mysql - python开发web service 中数据库链接和释放应该怎么处理？

Question

用tornado开发web service服务。服务端根据接收到的json数据对mysql数据库进行查询，并把结果反馈给用户。采用sqlalchemy对数据库进行操作，以下对数据库链接的创建，释放是否合理呢？

class db:

    def __init__(self,db_ip='',db_name='',db_user='',db_pass='',db_charset=''):
        self.db_str = 'mysql+pymysql://'+db_user+':'+db_pass+'@'+db_ip+':3306/'+db_name+'?'+'charset='+db_charset
        self.engine = create_engine(self.db_str, encoding='utf-8', echo=False)
        self.dbsession = sessionmaker(bind=self.engine)
        
    def return_dbsession(self):
        return self.dbsession
        
    def close_session(self):
        self.session.close()

database = db(db_ip='127.0.0.1', db_name='data_utf', db_user='root', db_pass='root', db_charset='utf8')

处理post请求代码如下

class rcvRequest(tornado.web.Request):
    session = scoped_session(database.return_dbsession())()
    response = []
    for ctt in session.query(table).filter(table.ID == id):
        response.append(ctt)
    self.write(str(response))
    session.close()

Answer 1

不合理,每來一次請求就建立一次連接不是很浪費嗎?
sqlalchemy可以很好的幫你管理連接池,找找資料,用連接池吧.

Answer 2

程式碼調整為以下這種方式是否合理？

def db(db_ip='',db_name='',db_user='',db_pass='',db_charset=''):
        db_str = 'mysql+pymysql://'+db_user+':'+db_pass+'@'+db_ip+':3306/'+db_name+'?'+'charset='+db_charset
        engine = create_engine(self.db_str, encoding='utf-8', echo=False)
        dbsession = sessionmaker(bind=self.engine)
        return dbsession

database =db(db_ip='127.0.0.1', db_name='data_utf', db_user='root', db_pass='root', db_charset='utf8')
        
class rcvRequest(tornado.web.Request):

    def initialize(self):
        self.session = scoped_session(database)()
        
    @tornado.gen.coroutine
    def post(self):
        response = []
        for ctt in self.session.query(table).filter(table.ID == id):
            response.append(ctt)
        self.write(str(response))
    
    def on_finish(self):
        self.session.close()

Answer 3

還是建議找個ORM吧。你這樣一個連結就要求一次搞不好數據服務就掛掉了。

Answer 4

請參考
https://github.com/PyMySQL/To...