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📜  MongoDB sort()

📅  最后修改于: 2020-11-23 00:57:30             🧑  作者: Mango

MongoDB sort()方法

在MongoDB中，sort()方法用于对集合中的文档进行排序。此方法接受包含字段列表及其排序顺序的文档。

排序顺序指定为1或-1。

  • 1用于升序排序。
  • -1用于降序排序。

句法：

db.COLLECTION_NAME.find().sort({KEY:1})

情境

考虑一个具有集合名称javatpoint的示例。

该集合中包含以下字段。

    [
      {
        Course: "Java",
        details: { Duration: "6 months", Trainer: "Sonoo Jaiswal" },
        Batch: [ { size: "Medium", qty: 25 } ],
        category: "Programming Language"
      },
      {
        Course: ".Net",
        details: { Duration: "6 months", Trainer: "Prashant Verma" },
        Batch: [ { size: "Small", qty: 5 }, { size: "Medium", qty: 10 }, ],
        category: "Programming Language"
      },
      {
        Course: "Web Designing",
        details: { Duration: "3 months", Trainer: "Rashmi Desai" },
        Batch: [ { size: "Small", qty: 5 }, { size: "Large", qty: 10 } ],
        category: "Programming Language"
      }
    ];

执行以下查询以按降序显示文档。

db.javatpoint.find().sort({"Course":-1})

这将按降序显示文档。

{ "_id" : ObjectId("564dbced8e2c097d15fbb603"), "Course" : "Web Designing", "det
ails" : { "Duration" : "3 months", "Trainer" : "Rashmi Desai" }, "Batch" : [ { "
size" : "Small", "qty" : 5 }, { "size" : "Large", "qty" : 10 } ], "category" : "
Programming Language" }
{ "_id" : ObjectId("564dbced8e2c097d15fbb601"), "Course" : "Java", "details" : {
 "Duration" : "6 months", "Trainer" : "Sonoo Jaiswal" }, "Batch" : [ { "size" :
"Medium", "qty" : 25 } ], "category" : "Programming Language" }
{ "_id" : ObjectId("564dbced8e2c097d15fbb602"), "Course" : ".Net", "details" : {
 "Duration" : "6 months", "Trainer" : "Prashant Verma" }, "Batch" : [ { "size" :
 "Small", "qty" : 5 }, { "size" : "Medium", "qty" : 10 } ], "category" : "Progra
mming Language" }

注意：默认情况下，sort()方法以升序显示文档。如果未指定排序首选项，它将以升序显示文档。