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PODjango manytomany: adding multiple, non-unique relationships?
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  1. PODjango manytomany: adding multiple, non-unique relationships?
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    copied!<p>I'm building an app that puts together the hardware of a computer. This is my first time working with django. Say I have the following models:</p> <pre><code>class Memory(models.Model): partNum = models.CharField() capacity = models.CharField() class Computer(models.Model): name = models.CharField() memory = models.ManyToManyField(Memory) # also has cpus, hard drives, and motherboard, but focus on memory for now </code></pre> <p>One memory object can belong to many computer objects, and one computer object can have many memory objects - hense Many-To-Many. However, computers require the same exact memory sticks installed if using more than one. </p> <p>Yet django's manytomany field (by default?) only allows one instance of a memory-computer relationship, it must me unique. Any way around this?</p> <p>If I try, in the admin page, to add many of the same memory objects to a computer, it says "Computer-memory relationship with this Computer and Memory already exists". If I try adding more than once the same memory object to a server object in the manage.py shell, it appears that only one memory object was added. If I try to manually edit the database to have a duplicate entry, I get an error saying that the entry already exists. I see that in the database structure, some sorta "unique together" index thingy is enforcing is enforcing this. If I altered the table to remove that clause, would that solve my problem? Probably not unless the django manager is more stupid than expected.</p> <p>What are my options? Write my own intermediary models and use the <code>through</code> construct? But then I won't get to use the cool filter_horizontal widget! Rewrite my Computer model to have a Foreign Key field plus a field for the number of memory object? But then I won't get the ManyToMany API facilities. Help!</p>
 

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