FLASK——flask_sqlalchemy db.DateTime 字段保存毫秒/微秒(.000000)

問題描述：

數據庫中時間字段未保存微秒部分。

from app import db
from datetime import datetime


class User(db.Model):
    __tablename__ = 'user'
    userId = db.Column(db.BIGINT, primary_key=True, autoincrement=True, nullable=False)
    userName = db.Column(db.String(16), nullable=False, unique=True)
    passwordHash = db.Column(db.String(16), nullable=False)
    createTime = db.Column(db.DateTime, default=datetime.now, nullable=False)     

nowTime = datetime.now()           # datetime.datetime(2018, 11, 2, 19, 1, 19, 903477)
print nowTime                                             # 2018-11-02 19:03:11.471624
print datetime.strftime(nowTime, '%Y-%m-%d %H:%M:%S.%f')  # 2018-11-02 19:03:11.471624

user = User(
    userName='reidlv',
    passwordHash='this_is_a_passwordHash_string'
    createTime=nowTime
)
db.session.add(user)
db.session.commit()

user_ = User.query.filter_by(userName='reidlv').first()
print user_.createTime.strptime('%Y-%m-%d %H:%M:%S.%f')          # 2018-11-02 19:03:11

解決方法：

db.DateTime 修改爲 DATETIME(fsp=6)

from app import db
from datetime import datetime
from sqlalchemy.dialects.mysql import DATETIME


class User(db.Model):
    __tablename__ = 'user'
    userId = db.Column(db.BIGINT, primary_key=True, autoincrement=True, nullable=False)
    userName = db.Column(db.String(16), nullable=False, unique=True)
    passwordHash = db.Column(db.String(16), nullable=False)
    createTime = db.Column(DATETIME(fsp=6), default=datetime.now, nullable=False)

以上，問題解決。