ORM Model Tokens has a field that is the creation time, as follows: create_time = db.Column(db.DateTime, nullable=False, default=datetime.now) Screenshot in the database: stackoverflowcast: db.cast(t.create_time, db.DATE)print: alone prin...

as shown in the figure below, does SQLAlchemy have a simple way to directly declare that the specified field is not mapped serialized? for example, does java s Hibernate framework have such a function? (although there are other "indirect " solut...

according to the book, this error will be reported all the time, which probably means that this error can only be used in the same thread, right? Do you want to use creat_scoped_session? please give me some advice. Thank you! sqlalchemy.exc.Programm...

the result of the query is a model.user type, not a simple dict, so how can you use it like an object? user = User.query.filter(User.username == username, User.password == password).first() ...

now there is a problem in the project. The project is completed in flask. Now there are several data tables with the same order field, and all need to query the data of these tables and adjust the value of the order field. the inefficient way is to im...

engine = create_engine ( "mysql+pymysql: root:111@localhost xxx ", encoding= utf-8 , echo=True) Session_class = sessionmaker (bind=engine) Session = Session_class () modify a record user = Session.query (User). Filter_by (id=1). First () user.n...

recently, it often appears when using sqlalchemy+python+gunicorn to develop a small project. Sqlalchemy reads the data and returns None, but it is possible to view the data in the database. As a novice, I suspect that there is something wrong with my wr...

the results queried with sqlalchemy contain other entity class objects and are stored in the sqlalchemy-related container. How to convert to json? ...

suppose there is a table A whose fields are roughly as follows: < table > < thead > < tr > < th > column < th > < th > index < th > < tr > < thead > < tbody > < tr > < td > id < td > < td > True < td > < tr > < tr > < td > name < td > <...

import asyncio import sqlalchemy as sa from aiomysql.sa import create_engine @asyncio.coroutine def go(): engine = yield from create_engine(user= root ,db= test ,host= 127.0.0.1 ,password= root ) metadata = sa.MetaData(bind=engine) ...

I recently learned Flask s SQLAlchemy,. Suppose I have such a map information table. Map has fields a, b is shaping. I want to query the data of an and b in a specific range, such as result_query = Map.query.filter (1 ...

suddenly there is an idea that if the field changes are complicated when making a query, you can t write the query statement, just like A.query.filter (name== ds ) is written dead. If I need to dynamically switch query fields, especially when there ...

A model has data A1 B model has data b1 b1.key1 is a foreign key, associated with the primary key of a1.id is there a problem for me to delete A1 data directly now? db.session.delete (A1) db.session.commit () ...

for example, I like % R% answer, the query results include not only R, but also r, which is not what I want, I want to be case-sensitive. I guess it has something to do with the proofreading rules of the table. My table uses utf8mb4 encoding, and the pr...

these are the data of my two tables: flask: sqlalchemy: : ...

The database is mysql, checked the document and found no exclude, only an except_. if my table is called table_a, and has a status field, if it is a single field, you can use! = to exclude, what should I say if it is a scope? For example, if you have ...

Database table mytable structure id id_card INT VARCHAR (32) where id is the self-increasing primary key how to gracefully implement if id_card insertion when it does not exist, of course, thread-safe can not be repeated. my implementation is to a...

see examples that define the model directly at the start of the program, such as _ _ init__.py, server.py. my idea is to define the model in the corresponding .py file and create it directly when needed. I don t know how to organize the project file a...

1.sqlalchemy query data, sort according to the data in the field (Chinese) to Pinyin (ascending order) 2. It is known that there are func.convert and sql.func.CONVERT methods in sqlalchemy, and the import method is . from sqlalchemy import func from sq...

problem description I want to execute the SQL script directly to initialize the database when initializing the flask application. the database is Postgresql. the environmental background of the problems and what methods you have tried flask tutor...