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MongoDB要如何去查詢數(shù)據(jù)？針對這個問題，這篇文章詳細介紹了相對應(yīng)的分析和解答，希望可以幫助更多想解決這個問題的小伙伴找到更簡單易行的方法。
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1、插入測試數(shù)據(jù)
use flower
db.goods.insert({'goods_name':'Hyacinth',price:10,num:800})
db.goods.insert({goods_name:'Hyacinth',price:10,num:800})
db.goods.insert({goods_name:'violet',price:20,num:1000})
db.goods.insert({goods_name:'Plum blossom',price:20,num:1000})
db.goods.insert({goods_name:'Datura',price:40,num:700})
db.goods.insert({goods_name:'Rosemary',price:39,num:2000})
db.goods.insert({goods_name:'Rosemary',price:39,num:2000,area:{province:'beijing','city':'beijing'}})
db.goods.insert({goods_name:'Rosemary',price:39,num:2000,area:{province:'Shanghai','city':'Shanghai'}})
db.goods.insert({goods_name:'Chinese rose',price:67,num:3700,area:{province:'Henan','city':'Luoyang'}})
db.goods.insert({goods_name:'Chinese rose',price:32,num:900,area:{province:'Henan','city':'Luoyang'}})
db.goods.insert({goods_name:'Chinese rose',price:32,num:900,area:{province:'Henan','city':'Luoyang'},color:
['write','red']})
db.goods.insert({goods_name:'Chinese rose',price:32,num:900,area:{province:'Henan','city':'Luoyang'},color:
['red','green']})
db.goods.insert({goods_name:'Chinese rose',price:32,num:900,area:{province:'Henan','city':'Luoyang'},color:
['write','red','grees']})添加數(shù)據(jù)的方式：普通數(shù)據(jù)的添加、多維數(shù)據(jù)的添加、數(shù)組數(shù)據(jù)的添加
2、MongoDB命令行查詢數(shù)據(jù)
MongoDB命令行查詢數(shù)據(jù)有以下幾種方式：
·籠統(tǒng)方式查詢
·條件限制查詢
·范圍查詢
·多個查詢條件
·多維字段的查詢
·數(shù)組條件的限制查詢
·字段的限制查詢
1）籠統(tǒng)方式查詢：
db.goods.find()
db.goods.find()
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f14b"), "goods_name" : "Hyacinth", "price" : 10, "num" : 800 }
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f14c"), "goods_name" : "Hyacinth", "price" : 10, "num" : 800 }
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f14d"), "goods_name" : "violet", "price" : 20, "num" : 1000 }
……采用這種方式查詢，會查詢所有數(shù)據(jù)。
db.goods.findOne()
查詢所有數(shù)據(jù)中的第一條，并且將數(shù)據(jù)格式化輸出。
db.goods.findOne()
{
"_id" : ObjectId("5cb5bba28a0ad00bec55f14b"),
"goods_name" : "Hyacinth",
"price" : 10,
"num" : 800
}2）條件限制查詢
db.goods.find({goods_name:'Hyacinth'}){ "_id" : ObjectId("5cb5bba28a0ad00bec55f14b"), "goods_name" : "Hyacinth", "price" : 10, "num" : 800 }
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f14c"), "goods_name" : "Hyacinth", "price" : 10, "num" : 800 }相當(dāng)于：SELECT *FROM goods WHERE goods_name='Hyacinth'
db.goods.findOne({goods_name:'Hyacinth'}){
"_id" : ObjectId("5cb5bba28a0ad00bec55f14b"),
"goods_name" : "Hyacinth",
"price" : 10,
"num" : 800
}該_id字段的內(nèi)容值是MongoDB本身算法獲得出來的，_id字段對應(yīng)的值是“全球唯一”的，相當(dāng)于MySQL表里的主鍵id，是唯一的。id可以自行設(shè)置，但是不推薦。
優(yōu)點：方便MongoDB的數(shù)據(jù)做升級、遷移
3）范圍查詢
查詢goods表中價格大于10的數(shù)據(jù)：
db.goods.find({price:{'$gt':10}})查詢goods表中價格大于等于10的數(shù)據(jù)：
db.goods.find({price:{'$gte':10}})查詢goods表中價格小于10的數(shù)據(jù)：
db.goods.find({price:{'$lt':12}})查詢goods表中價格小于等于10的數(shù)據(jù)：
db.goods.find({price:{'$lte':12}})4）多個查詢條件
例如：要求price大于10，庫存大于800
db.goods.find({price:{'$gt':10},num:{'$gt':800}})要求price大于10，庫存為900
db.goods.find({price:{'$gt':10},num:900})5）多維字段的查詢
db.goods.find({'area.province':'Shanghai'})db.goods.find({'area.city':'Shanghai'})6）數(shù)組條件的限制查詢
查詢“color”中有“red”記錄，滿足一個元素即可：
db.goods.find({color:'red'})查詢“color”中有“red”并且(AND)有“write”的記錄：
db.goods.find({color:{'$all':['red','write']}})查詢“price”是10或者(OR)“num”是800
db.goods.find({$or:[{'price':10},{'num':800}]})7）字段的限制查詢
db.goods.find({price:32},{goods_name:1}){ "_id" : ObjectId("5cb5bba28a0ad00bec55f154"), "goods_name" : "Chinese rose" }
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f155"), "goods_name" : "Chinese rose" }
{ "_id" : ObjectId("5cb5bba28a0ad00bec55f156"), "goods_name" : "Chinese rose" }
{ "_id" : ObjectId("5cb5bba48a0ad00bec55f157"), "goods_name" : "Chinese rose" }db.goods.find({price:32},{goods_name:1,_id:0}){ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }db.goods.find({price:{'$gt':30}},{goods_name:1,_id:0}){ "goods_name" : "Datura" }
{ "goods_name" : "Rosemary" }
{ "goods_name" : "Rosemary" }
{ "goods_name" : "Rosemary" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }
{ "goods_name" : "Chinese rose" }db.goods.find({price:{'$gt':30}},{goods_name:1,price:1,_id:0}){ "goods_name" : "Datura", "price" : 40 }
{ "goods_name" : "Rosemary", "price" : 39 }
{ "goods_name" : "Rosemary", "price" : 39 }
{ "goods_name" : "Rosemary", "price" : 39 }
{ "goods_name" : "Chinese rose", "price" : 67 }
{ "goods_name" : "Chinese rose", "price" : 32 }
{ "goods_name" : "Chinese rose", "price" : 32 }
{ "goods_name" : "Chinese rose", "price" : 32 }
{ "goods_name" : "Chinese rose", "price" : 32 }說明：_id字段除外，其它字段可以隨意設(shè)置0，1?？梢栽O(shè)置全部字段都輸出，也設(shè)置為全部字段都不輸出。但是，字段中一個是1，另一個是0，這是不可以。
關(guān)于mongodb要如何去查詢數(shù)據(jù)問題的解答就分享到這里了，希望以上內(nèi)容可以對大家有一定的幫助，如果你還有很多疑惑沒有解開，可以關(guān)注創(chuàng)新互聯(lián)行業(yè)資訊頻道了解更多相關(guān)知識。
文章題目：mongodb要如何去查詢數(shù)據(jù)
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