Python pyMongoDB 基础使用模版

Python pyMongoDB基础使用 - https://www.cnblogs.com/iAmSoScArEd/p/14903131.html -我超怕的

当不知道MongoDB中有什么数据库时可使用以下函数查询所有数据库：

print(client.database_names()) 

当不知道MongoDB中有什么集合时可使用一下函数获取所有集合

print(db.collection_names()) 

from pymongo.mongo_client import MongoClient
from pymongo import ReadPreference


'''Connect the mongoDB'''
def get_mongo_conn(host, port, user, password, usedatabse):
    db = None
    client = None
    try:
        client = MongoClient(host, port,maxPoolSize=500, connectTimeoutMS=10000,serverSelectionTimeoutMS=5000)
        # print(client.database_names()) 获取所有数据库
        db = client.get_database(usedatabse,read_preference=ReadPreference.SECONDARY)
        
        if db.authenticate(user, password):
            # print('认证成功！')
            # print(db.collection_names()) 获取所有集合
            pass
        else:
            print('认证失败！')
    except Exception as ex:
        print("connection Mongo exception: %s" % ex.message)
    return db, client

# settings
def get_mongo_config():
    return {
        'host' : '127.0.0.1',
        'port' : 27000,
        'dbName' : '1234',
        'userName' : 'username',
        'password' : 'password',
        'collectionName' : 'collection'
    }

# define function to query one row
def query_one(queryDict={}):
    # return dict
    gmc = get_mongo_config()
    host = gmc['host']
    port = gmc['port']
    dbName = gmc['dbName']
    userName = gmc['userName']
    password = gmc['password']
    collectionName = gmc['collectionName']
    db,client = get_mongo_conn(host,port,userName,password,dbName)
    if db is None or client is None:
        print('获取mongo连接失败！')
        return None
    collection = db[collectionName]
    return collection.find_one()

# define function to query more rows
def query_all(queryDict,limit):
    # return list
    gmc = get_mongo_config()
    host = gmc['host']
    port = gmc['port']
    dbName = gmc['dbName']
    userName = gmc['userName']
    password = gmc['password']
    collectionName = gmc['collectionName']
    db,client = get_mongo_conn(host,port,userName,password,dbName)
    if db is None or client is None:
        print('获取mongo连接失败！')
        return None
    collection = db[collectionName]
    return collection.find(queryDict).limit(limit)

def run(device=''):
    queryDict = {} #查询条件
    results = query_all(queryDict,5) # query 5 rows
    for rs in results:
        print(rs)

run()