头歌平台-MongoDB 之滴滴、摩拜都在用的索引
第1关：了解并创建一个简单索引
> use test
switched to db test
> db.student.insert([{_id:1,name:"王小明",age:15,score:90},{_id:2,name:"周晓晓",age:18,score:86},{_id:3,name:"王敏",age:20,score:96},{_id:4,name:"李晓亮",age:15,score:74},{_id:5,name:"张青青",age:21,score:88}])
BulkWriteResult({
"writeErrors" : [ ],
"writeConcernErrors" : [ ],
"nInserted" : 5,
"nUpserted" : 0,
"nMatched" : 0,
"nModified" : 0,
"nRemoved" : 0,
"upserted" : [ ]
})
> db.student.createIndex({score:-1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1
}
第2关：常见索引的创建
编程要求
根据提示，在右侧命令行进行操作，在 test2 数据库中创建集合 article，内容如下：
| _id | title | tags | follwers |
|---|---|---|---|
| 1 | 提升程序员工作效率的6个工具利器 | Alfred，幕布 | 543 |
| 2 | 我是如何从零开始学习前端的 | HTML，Html5，CSS | 1570 |
| 3 | 20个非常有用的JAVA程序片段 | Java，编程 | 1920 |
集合创建完成后，按要求创建以下索引：
-
用字段 follwers 和 title 创建复合升序索引；
-
用字段 tags 创建多 key 降序索引；
-
用
_id创建哈希索引； -
用字段 title 和 tags 创建文本索引。
> use test2
switched to db test2
> db.article.insert([
{_id:1,title:"提升程序员工作效率的6个工具利器",tags:["Alfred","幕布"],follwers:543},
{_id:2,title:"我是如何从零开始学习前端的",tags:["HTML","Html5","CSS"],follwers:1570},
{_id:3,title:"20个非常有用的JAVA程序片段",tags:["Java","编程"],follwers:1920}])
BulkWriteResult({
"writeErrors" : [ ],
"writeConcernErrors" : [ ],
"nInserted" : 3,
"nUpserted" : 0,
"nMatched" : 0,
"nModified" : 0,
"nRemoved" : 0,
"upserted" : [ ]
})
> db.article.createIndex({follwers:1,title:1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1
}
> db.article.createIndex({tags:-1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 2,
"numIndexesAfter" : 3,
"ok" : 1
}
> db.article.createIndex({_id:'hashed'})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 3,
"numIndexesAfter" : 4,
"ok" : 1
}
> db.article.createIndex({title:'text',tags:'text'})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 4,
"numIndexesAfter" : 5,
"ok" : 1
}
第3关：有趣的地理位置索引
编程要求
如图4所示，有6个人 A、B、C、D、E、F 的位置，请将这些位置信息插入到数据库 test3 的集合 people 中，并建立地理位置索引 personloc。
-
查询 A 周围100~3000米有哪些人；
-
查询 B 周围100~5000米有哪些人；
-
查询 C 周围3000~8000米有哪些人；
-
查询 D 周围3000~8000米有哪些人。
-
请逐条插入以下信息和位置 GeoJson 数据：
{_id:1,name:'A',personloc:{type:'Point',coordinates:[116.403981,39.914935]}}{_id:2,name:'B',personloc:{type:'Point',coordinates:[116.433733,39.909511]}}{_id:3,name:'C',personloc:{type:'Point',coordinates:[116.488781,39.949901]}}{_id:4,name:'D',personloc:{type:'Point',coordinates:[116.342609,39.948021]}}{_id:5,name:'E',personloc:{type:'Point',coordinates:[116.328236,39.901098]}}{_id:6,name:'F',personloc:{type:'Point',coordinates:[116.385728,39.871645]}}
echo "
db.people.insert({_id:1,name:'A',personloc:{type:'Point',coordinates:[116.403981,39.914935]}});
db.people.insert({_id:2,name:'B',personloc:{type:'Point',coordinates:[116.433733,39.909511]}});
db.people.insert({_id:3,name:'C',personloc:{type:'Point',coordinates:[116.488781,39.949901]}});
db.people.insert({_id:4,name:'D',personloc:{type:'Point',coordinates:[116.342609,39.948021]}});
db.people.insert({_id:5,name:'E',personloc:{type:'Point',coordinates:[116.328236,39.901098]}});
db.people.insert({_id:6,name:'F',personloc:{type:'Point',coordinates:[116.385728,39.871645]}});
db.people.createIndex({personloc:'2dsphere'});
db.runCommand({geoNear:'people',near:{type:'Point',coordinates:[116.403981,39.914935]},spherical:true,minDistance:100,maxDistance:3000});
db.runCommand({geoNear:'people',near:{type:'Point',coordinates:[116.433733,39.909511]},spherical:true,minDistance:100,maxDistance:5000});
db.runCommand({geoNear:'people',near:{type:'Point',coordinates:[116.488781,39.949901]},spherical:true,minDistance:3000,maxDistance:8000});
db.runCommand({geoNear:'people',near:{type:'Point',coordinates:[116.342609,39.948021]},spherical:true,minDistance:3000,maxDistance:8000});
"