Python Flask:在插入数据库时无法调用获取“operational error”对象

Question

我正在尝试创建一个python flask脚本，它将向数据库中添加一行。我的代码是：

main.py：

import json
import sys
from flask import Flask, request
from app.config import DB
from app.items.items import ItemsAPI
from app.users.accounts import AccountsAPI
from app.users.customers import CustomersAPI

app = Flask(__name__)
db = DB()

app.register_blueprint(ItemsAPI)
app.register_blueprint(CustomersAPI)
app.register_blueprint(AccountsAPI)

@app.route('/home')
def hello_world():
    return "Welcome to Omnimoda."

@app.route('/dbtest', methods=['GET'])
def hello_database():
    q_sql = "SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = %s"
    a_sql = ("omnimoda",)
    test_request = db.query(q_sql, a_sql)
    result_request = test_request.fetchall()
    if (result_request is None):
        return "Database does not exist."
    else:
        return "Database exists."

if __name__ == '__main__':
    app.run(host = '0.0.0.0', debug=True)

customers.py：

^{pr2}$

最后，我的config.py：

from flask import Flask
import MySQLdb

class DB:
    conn = None

    def connect(self):
        self.conn = MySQLdb.connect(host="localhost", user="lance", passwd="lance", db="omnimoda")
        self.conn.autocommit(True)

    def query(self, sql, values):
        try:
            print values
            self.connect()
            cursor = self.conn.cursor()
            cursor.execute(sql, values)
            return cursor
        except Exception, e:
            return e

    def commit_ret_lastrow(self, sql, values):
        try:
            self.connect()
            cursor = self.conn.cursor()
            cursor.execute(sql, values)
            return cursor.lastrowid
        except Exception, e:
            return e

不幸的是，在CocoaRestClient中测试它时，通过http://127.0.0.1:5000/customers/addtest：

我得到以下无用的错误：

127.0.0.1 - - [30/Jun/2015 22:04:22] "POST /customers/addtest HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1478, in full_dispatch_request
    response = self.make_response(rv)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1577, in make_response
    rv = self.response_class.force_type(rv, request.environ)
  File "/Library/Python/2.7/site-packages/werkzeug/wrappers.py", line 841, in force_type
    response = BaseResponse(*_run_wsgi_app(response, environ))
  File "/Library/Python/2.7/site-packages/werkzeug/test.py", line 867, in run_wsgi_app
    app_iter = app(environ, start_response)
TypeError: 'OperationalError' object is not callable

我不知道怎么了。我能帮个忙吗？在

Answer 1

查询和commit\u ret_lastrow方法的最后两行没有任何意义。如果有异常，你捕捉它，然后返回它。所以Flask试图把它当作你的实际应用，显然它做不到。在

放下那些台词，然后尝试/完全排除。无论如何，您不应该捕获所有异常；如果您确定，您可以捕获特定的数据库异常—例如IntegrityError—但通常只应捕获您知道可以处理的异常。否则，只需让异常出现，框架就可以记录或显示它。在