I have 2 table like this: Then I try to making 2 kinds of query to get data for the relationship models. first, I make it like this: and the second one I use join statement on that: My questions are, what’s the difference in that query while in the second one I use the join statement but the result
Tag: sqlalchemy
How to implement a search function using a raw SQL query
I am creating an app guided by CS50’s web series, which requires me to ONLY use raw SQL queries not ORM. I am trying to make a search function where a user can look up the list of books that’s …
SQLAlchemy – Return filtered table AND corresponding foreign table values
I have the following SQLAlchemy mapped classes: class ShowModel(db.Model): __tablename__ = ‘shows’ id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(100)) …
How to verify SqlAlchemy engine object
I can declare engine object with the invalid username, password or address and get no exception or error: it prints likes it is a valid engine object: What would be a common way to verify (to check) if the engine object is valid or if it is “connectable” to db? Answer Question: How to verify if the engine object is
How to perform a left join in SQLALchemy?
I have a SQL query which perfroms a series of left joins on a few tables: So far, I have: but I can’t figure out how to make the join a LEFT JOIN. Answer The isouter=True flag will produce a LEFT OUTER JOIN which is the same as a LEFT JOIN. With your code: Declarative example:
How to do a where exists in nested query with SQLAlchemy?
I’m trying to do a WHERE EXISTS clause in SQLAlchemy. The SQL looks like this: Is it possible to do this in SQLAlchemy without using raw SQL? I’ve tried this but it doesn’t seem to be returning the correct results: Answer Use sqlalchemy.orm.aliased() and exists():
SQLAlchemy substring is in string
I am trying to query a database for records that have a string field inside an input search string. Something like this: Of course that does not work since it is not a valid SQLAlchemy statement. This seems a simple problem but I really can’t find the right column operator. I tried the in_ operator: But that of course is
Postgresql ON CONFLICT in sqlalchemy
I’ve read quite a few resources (ao. 1, 2) but I’m unable to get Postgresql’s ON CONFLICT IGNORE behaviour working in sqlalchemy. I’ve used this accepted answer as a basis, but it gives I’ve tried adding the postgresql dialect to the @compile clause, renaming my object, but it doesn’t work. I also tried to use the str(insert())+ ” ON CONFILCT
Querying association table object directly
I have to query the relationships directly, since I have to display them seperatly. task_user = db.Table( ‘pimpy_task_user’, db.Column(‘task_id’, db.Integer, db.ForeignKey(‘pimpy_task.id’)), …
Why isn’t SQLAlchemy creating serial columns?
SQLAlchemy is generating, but not enabling, sequences for columns in postgresql. I suspect I may be doing something wrong in engine setup. Using an example from the SQLAlchemy tutorial (http://docs.sqlalchemy.org/en/rel_0_9/orm/tutorial.html): With this script, the following table is generated: However, a sequence was created: SQLAlchemy 0.9.1, Python 2.7.5+, Postgresql 9.3.1, Ubuntu 13.10 -Reece Answer this is because you provided it with