#1、使用PyMongo
import pymongo


#2、连接MongoDB

client = pymongo.MongoClient(host='localhost', port=27017)
client2 = pymongo.MongoClient('mongodb://localhost:27017/')


#3、指定数据库(tera)
db = client.tera
db2 = client2['tera']


#4、指定集合
collection = db.tera
collection2 = db['tera']


#5、插入数据
"""
#1）insert_one()会返回InsertOneResult对象，可以调用inserted_id属性，获得_id
people = {'name': 'wzw', 'age': 25,'hobby': 'code'}
result = collection2.insert_one(people)
print(result.inserted_id)
print(result)


#2）插入多条insert_many()方法；注意：通过insert_one插入后，不能再次使用insert_many()插入，对象_id会重复，导致插入报错
people2 = {'name': 'wzw2', 'age': 25,'hobby': 'code'}
people3 = {'name': 'wzw3', 'age': 25,'hobby': 'code'}
result = collection.insert_many([people2, people3])
print(result)
print(result.inserted_ids)
"""




#6、查询
#1)普通查询
result = collection.find_one({'name': 'wzw'})
print(result)
#2）通过_id来查询，需要构建objectid对象，使用bson库
from bson.objectid import ObjectId
result = collection.find_one({'_id':ObjectId('64eca04b9c52deab56c077ec')})
print(result)
#3)查询多条数据
result = collection.find({'age': 25})
print(result)   #result 结果集，是一个生成器对象
for i in result:
    print(i)


#7、计数
#错误：count = collection.find().count()  #未成功，因为collection.find()结果集是一个Cursor，没有count()的方法
#1)方法1
result = collection.find()
count = len(list(result))
print(count)
#2）方法2
count = collection.count_documents({})
print(count)



#8、排序
print('升序')
results = collection.find().sort('name', pymongo.ASCENDING)
#结果集cursor，输出name字段排序
print([result['name'] for result in results])

print('降序')
results = collection.find().sort('name', pymongo.DESCENDING)
print([result['name'] for result in results])



#9、更新
print('==============更新')
condition = {'name': 'wzw'}
people = collection.find_one(condition)
print(people)
#更新age为28 
update = {'$set': {'age': 28}}    #update = {'$inc': {'age': 1}}  age+1

#更新第一条匹配到的值
#result = collection.update_one(condition, update)

#更新所有匹配到的值
result = collection.update_many(condition, update)

print(collection.find_one(condition))
#匹配条数、更新条数
print(result.matched_count,result.modified_count)


#10、删除
print('==========================删除')
result = collection.delete_one({'name': 'wzw1'})
result = collection.delete_many({'name': 'wzw'})
print(result,result.deleted_count)

res = collection.find()
for i in res:
    print(i)