Question

我创建了一个包含dateTime和timezone列的表。在我的 model.py ：

中

db = SQLAlchemy(app)

class Messages(db.Model):
    __tablename__ = 'messages'
    msgId = db.Column('msg_id', db.Integer, primary_key=True)
    fullName = db.Column(db.String(60))
    message = db.Column(db.String)
    email = db.Column(db.String, unique=True)
    visitorId = db.Column(db.String(10))
    done = db.Column(db.Boolean)
    pub_date = db.Column(types.Time(timezone=True)) 

    def __init__(self, fullName, email, message, visitorId, submitTime):
        self.fullName = fullName
        self.email = email
        self.message = message
        self.visitorId = visitorId
        self.done = False
        self.pub_date = submitTime

我使用db.create_all()上的heroku pg:psql创建了表格，结果如下：

DATABASE=> \d messages
                                    Table "public.messages"
  Column   |         Type          |                         Modifiers                         
-----------+-----------------------+-----------------------------------------------------------
 msg_id    | integer               | not null default nextval('messages_msg_id_seq'::regclass)
 fullName  | character varying(60) | 
 message   | character varying     | 
 email     | character varying     | 
 visitorId | character varying(10) | 
 done      | boolean               | 
 pub_date  | time with time zone   |

无论我使用时区的时区/日期时间似乎都被打+00，这是UTC。

4 | ciasto       | testing    |          | 9IQVW1K6W | f    | 15:48:31.784704+00

为什么会这样？

我正在使用下面的路由函数来传递时间，该函数应该从下面传递正确的dtWithZone到postgreSQL的表消息pub_date

@app.route('/newmsg', methods=['GET', 'POST'])
def newmsg():
    form = _appforms.MessagingForm()
    if form.validate_on_submit():
        name = request.form['fullName']
        ip = request.access_route[0] # gives ip address of the visitor
        unique_visitor_id = request.cookies.get("unique_visitor")

        data = _utils.getJsonFromURL("http://ip-api.com/json/{}".format(ip))
        tz = "Asia/Kolkata"
        if data["status"] == "success":
            tz = data["timezone"]

        flash("Your IP is {} and you are visiting this site from {} timezone.".format(ip, tz))

        dtWithZone = datetime.datetime.now(pytz.timezone(tz))
        msg = Messages(name, request.form['email'], request.form['message'], unique_visitor_id, dtWithZone)
        _db.session.add(msg)
        _db.session.commit()
        msg = "Thank you, {}".format(name)
        return render_template('thankyou.html', form=form, msg=msg)
    return render_template('newMessage.html', form=form, title=" | Messaging", msg="Write your message")

然而，这在我的本地计算机上正常工作并查看表格条目我可以看到：

  8 | tester | local teasing   |         | NV33A1L66 | f  | 21:09:24.804903+05:30

Answer 1

弄清楚自己 , since PostgreSQL timezone aware, if we punch datetime with timezone it converts it to PostgreSQL local timezone , so on heroku it is set to UTC so it was always getting converted to UTC format, so I converted the column pub_date to db.String(24) and saving date/time/ with timezone as string. which works perfect.

更新了消息：

首先定义具有接受带有时区的日期时间的列的表：

<强>的src / model.py

pub_date

然后从python终端：运行db.String(24) 这将在postgresql中创建具有适当列类型/名称的表。然后有一个下面的函数连接到postgresSQL与用户时区：

from sqlalchemy import MetaData
from sqlalchemy import create_engine
from sqlalchemy import DateTime

db = SQLAlchemy(app)

class Messages(db.Model):
    __tablename__ = 'messages'
    msgId = db.Column('msg_id', db.Integer, primary_key=True)
    fullName = db.Column(db.String(60))
    message = db.Column(db.String)
    email = db.Column(db.String, unique=True)
    visitorId = db.Column(db.String(10))
    done = db.Column(db.Boolean)
    pub_date = db.Column(DateTime(timezone=True))

就是这样！

现在从路由功能我做了以下更改：

from src.model import db; db.create_all()

完美（y）

Answer 2

所以这是一个关于你的时区的简短教程。要查看postgresql在其内部tz数据库中有哪些时区，请运行以下查询：

select * from pg_timezone_names ;
(edited list)
               name               | abbrev | utc_offset | is_dst
----------------------------------+--------+------------+--------
 America/Denver                   | MDT    | -06:00:00  | t
 America/Phoenix                  | MST    | -07:00:00  | f
 America/New_York                 | EDT    | -04:00:00  | t
 America/Chicago                  | CDT    | -05:00:00  | t
 America/Los_Angeles              | PDT    | -07:00:00  | t

以下是设置tz和插入时间戳的示例：

create table tztest (ts timestamptz, tz text);
set timezone="America/New_York";
insert into tztest values ('2017-01-10 12:00:00','America/New_York');
set timezone='America/Chicago';
insert into tztest values ('2017-01-10 12:00:00','America/Chicago');
set timezone='America/Denver';
insert into tztest values ('2017-01-10 12:00:00','America/Denver');
set timezone='America/Phoenix';
insert into tztest values ('2017-01-10 12:00:00','America/Phoenix');
set timezone='America/Los_Angeles';
insert into tztest values ('2017-01-10 12:00:00','America/Los_Angeles')
select * from tztest ;
           ts           |         tz
------------------------+---------------------
 2017-01-10 09:00:00-08 | America/New_York
 2017-01-10 10:00:00-08 | America/Chicago
 2017-01-10 11:00:00-08 | America/Denver
 2017-01-10 11:00:00-08 | America/Phoenix
 2017-01-10 12:00:00-08 | America/Los_Angeles

请注意，虽然洛杉矶被列为-07：00：00抵消，但不是夏天，所以现在是1月1日的-08：00：00。

要查看实际存储的时间戳，请将时区设置为UTC：

set timezone='UTC';
select * from tztest ;
           ts           |         tz
------------------------+---------------------
 2017-01-10 17:00:00+00 | America/New_York
 2017-01-10 18:00:00+00 | America/Chicago
 2017-01-10 19:00:00+00 | America/Denver
 2017-01-10 19:00:00+00 | America/Phoenix
 2017-01-10 20:00:00+00 | America/Los_Angeles

不正确的时区被打入数据库

2 个答案: