Python使用PyMongo4.x操作MongoDB的教程分享

pip install pymongo==4.3.3

# 导入模块
from pymongo import *
# 创建客户端对象,使用账号登录
# 方式一：
'''
host：连接的主机名或IP地址，默认为localhost
port：连接使用的端口号，默认为27017
username：用于身份验证的用户名，默认为None
password：用于身份验证的密码，默认为None
authSource：用于身份验证的数据库，默认为None，表示使用admin数据库
'''
client = MongoClient(host="112.74.96.150", port=27017, username="test", password="123456", authSource="demo")
# 方式二：
# url = "mongodb://test:123456@112.74.96.150/demo"
# client = MongoClient(url)
# 断开与MongoDB的连接
client.close()

# 判断数据库是否已存在
dblist = client.list_database_names()
if "demo" in dblist:
  print("demo 数据库已存在！")
# 创建、获取数据库对象
db = client.demo
db = client['demo']
#  判断集合是否存在
collist = db . list_collection_names()
if "user" in collist:  
  print("user 集合已存在！")
# 创建、获取集合
collection = db.user
collection = db["user"]

result = collection.insert_one({"name": "Python", "age": 25})
# 插入操作是否被确认
print(result.acknowledged)  # True
# 插入文档的 _id 字段的值。如果文档没有设置 _id 字段，则 inserted_id 的值为一个新生成的 ObjectId。
print(result.inserted_id)  # 63f569b89a8014989e3b53f6
# 批量插入
result = collection.insert_many([{"name": "Java", "age": 55}, {"name": "Vue", "age": 33}])
# 插入操作是否被确认
print(result.acknowledged)  # True
# 插入的所有文档的 _id 值的列表。
print(result.inserted_ids)  # [ObjectId('63f569b89a8014989e3b53f7'), ObjectId('63f569b89a8014989e3b53f8')]

result = collection.insert_many([{"name": "Java", "age": 55}, {"name": "Vue", "age": 33}])
# 插入操作是否被确认
print(result.acknowledged)  # True
# 插入的所有文档的 _id 值的列表。
print(result.inserted_ids)  # [ObjectId('63f569b89a8014989e3b53f7'), ObjectId('63f569b89a8014989e3b53f8')]

result = collection.find_one({"name": "Python"})
print(result)

rows = collection.find({"name": "Python"})
for row in rows:
    print(row)

rows = collection.find({},{ "_id": 0, "name": 1, "age": 1 }):
for x in 
  print(x)

# 查询年龄大于等于30
query = { "age": { "$gte": 30 } }
result = collection.find(query)
for document in result:
    print(document)

# 查看name 字段中以字母'java'开头的数据
query = { "name": { "$regex": "^java" } }
result = collection.find(query)
for document in result:
    print(document)

result = collection.find().limit(3)
for x in result:
  print(x)

'''
matched_count：符合筛选条件的文档数
modified_count：实际被更新的文档数
upserted_id：如果执行的是 upsert 操作，则包含新插入文档的 _id 值
'''
result = collection.update_one({"name": "Python"}, {"$set": {"age": 25}})
print(result.matched_count)
print(result.modified_count)
print(result.upserted_id)
# 不存在就插入
data = {"name": "Python", "age": 25}
client.test.test.update_one({'name': 'Java'}, {'$set': data}, upsert=True)

collection.update_many({"name": "Python"}, {"$set": {"age": 22}})
# 不存在就插入
data = {"name": "Python", "age": 25}
client.test.test.update_one({'name': 'Java'}, {'$set': data}, upsert=True)

'''
acknowledged：一个布尔值，表示操作是否被确认（即是否执行成功）
deleted_count：一个整数，表示被删除的文档数量
'''
result = collection.delete_one({"name": "Python"})
print(result.acknowledged)
print(result.deleted_count)

collection.delete_many({"age": {"$gt": 20}})

x = user.delete_many({})
print(x.deleted_count, "个文档已删除")
db.user.delete_many({})

# 返回true:删除成功
# 返回false:删除失败(集合不存在)
collection.drop()

result = collection.find().sort("age")
for x in result:
  print(x)

result = collection.find().sort("age", -1)
for x in result:
  print(x)

count = collection.find().count()
query = { "age": { "$gte": 30 } }
count = collection.find(query).count()

# 构建聚合管道
pipeline = [
    {"$group": {"_id": "$category", "total_sales": {"$sum": "$amount"}}},
    {"$sort": {"total_sales": -1}},
    {"$limit": 3}
]
# 执行聚合查询
result = collection.aggregate(pipeline)
for document in result:
    print(document)