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srcmini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.srcmini.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。如果你未指定排序首选项, 它将以升序显示文档。