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PODjango How to make a ForeignKey use a default?
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copied!<p>I having a problem getting a ForeignKey to default to zero, it keeps telling me that the field is required, or if I try a different iteration it'll complain the field cannot be null.</p> <p>I am not sure what I am doing wrong, but I need the ForeignKey to be defaulted to zero if its null.</p> <p>I am experimenting with an idea to hold all contracts between several different entities (ie: companies and employees, companies and sponsors, etc, companies and suppliers, etc).</p> <p>The relationships are all working, however my ForeignKey statements are not letting me use a default of 0 (zero).</p> <pre><code># relationships # Only the company field should be required, the others are optional # This is so you can link a company with either a sponsor OR a worker # sponsor = models.ForeignKey('Sponsor', null=True, default=0, blank=False) company = models.ForeignKey('Company') worker = models.ForeignKey('Worker', null=False, default=0, blank=False) # possible future relationships (not implemented) #suppliers = models.ForeignKey('Supplier', null=True, default=0, blank=False) </code></pre> <p>Ideally, I would like it so that only the company field is required, and the others are purely optional and will default to zero.</p> <p>The idea is to have 1 table to rule/manage all the contracts between different entities.</p> <blockquote> <p>Pseduocode</p> <p>Contracts; id = 1 | company_id = 1 | sponsor_id = 0 | worker_id = 1 | length = 10 | salary = 10000</p> <p>// etc</p> </blockquote> <p>I have tried the following iterations.</p> <pre><code># models.ForeignKey('Sponsor', null=False, default=0, blank=True) # This makes the field required # models.ForeignKey('Sponsor', null=True, default=0, blank=True) # This complains that "Contracts.sponsor" does not allow null values. </code></pre> <p>Any pointers on how to make a make a ForeignKey use a default would be greatly appreciated.</p> <p>Many thanks.</p> <p>Edit. Adding the code that is causing the errors; This is a cut-down version of the code.</p> <pre><code>// company.py class Company(models.Model): """(Company description)""" sponsorContracts = models.ManyToManyField('Sponsor', through='Contracts', db_column='sponsor_id') employees = models.ManyToManyField('Worker', through='Contracts', db_column='worker_id') // contracts.py class Contracts(models.Model): """(Contracts description)""" # relationships sponsor = models.ForeignKey('Sponsor', null=True, default=0, blank=True) company = models.ForeignKey('Company') worker = models.ForeignKey('Worker', null=False, default=0, blank=False) // worker.py class Worker(models.Model): """(A list of employees)""" employer = models.ManyToManyField('Company', through='Contracts', db_column='company_id') // sponsor.py class Sponsor(models.Model): """(A list of sponsors)""" sponsorContracts = models.ManyToManyField('Company', through='SponsorContracts') </code></pre>

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