sqlalchemy

问题 I have the following code: mytable.to_sql(name='mytable', con=engine, index=True, if_exists='replace') But it keeps throwing the following error: '(1170, "BLOB/TEXT column 'index' used in key specification without a key length")'[SQL: CREATE INDEX ix_mytable_index ON mytable (index)] I think I understand why the error happens but in the context for the code above I don't know how to specify the length. I can't change the underlying database since this code was handed down to me. 来源： https:/

问题 I have the following code: mytable.to_sql(name='mytable', con=engine, index=True, if_exists='replace') But it keeps throwing the following error: '(1170, "BLOB/TEXT column 'index' used in key specification without a key length")'[SQL: CREATE INDEX ix_mytable_index ON mytable (index)] I think I understand why the error happens but in the context for the code above I don't know how to specify the length. I can't change the underlying database since this code was handed down to me. 来源： https:/

问题 I don't think I fully understand association tables. I know how to work with normal tables i.e add rows and what not but I don't understand how to work with an association table. why would I use the below student_identifier = db.Table('student_identifier', db.Column('class_id', db.Integer, db.ForeignKey('classes.class_id')), db.Column('user_id', db.Integer, db.ForeignKey('students.user_id')) ) Vs class studentIdent(db.model): db.Column(db.Integer, db.ForeignKey('classes.class_id')), db.Column

问题 I'm trying to implement a custom mixin in Python 3.6. Child classes would inherit its methods as well as base class. db = flask_sqlalchemy.SQLAlchemy() class CustomMixin(object): # {... __init__ is not being explicitly called, instance and class methods go here ...} class UserModel(CustomMixin, db.Model) # {... class variables, own and inherited methods go here ...} However, although my solution works, it gives a weak warning in PyCharm Community 2019.2: user = UserModel(class_var_1=value_1,

问题 Given a vendor-specific SQLAlchemy datatype, such as sqlalchemy.dialects.postgresql.INTEGER , what is the best way to find the generic SQLAlchemy datatype that best corresponds to this vendor-specific type? For instance, if I have the vendor-specific type sqlalchemy.dialects.postgresql.INTEGER , I would want to map back to sqlalchemy.sql.sqltypes.Integer . I do understand that there might be situations where this isn't possible, for instance if the database supports an esoteric type that

问题 I'm trying to add pagination to my fastapi project. So I decide to use this: fastapi-contrib I follow the same example there, but for some reason I'm getting this error: type object 'MOrdenesTrabajo' has no attribute 'count' Here is my code, thanks for your help!! route @router.get("/ordenes-trabajo") async def read_ot(pagination: Pagination = Depends(), db: Session =Depends(get_db)): filter_kwargs = {} return await pagination.paginate(serializer_class=OtSerializer.MOrdenesTrabajo, **filter

问题 I have a models like this: class User(db.Model): id = db.Column(db.Integer, primary_key=True) first_name = db.Column(db.String(64), index=True) last_name = db.Column(db.String(64), index=True) def full_name(self): return '%s %s' % (self.first_name, self.last_name) I want to get the full_name method in a query, I try it like it: user = db.session.query(User.full_name()).all() But I get this error message: TypeError: full_name() missing 1 required positional argument: 'self' Then I try to call

问题 It was so hard to put that right title. Ok, here it goes. I was following this tutorial to install Apache Airflow on my Mac (Mojave version) - https://towardsdatascience.com/getting-started-with-apache-airflow-df1aa77d7b1b Right at the first step after performing the pip install airflow task, when I run the airflow version command I am getting the following error and then the airflow version appears - ERROR - Failed on pre-execution callback using Traceback (most recent call last): File "

问题 I have a table issue_logs : id | issue_id | from_status | to_status | up_date | remarks ----+----------+-------------+-----------+----------------------------------+----------- 29 | 20 | 10 | 11 | 2018-09-14 11:43:13.907052+05:30 | UPDATED 28 | 20 | 9 | 10 | 2018-09-14 11:42:59.612728+05:30 | UPDATED 27 | 20 | | 9 | 2018-09-11 17:45:35.13891+05:30 | NEW issue 26 | 19 | 9 | 11 | 2018-09-06 16:37:05.935588+05:30 | UPDATED 25 | 19 | | 9 | 2018-09-06 16:27:40.543001+05:30 | NEW issue 24 | 18 | 11

问题 This question already has answers here : SQLAlchemy: how to filter date field? (3 answers) Closed 2 years ago . I want to execute this query in SQLAlchemy SELECT customer_name FROM Orders WHERE order_id = 101 AND order_date BETWEEN '2018-07-01' AND '2018-07-31'; here is my Model: class Orders(db.Model): id = db.Column(db.Integer,primary_key=True) order_id = db.Column(db.Integer,nullable=False) customer_name = db.Column(db.String(100),nullable=False) order_date = db.Column(db.String(100)