value too long for type character varying(100)----recently switched database, didn't do anything in db

Question

I recently switched to postgresql, I thought everything worked fine until I realized when I make post I get value too long for type character varying(100). Now I googled it, and saw some similar questions but when I tried some solutions there none of them worked. I will explain why my question is different in my opinion. I have this code in models.py

class Post(models.Model):
    url = models.URLField(max_length=250, blank=True, null=True)

    slug = models.CharField(max_length=255, unique=True)
    objects = models.Manager()    

@property

def save(self, *args, **kwargs):
    self.slug = uuslug(self.title, instance=self, max_length=255)
    super(Post, self).save(*args, **kwargs)

As I saw some recommended solutions, I did try changing my max_length to 100. I have no idea why this is happening, I don't have anything in db. I recently switched to postgresql. Can you help me why this error is occurring and how I can fix it? should I move away from uuslug?

Full model

.
class Category(models.Model): 

    name = models.CharField(max_length=128, unique=True)
    description = models.TextField(verbose_name=('describe'))
    author = models.ForeignKey(settings.AUTH_USER_MODEL)


    def __unicode__(self): 
        return self.name

    def get_absolute_url(self):
        return "/category/%s/" %self.name

def my_handler(sender, instance, created, **kwargs):
    action.send(instance.author, verb='following', target=Category)
post_save.connect(my_handler, sender=Category)


class Post(models.Model):
    category = models.ForeignKey(Category, verbose_name=('community'))
    pub_date = models.DateTimeField(auto_now_add = True)
    url = models.URLField(max_length=250, blank=True, null=True)
    video = EmbedVideoField(verbose_name='link',help_text="Youtube", blank=True, null=True) 

    title = models.CharField(max_length = 50)
    moderator = models.ForeignKey(User)
    views = models.IntegerField(default=0)
    slug = models.CharField(max_length=255, unique=True)
    objects = models.Manager()            # default manager
    content = RichTextUploadingField(config_name='default')
    rank_score = models.FloatField(default= 1)
    image = models.ImageField(upload_to='images',blank=True, null=True)
    thumbnail = models.ImageField(upload_to='images', blank=True, null=True)


    @property
    def domain(self):
        long_url = urlparse(self.url).netloc if self.url else "be kind to one another"
        return long_url.split('.', 1)[1] if long_url.split('.', 1)[0] == 'www' else long_url
    def save(self, *args, **kwargs):
        self.slug = uuslug(self.title, instance=self, max_length=255)
        super(Post, self).save(*args, **kwargs)
    def __unicode__(self):
        return self.title 

Here's full Traceback

T

raceback:
File "env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/base.py" in view
  71.             return self.dispatch(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/utils/decorators.py" in _wrapper
  34.             return bound_func(*args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/contrib/auth/decorators.py" in _wrapped_view
  22.                 return view_func(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/utils/decorators.py" in bound_func
  30.                 return func.__get__(self, type(self))(*args2, **kwargs2)
File "ebagu/main/views.py" in dispatch
  191.      return super(PostCreateView, self).dispatch(request, *args, **kwargs)       
File "env/local/lib/python2.7/site-packages/django/views/generic/base.py" in dispatch
  89.         return handler(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
  249.         return super(BaseCreateView, self).post(request, *args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
  215.             return self.form_valid(form)
File "ebagu/main/views.py" in form_valid
  186.          self.object.save()
File "ebagu/main/models.py" in save
  66.       super(Post, self).save(*args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/db/models/base.py" in save
  734.                        force_update=force_update, update_fields=update_fields)
File "env/local/lib/python2.7/site-packages/django/db/models/base.py" in save_base
  762.             updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
File "env/local/lib/python2.7/site-packages/django/db/models/base.py" in _save_table
  846.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "env/local/lib/python2.7/site-packages/django/db/models/base.py" in _do_insert
  885.                                using=using, raw=raw)
File "env/local/lib/python2.7/site-packages/django/db/models/manager.py" in manager_method
  127.                 return getattr(self.get_queryset(), name)(*args, **kwargs)
File "env/local/lib/python2.7/site-packages/django/db/models/query.py" in _insert
  920.         return query.get_compiler(using=using).execute_sql(return_id)
File "env/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  974.                 cursor.execute(sql, params)
File "env/local/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
  79.             return super(CursorDebugWrapper, self).execute(sql, params)
File "env/local/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
  64.                 return self.cursor.execute(sql, params)
File "env/local/lib/python2.7/site-packages/django/db/utils.py" in __exit__
  97.                 six.reraise(dj_exc_type, dj_exc_value, traceback)
File "env/local/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
  64.                 return self.cursor.execute(sql, params)

Exception Type: DataError at /add_post/
Exception Value: value too long for type character varying(100)

Answer 1

Look into database.

---

Quick psql tutorial

Start postgres client shell, eg. with python manage.py dbshell. Something like this shows:

ebagu=>

The lines

File "ebagu/main/models.py" in save
  66.       super(Post, self).save(*args, **kwargs)

show you are trying to save model Post in what I assume is app main. If you didn't change table in Post's Meta, the table should be something like main_post.

You want to display all tables in postgres shell with command:

\d

It will list tables in a similar fashion:

                          List of relations
 Schema |               Name                |     Type      | Owner  
--------+-----------------------------------+---------------+--------
 public | django_migrations                 | table         | hruske
 public | django_migrations_id_seq          | sequence      | hruske
 public | django_session                    | table         | hruske

If you want to check the details of the table django_session you can do:

\d django_session

And you get something like this:

             Table "public.django_session"
    Column    |           Type           | Modifiers 
--------------+--------------------------+-----------
 session_key  | character varying(40)    | not null
 session_data | text                     | not null
 expire_date  | timestamp with time zone | not null
Indexes:
    "django_session_pkey" PRIMARY KEY, btree (session_key)
    "django_session_de54fa62" btree (expire_date)
    "django_session_session_key_461cfeaa630ca218_like" btree (session_key varchar_pattern_ops)

Here you can see which fields are defined as varchar(100).

If you want to know more psql commands, type \?