foreign-keys

Using Django 1.8 on Python 3.4.1 with models: class Product(models.Model): name = models.CharField(max_length=255) # some more fields here def __str__(self): return self.name class PricedProduct(models.Model): product = models.ForeignKey(Product, related_name='prices') # some more fields here def __str__(self): return str(self.product) class Coming(models.Model): # some unimportant fields here class ComingProducts(models.Model): coming = models.ForeignKey(Coming) priced_product = models.ForeignKey(PricedProduct) # more unimportant fields and the following admin.py: class ComingProductsInline

I'm having some problems creating a foreign key to an existing table in a mysql database. I have the table exp : +-------------+------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------------+------------------+------+-----+---------+-------+ | EID | varchar(45) | NO | PRI | NULL | | | Comment | text | YES | | NULL | | | Initials | varchar(255) | NO | | NULL | | | ExpDate | date | NO | | NULL | | | InsertDate | date | NO | | NULL | | | inserted_by | int(11) unsigned | YES | MUL | NULL | | +-------------+------------------+------+-----+---------

I have a table of users eg: create table "user" ( id serial primary key, name text not null, superuser boolean not null default false ); and a table with jobs: create table job ( id serial primary key, description text ); the jobs can be assigned to users, but only for superusers. other users cannot have jobs assigned. So I have a table whereby I see which job was assigned to which user: create table user_has_job ( user_id integer references "user"(id), job_id integer references job(id), constraint user_has_job_pk PRIMARY KEY (user_id, job_id) ); But I want to create a check constraint that

I would like optimize the performance of a database that my team is using for an application. I have been looking for areas to add foreign keys, and in turn index those columns to improve the performance of joins. However, many of our tables are joined on an id that is a GUID type, generated upon insertion of an item, and the data associated with that item in other tables is generally has column item_id containing the GUID. I have read that adding clustered indexes to GUID type columns is a very bad decision because the index will need to be constantly reconstructed in order to be effective.