to MongoDB, the",
 "ISBN" : "987-1-4302-3051-9",
 "Publisher" : "Apress",
 "Author" : [
 "Membrey, Peter",
 "Plugge, Eelco",
 "Hawkins, Tim"
 ]
 },
 {
 "_id" : ObjectId("5353462f93efef02c962da72"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind"
 },
 {
 "_id" : ObjectId("5353463193efef02c962da73"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind",
 "Tracklist" : [
 {
 "Track" : "1",
 "Title" : "Smells like teen spirit",
 "Length" : "5:02"
 },
 {
 "Track" : "2",
 "Title" : "In Bloom",
 "Length" : "4:15"
 }
 ]
 }
]
> db.mediaCollection.find().sort({"Tracklist":1}).limit(1).skip(1).toArray()
[
 {
 "_id" : ObjectId("5353462f93efef02c962da72"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind"
 }
]

6. 自然顺序$natural

> db.mediaCollection.find().sort( { $natural: -1 } ).toArray()
[
 {
 "_id" : ObjectId("5353463193efef02c962da73"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind",
 "Tracklist" : [
 {
 "Track" : "1",
 "Title" : "Smells like teen spirit",
 "Length" : "5:02"
 },
 {
 "Track" : "2",
 "Title" : "In Bloom",
 "Length" : "4:15"
 }
 ]
 },
 {
 "_id" : ObjectId("5353462f93efef02c962da72"),
 "Type" : "CD",
 "Artist" : "Nirvana",
 "Title" : "Nevermind"
 },
 {
 "_id" : ObjectId("5353462f93efef02c962da71"),
 "Type" : "Book",
 "Title" : "Definitive Guide to MongoDB, the",
 "ISBN" : "987-1-4302-3051-9",
 "Publisher" : "Apress",
 "Author" : [
 "Membrey, Peter",
 "Plugge, Eelco",
 "Hawkins, Tim"
 ]
 }
]

原文地址：mongodb sort limit和skip用法, 感谢原作者分享。

mongodbsortlimit和skip用法

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