sqlalchemy

How do I specify a null relation in SQLAlchemy?

Not sure what the correct title for this question should be. I have the following schema: Matters have a one-many relationship to WorkItems. WorkItems have a one-one (or one-zero) relationship to LineItems. I am trying to create the following relation between Matters and WorkItems Matter.unbilled_work_items = orm.relation(WorkItem, ...

How to save to two tables using one SQLAlchemy model

I have an SQLAlchemy ORM class, linked to MySQL, which works great at saving the data I need down to the underlying table. However, I would like to also save the identical data to a second archive table. Here's some psudocode to try and explain what I mean my_data = Data() #An ORM Class my_data.name = "foo" #This saves just to the 'da...

SqlAlchemy hangs after adding record in MS SQL

I'm running SQLAlchemy on Jython and trying to connect to a MS SQL database using jTDS with windows authentication. I can query and delete just fine but when I try to insert new values it will hang when I commit. print 'before add' session.add(newVal) print 'after add' session.commit() print 'after commit' I see the first two print s...

How to use SQLAlchemy to dump an SQL file from query expressions to bulk-insert into a DBMS?

Please bear with me as I explain the problem, how I tried to solve it, and my question on how to improve it is at the end. I have a 100,000 line csv file from an offline batch job and I needed to insert it into the database as its proper models. Ordinarily, if this is a fairly straight-forward load, this can be trivially loaded by just ...

Faster Insertion of Records into a Table with SQLAlchemy

I am parsing a log and inserting it into either MySQL or SQLite using SQLAlchemy and Python. Right now I open a connection to the DB, and as I loop over each line, I insert it after it is parsed (This is just one big table right now, not very experienced with SQL). I then close the connection when the loop is done. The summarized code ...

What is the best way pre filter user access for sqlalchemy queries?

I have been looking at the sqlalchemy recipes on their wiki, but don't know which one is best to implement what I am trying to do. Every row on in my tables have an user_id associated with it. Right now, for every query, I queried by the id of the user that's currently logged in, then query by the criteria I am interested in. My conce...

How to generate graphs and statistics from SQLAlchemy tables [Python]?

Hi all, After running a bunch of simulations I'm going to be outputting the results into a table created using SQLAlchemy. I plan to use this data to generatw statistics - mean and variance being key. These, in turn, will be used to generate some graphs - histograms/line graphs, pie-charts and box-and-whisker plots specifically. I'm aw...

Hooking entity creation in SQLAlchemy

I want to write a SessionExtension that fires a 'Foo-created' event or 'Bar-created' event every time a new Foo or new Bar is committed to the database. However, once inside the after_commit method, I don't know where to find which entities have been committed. Where do I get this information? ...

how do simple SQLAlchemy relationships work?

I'm no database expert -- I just know the basics, really. I've picked up SQLAlchemy for a small project, and I'm using the declarative base configuration rather than the "normal" way. This way seems a lot simpler. However, while setting up my database schema, I realized I don't understand some database relationship concepts. If I had a...

Use a foreign key mapping to get data from the other table using Python and SQLAlchemy.

Hmm, the title was harder to formulate than I thought. Basically, I've got these simple classes mapped to tables, using SQLAlchemy. I know they're missing a few items but those aren't essential for highlighting the problem. class Customer(object): def __init__(self, uid, name, email): self.uid = uid self.name = name...

Setting attributes of a class during construction from **kwargs

Python noob here, Currently I'm working with SQLAlchemy, and I have this: from __init__ import Base from sqlalchemy.schema import Column, ForeignKey from sqlalchemy.types import Integer, String from sqlalchemy.orm import relationship class User(Base): __tablename__ = "users" id = Column(Integer, primary_key=True) username ...

Filter objects within two seconds of one another using SQLAlchemy

Hello: I have two tables with a column 'date'. One holds (name, date) and the other holds (date, p1, p2). Given a name, I want to use the date in table 1 to query p1 and p2 from table two; the match should happen if date in table one is within two seconds of date in table two. How can you accomplish this using SQLAlchemy? I've tried (u...

SQL Alchemy MVC and cross controller joins

When using SQL Alchemy for abstracting your data access layer and using controllers as the way to access objects from that abstraction layer, how should joins be handled? So for example, say you have an Orders controller class that manages Order objects such that it provides getOrder, saveOrder, etc methods and likewise a similar contro...

SQLAlchemy - relationship limited on more than just the foreign key

I have a wiki db layout with Page and Revisions. Each Revision has a page_id referencing the Page, a page relationship to the referenced page; each Page has a all_revisions relationship to all its revisions. So far so common. But I want to implement different epochs for the pages: If a page was deleted and is recreated, the new revision...

Set AUTO_INCREMENT using SqlAlchemy with MySQL on Columns with non-primary keys?

I can't figure out how to set AUTO_INCREMENT on a UNIQUE column using SqlAlchemy 0.6.0 with MySQL 5. I know this can be done in MySQL, but I don't want to have to distribute extra .sql scripts in order to set up the databases for my application. I want SqlAlchemy to build the schema from within Python. As far as I have found so far, th...

Transitioning from php to python/pylons/SQLAlchemy -- Are ORMs the standard now?

Should I invest a lot of time trying to figure out an ORM style implementation, or is it still common to just stick with standard SQL queries in python/pylons/sqlalchemy? ...

Debugging (displaying) SQL command sent to the db by SQLAlchemy

I have an ORM class called Person, which wraps around a person table: After setting up the connection to the db etc, I run the ff statement. people = session.query(Person).all() The person table does not contain any data (as yet), so when I print the variable people, I get an empty list. I renamed the table referred to in my ORM cla...

Many-to-one relationship in SQLAlchemy

This is a beginner-level question. I have a catalog of mtypes: mtype_id name 1 'mtype1' 2 'mtype2' [etc] and a catalog of Objects, which must have an associated mtype: obj_id mtype_id name 1 1 'obj1' 2 1 'obj2' 3 2 'obj3' [etc] I am trying to do this in SQLAlchemy by creating the f...

dump csv from sqlalchemy

For some reason, I want to dump a table from a database (sqlite3) in the form of a csv file. I'm using a python script with elixir (based on sqlalchemy) to modify the database. I was wondering if there is any way to dump the table I use to csv. I've seen sqlalchemy serializer but it doesn't seem to be what I want. Am I doing it wrong? S...

SQLAlchemy & Complex Queries

I have to implement ACL for an existing application. So I added the a user, group and groupmembers table to the database. I defined a ManyToMany relationship between user and group via the association table groupmembers. In order to protect some ressources of the app (i..e item) I added a additional association table auth_items which s...