MongoDB数据库更新和删除文档

<span style="font-size:14px;">name：创建的集合名称
options：是一个作为初始化的文档(可选)</span>

<span style="font-size:14px;">> db.createCollection("jingdong")            #无参数
{ "ok" : 1 }
> show collections
jingdong
system.indexes
> db.createCollection("jingdong", { capped : 1, autoIndexID : 1, size : 6142800, max : 10000 } )            #带参数
{ "ok ": 1 }</span>

删除集合 

db.COLLECTION.drop()

<span style="font-size:14px;">> use JD
switched to db JD
> show collections
jingdong
jingdong1
system.indexes
> db.jingdong.drop()
ture
> show collections
jingdong1
system.indexes</span>

</pre><pre name="code" class="python"><span style="font-size:14px;">> userdoc1=({"user_id":1,"name":"cloud","state":"active","actor":"user","e-mail":" test@qq.com","VM_num":2,"time":[{"date":"2014-08-12","hour":"10:53 PM"}] })        
> userdoc2=({"user_id":2,"name":"testadmin","state":"active","actor":"admin","e-mail":" test@qq.com","VM_num":2,"time":[{"date":"2014-08-11","hour":"06:34 AM"}] })    
> doc=({"name":"peter","position":"teacher"})        #先定义文档
> use JD
switched to db JD
> db.jingdong.insert(userdoc1)
WriteResult({"nInserted":1})
> db.jingdong.insert(userdoc2)
WriteResult({"nInserted":1})
> db.jingdong.insert(doc1)
WriteResult({"nInserted":1})</span>

更新文档

 db.COLLECTION_NAME.update(SELECTION_CRITERIA,UPDATED_DATA)

<span style="font-size:14px;">#将user_id=2的文档的e-mail改为group@qq.com         
> db.jingdong.update({"user_id":"02","e-mail":"test@qq.com"},{$set:{"e-mail":"group@qq.com"}})
#第一个大括号内容标示查找条件，第二个大括号内容则表示更新后的数据
WriteResult({"nMatched":1,"nUpserted":1,"nModified":1})
> db.jingdong.find()</span>

<pre name="code" class="python"><span style="font-size:14px;">默认的update函数只对一个文档更新，如果想作用所有文档，则需要加入multi:ture</span>

<span style="font-size:14px;">db.shiyanlou.update({"e-mail":"test@qq.com"},{$set:{"e-mail":"group@qq.com"}},{multi:ture})</span>

替换已存在的文档 

db.COLLECTION_NAME.save({_id:ObjectId(),NEW_DATA})

<span style="font-size:14px;">> db.shiyanlou.save({"_id":ObjectId("53ea174ccb4c62646d9544f4","name":"Bob","position":"techer")})
WriteResult({"nMatched":1,"nUpserted":1,"nModified":1})</span>

删除文档 

db.COLLECTION_NAME.remove(DELECTION_CRITERIA)

<span style="font-size:14px;">> db.shiyanlou.remove({"name":"Bob"})
WriteResult({"nRemoved":1})</span>

createCollection()：创建集合

db.COLLECTION.drop()：删除集合

db.COLLECTION_NAME.insert(document)：插入文档

db.COLLECTION_NAME.update(SELECTION_CRITERIA,UPDATED_DATA)：更新文档

db.COLLECTION_NAME.save({_id:ObjectId(),NEW_DATA})：替换已存在的文档

db.COLLECTION_NAME.remove(DELECTION_CRITERIA)：删除文档