MongoDB教育訓練-03

 

 

count 儘量不要用

db.inspections.countDocuments() #精確查詢(1)

db.inspections.count() #

insertOne 插入一筆資料

#插入一條資料
insertOne 

id 本身會包含時間

getTimestamp #取得時間

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insertMany 插入多筆資料

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有序插入＆無序插入

{ordered: true | false}

• 有序可保證順序，速度較慢，中間錯誤會全部返回
• 使用無序不影響，中間錯誤紀錄

 

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搜尋

• find()
• findOne()

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返回特定欄位

 

Find 搜尋20筆資料

for(var i = 0; i < 200; i++) db.taxis.insertOne({plate: i})

# plate = 5 
db.taxis.find({plate:5})

# plate >= 5 
db.taxis.find({plate:{$gt: 5}})

#下20筆
it 

 

curosr 10分鐘會被丟棄

db.diaries.drop()

db.diaries.insertMany([
{ name: "dug", day: ISODate("2014-11-04"), txt: "went for a walk"},
{ name: "dug", day: ISODate("2014-11-06"), txt: "saw a squirrel"},
{ name: "ray", day: ISODate("2014-11-06"), txt: "met dug in the park"},
{ name: "dug", day: ISODate("2014-11-09"), txt: "got a treat"}
])

#找出 name = dug

#輸出 name, text

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子查詢

# city = "New York" 即可
address.city :"New York"
#{ city:"New York"} 完整匹配
address : { city:"New York"}} 

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範圍查詢

 

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Boolen 查詢

$or : [ {species:"cat", color:"black"},
		{species:"dog", color:"brown"}}]
#等於

where (species = "cat" and color = "black") or (species = "dog" and color = "brown")

db.grades.find({ student_id : {$lt: 65}})

db.inspections.find({$or :[ {result:"Pass"},{result:"Fail"}]})