Django 1.7 ValueError: invalid literal for int() with base 10: 'a'
Question: I am getting this error:

    
    
        Operations to perform:
      Apply all migrations: account, jobs, assets, sessions, admin, auth, laptops, contenttypes, mardes
    Running migrations:
      Applying assets.0004_auto_20150202_1707...Traceback (most recent call last):
      File "manage.py", line 10, in <module>
        execute_from_command_line(sys.argv)
      File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
        utility.execute()
      File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 377, in execute
        self.fetch_command(subcommand).run_from_argv(self.argv)
      File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 288, in run_from_argv
        self.execute(*args, **options.__dict__)
      File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 338, in execute
        output = self.handle(*args, **options)
      File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/migrate.py", line 160, in handle
        executor.migrate(targets, plan, fake=options.get("fake", False))
      File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 63, in migrate
        self.apply_migration(migration, fake=fake)
      File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 97, in apply_migration
        migration.apply(project_state, schema_editor)
      File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/migration.py", line 107, in apply
        operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
      File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/operations/fields.py", line 37, in database_forwards
        field,
      File "/usr/local/lib/python2.7/dist-packages/django/db/backends/mysql/schema.py", line 42, in add_field
        super(DatabaseSchemaEditor, self).add_field(model, field)
      File "/usr/local/lib/python2.7/dist-packages/django/db/backends/schema.py", line 397, in add_field
        definition, params = self.column_sql(model, field, include_default=True)
      File "/usr/local/lib/python2.7/dist-packages/django/db/backends/schema.py", line 120, in column_sql
        default_value = self.effective_default(field)
      File "/usr/local/lib/python2.7/dist-packages/django/db/backends/schema.py", line 183, in effective_default
        default = field.get_db_prep_save(default, self.connection)
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 1722, in get_db_prep_save
        return self.related_field.get_db_prep_save(value, connection=connection)
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init__.py", line 627, in get_db_prep_save
        prepared=False)
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init__.py", line 907, in get_db_prep_value
        value = self.get_prep_value(value)
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init__.py", line 915, in get_prep_value
        return int(value)
    ValueError: invalid literal for int() with base 10: 'a'
    

When running python manage.py migrate.

For this app there is only an admin.py and models.py file, everything else is
blank. Here is the models.py file:

    
    
    from django.db import models
    from django.contrib.auth.models import User
    
    class Asset_type(models.Model):
        name = models.CharField(max_length=50)
    
        def __str__(self):
            return self.name
    
    class Asset_os(models.Model):
        name = models.CharField(max_length=50)
    
        def __str__(self):
            return self.name
    
    class Asset_cs_status(models.Model):
        status = models.CharField(max_length=50)
    
        def __str__(self):
            return self.status
    
    class Asset_floor(models.Model):
        name = models.CharField(max_length=50)
    
        def __str__(self):
            return self.name
    
    class Asset(models.Model):
        DLO = (
                ('0', 'Desktop'),
                ('1', 'Laptop'),
                ('2', 'Other'),
                )
        user = models.ForeignKey(User)
        asset_type = models.ForeignKey(Asset_type)
        asset_os = models.ForeignKey(Asset_os)
        asset_cs_status = models.ForeignKey(Asset_cs_status)
        asset_floor = models.ForeignKey(Asset_floor)
        ppl = models.CharField(max_length=40, unique=True)
        desktop_laptop = models.CharField(max_length=1, choices=DLO) 
        date_of_purchase = models.DateField()
        extra_info = models.CharField(max_length=250, default='-')
        pc_name = models.CharField(max_length=100, null=True, default='-')
        bookable = models.BooleanField(default=False)
        image = models.ImageField(upload_to='asset_files/%Y/%m/%d', null=True, blank=True, help_text='Optional')
    
        def __str__(self):
            return self.asset_type.name+' ('+self.ppl+')' 
    

Please let me know if you need to see anything else. BC


Answer: The solution was found looking in the assets.0004_auto_20150202_1707 file
under assets > migrations

It had picked up a default value I had typed in previously. Removing the files
and regenerating them solved the problem.

