Databases
StackOverflow2013
Postsdbo
POI want to write a generic function to pair two database fields
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POI want to write a generic function to pair two database fields
    primarykey
    data
    text
    <p>Let's say that I have two teams, <code>"red"</code> and <code>"black"</code>. And let's say that I have a <code>Story</code> class, which presents similar information in two very different ways, depending on your team:</p> <pre><code>class Story(models.Model): red_title = models.CharField() black_title = models.CharField() red_prologue = models.TextField() black_prologue = models.TextField() # ... and so on ... def get_field(self, genericName, team): """Return the field with suffix genericName belonging to the given team. &gt;&gt;&gt;self.get_field("prologue", "red") is self.red_prologue True &gt;&gt;&gt;self.get_field("title", "black") is self.black_title True """ assert(team in ["red", "black"]) specificName = "{}_{}".format(team, genericName) return self.__dict__[specificName] </code></pre> <p>I'm happy with the getter function, but I feel like I should be able to refactor the code which created the fields in the first place. I'd like a function that looks something like this:</p> <pre><code>def make_fields(self, genericName, fieldType, **kwargs): """Create two fields with suffix genericName. One will be 'red_{genericName}' and one will be 'black_{genericName}'. """ for team in ["red", "black"]: specificName = "{}_{}".format(team, genericName) self.__dict__[specificName] = fieldType(**kwargs) </code></pre> <p>But <code>self</code> and <code>__dict__</code> are meaningless while the class is first defined, and I think Django requires that database fields be class variables rather than instance variables.</p> <p>So... is there some way to create this <code>make_fields</code> function within Django, or am I out of luck?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USJeff Hemphill
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COI don't know offhand how to do this (the `Model` metaclass is getting in your way), but have you thought about refactoring by creating a `TeamStory` object, which would have just `title`, `prologue`, etc, and then link `TeamStory`s to a `Story`? This would change the Django admin but everything else should work fairly straightforwardly, and you could easily change your getter to support that.
      singulars
      1. POI want to write a generic function to pair two database fields
      1. USDougal
    2. CORemember that a django model class is a representation of a database table, so if you wouldn't do it to a table in a database, don't do it in the model class.
      singulars
      1. POI want to write a generic function to pair two database fields
      1. USBurhan Khalid
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload