python + SQLAlchemy: deleting with the Session object

Question

I can't quite figure this out: I'd like to delete all the records from a table on a matching query. Kind of like this.

engine = sqlalchemy.create_engine(string) meta = MetaData(bind=engine) meta.reflect(bind=engine, schema='myschema')  Base = automap_base(metadata=meta) Base.prepare(engine, reflect=True) Classes = Base.classes  Session = sessionmaker(bind=engine) session = Session()  session.delete(plays.record_id == '123') 

But that isn't working. What's the idea here? Error I get is:

error in parsing record ID 020087: Class 'sqlalchemy.sql.elements.BinaryExpression' is not mapped

Answer 1

In SQL Alchemy you are deleting Objects that you get with a query from the database. This you can do in 2 Ways:

Deleting with query (will issue just one DELETE statement):

session.query(User).filter(User.id==7).delete() session.commit() 

Deleting object instance returned by a query (will issue 2 statements: first SELECT, then DELETE):

obj=session.query(User).filter(User.id==7).first() session.delete(obj) session.commit() 

Answer 2

---

Delete All Records

#for all records session.query(Model).delete() session.commit() 

Deleted Single Row

If you want to delete specific records then try filter clause in the query. ex.

#for specific value session.query(Model).filter(Model.id==123).delete() session.commit() 

Delete Single Record by Object

record_obj = session.query(Model).filter(Model.id==123).first() session.delete(record_obj) session.commit() 

https://flask-sqlalchemy.palletsprojects.com/en/2.x/queries/#deleting-records