pymongo方法详解

#########  方法一  ##########
import pymongo
# MongoClient()返回一个mongodb的连接对象client
client = pymongo.MongoClient(host="localhost",port=27017)

#########  方法二  ##########
import pymongo
# MongoClient的第一个参数host还可以直接传MongoDB的连接字符串，以mongodb开头
client = pymongo.MongoClient(host="mongodb://127.0.0.1:27017/")

######  方法一  ######
# 指定test数据库
db = client.test

######  方法二  ######
# 指定test数据库(调用client的test属性即可返回test数据库)
db = client["test"]

######  方法一  ######
# 指定student集合
collection = db.student

######  方法二  ######
# 指定student集合
collection = db["student"]

###### 插入一条数据 ######
student = {
 ‘name‘: ‘Jordan‘,
 ‘age‘: 18,
 ‘gender‘: ‘man‘
}

result = db.collection.insert(student)
# insert()返回执行后文档的主键‘_id‘的值
print(result)  # 5932a68615c2606814c91f3d


######  插入多条数据  ######
student1 = {
 ‘name‘: ‘Jordan‘,
 ‘age‘: 10,
 ‘gender‘: ‘man‘
}

student2 = {
 ‘name‘: ‘Mike‘,
 ‘age‘: 11,
 ‘gender‘: ‘man‘
}

result = collection.insert([student1,student2])
# insert()返回执行后文档的主键‘_id‘的集合
print(result)  #[ObjectId(‘5932a80115c2606a59e8a048‘), ObjectId(‘5932a80115c2606a59e8a049‘)]

student = {
 ‘name‘: ‘Jordan‘,
 ‘age‘: 18,
 ‘gender‘: ‘man‘
}

result = collection.insert_one(student)
# insert_one()返回的是InsertOneResult对象，我们可以调用其inserted_id属性获取_id。
print(result)  # <pymongo.results.InsertOneResult object at 0x10d68b558>
print(result.inserted_id) # 5932ab0f15c2606f0c1cf6c5

student1 = {
 ‘name‘: ‘Jordan‘,
 ‘age‘: 10,
 ‘gender‘: ‘man‘
}

student2 = {
 ‘name‘: ‘Mike‘,
 ‘age‘: 11,
 ‘gender‘: ‘man‘
}

result = collection.insert_many([student1, student2])
# insert_many()方法返回的类型是InsertManyResult，调用inserted_ids属性可以获取插入数据的_id列表
print(result)  # <pymongo.results.InsertManyResult object at 0x101dea558>
print(result.inserted_ids) # [ObjectId(‘5932abf415c2607083d3b2ac‘), ObjectId(‘5932abf415c2607083d3b2ad‘)]

result = db.collection.find_one({"name": "Mike"})
print(result) #{‘_id‘: ObjectId(‘5932a80115c2606a59e8a049‘),‘name‘: ‘Mike‘, ‘age‘: 21, ‘gende‘ :‘man‘}

results = collection.find({"age":18})
print(results) # <pymongo.cursor.Cursor object at 0x1032d5128>
for result in results:
      print(result)
#

# and查询
db.collection.find({ 
         $and :  [
                { "age" :  {$gt : 10 }} , 
                { "gender" :  "man" }
          ]
})

＃or查询
db.collection.find({
          $or : [ 
                    {"age" :  {$gt : 10 }}, 
                    { "gender" :  "man"}
         ]
})

#and查询　和　or查询
db.inventory.find( {
    $and : [
        { $or : [ { price : 0.99 }, { price : 1.99 } ] },
        { $or : [ { sale : true }, { qty : { $lt : 20 } } ] }
    ]
} ) 

count = collection.find().count()
print(count)

#单列升序排列
results = db.collection.find().sort(‘name‘, pymongo.ASCENDING) # 升序(默认)
print([result[‘name‘] for result in results])

#　单列降序排列
results = db.collection.find().sort("name",pymongo.DESCENDING)  #降序
print([result[‘name‘] for result in results])

#多列排序
results = db.collection.find().sort([
  ("name", pymongo.ASCENDING),("age", pymongo.DESCENDING)
])

results = collection.find().sort(‘name‘, pymongo.ASCENDING).skip(2)
print([result[‘name‘] for result in results])

results = collection.find().sort(‘name‘, pymongo.ASCENDING).skip(2).limit(2)
print([result[‘name‘] for result in results])

result = collection.update(
            {"age": {"$lt" : 15}} , 
            {"$set" : {"gender" : "woman"}}
)

print(result)  # {‘ok‘: 1, ‘nModified‘: 1, ‘n‘: 1, ‘updatedExisting‘: True}

result = db.collection.update_one(
              {"name" : "Mike"} , 
              {
                "$inc" : {"age" : 5}, 
                "$set": {"gender": "male"}
              }
)

print(result)   # <pymongo.results.UpdateResult object at 0x10d17b678>

print(result.matched_count, result.modified_count)   # 1  1

result = db.collection.update_many(
              {"name" : "Mike"} , 
              {"$inc" : {"age" : 5}}
)

print(result)   # <pymongo.results.UpdateResult object at 0x10c6384c8>

print(result.matched_count, result.modified_count)   # 3   3

result = db.collection.remove({"age" : {"$gte" : 10}})

print(result)  # {‘ok‘: 3, ‘n‘: 3}

result = collection.delete_one({‘name‘: ‘Kevin‘})
print(result) # <pymongo.results.DeleteResult object at 0x10e6ba4c8>
print(result.deleted_count)  # 1

result = collection.delete_many({‘name‘: ‘Kevin‘})
print(result) # <pymongo.results.DeleteResult object at 0x55e6be5f1>
print(result.deleted_count)  # 4

import pymongo

client = pymongo.MongoClient(host="127.0.0.1", port="27017")

db = client["test"]
coll = db["myindex"]

# 在后台创建唯一索引
coll.create_index([(x,1)], unique = True, background = True,name = "x_1")

# 查看集合coll的所有索引信息
result = coll.index_information()
print(result)

# 在后台创建复合索引
db.myindex.create_index([("x", 1), ("y", 1)])

# 删除索引
coll.drop_index([("x", 1)])
# coll.drop_index("x_1")