composite-primary-key

I want to use Django for a client project that has a legacy database. If at all possible I would like to be able to use the Django admin interface. However, the database has tables with multicolumn primary keys, which I see Django does not like - the admin interface throws a MultipleObjectsReturned exception. What are the options here? I can add new tables, but I can't change existing tables since other projects are already adding data to the database. I've seen other questions mentioning surrogate keys, but it seems like that would require changing the tables. EDIT: The database in question

I need to implement composite keys in hyperledger so that I could have a unique key based on the attributes put into the ledger. The function CreateCompositeKey(objectType string, attributes []string)(string,error) takes in objectType and attributes string. I couldnt find any examples of this online, how are the relevant attributes to be made into the composite key passed and in what way is the output given? So the way Composite keys should be used is make a key first and then push it to the blockchain with PutState(key string, value []byte) error where the hey in PutState is the output of

I have a table named group_table in MySQL with only two columns user_group_id and group_id (both of them are of type VARCHAR ). Both of these columns together form a composite primary key. I need to execute a statement using a sub-select IN() to select rows based on a list of values passed to the query. @Override @SuppressWarnings("unchecked") public List<GroupTable> getList(List<GroupTable> list) { CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder(); CriteriaQuery<GroupTable> criteriaQuery=criteriaBuilder.createQuery(GroupTable.class); Root<GroupTable> root = criteriaQuery.from

I'm trying to understand how to do joins with composite foreign keys on SQLAlchemy and my attempts to do this are failing. I have the following model classes on my toy model (I'm using Flask-SQLAlchemy, but I'm not sure this has anything to do with the problem): # coding=utf-8 from flask import Flask from flask.ext.sqlalchemy import SQLAlchemy app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db' db = SQLAlchemy(app) class Asset(db.Model): __tablename__ = 'asset' user = db.Column('usuario', db.Integer, primary_key=True) profile = db.Column('perfil', db.Integer,