Fixed #14094 -- Added support for unlimited CharField on PostgreSQL.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index e3b47d173c..060e1be605 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -817,9 +817,14 @@ class Field(RegisterLookupMixin):
         # exactly which wacky database column type you want to use.
         data = self.db_type_parameters(connection)
         try:
-            return connection.data_types[self.get_internal_type()] % data
+            column_type = connection.data_types[self.get_internal_type()]
         except KeyError:
             return None
+        else:
+            # column_type is either a single-parameter function or a string.
+            if callable(column_type):
+                return column_type(data)
+            return column_type % data
 
     def rel_db_type(self, connection):
         """
@@ -1130,14 +1135,19 @@ class BooleanField(Field):
 
 
 class CharField(Field):
-    description = _("String (up to %(max_length)s)")
-
     def __init__(self, *args, db_collation=None, **kwargs):
         super().__init__(*args, **kwargs)
         self.db_collation = db_collation
         if self.max_length is not None:
             self.validators.append(validators.MaxLengthValidator(self.max_length))
 
+    @property
+    def description(self):
+        if self.max_length is not None:
+            return _("String (up to %(max_length)s)")
+        else:
+            return _("String (unlimited)")
+
     def check(self, **kwargs):
         databases = kwargs.get("databases") or []
         return [
@@ -1148,6 +1158,12 @@ class CharField(Field):
 
     def _check_max_length_attribute(self, **kwargs):
         if self.max_length is None:
+            if (
+                connection.features.supports_unlimited_charfield
+                or "supports_unlimited_charfield"
+                in self.model._meta.required_db_features
+            ):
+                return []
             return [
                 checks.Error(
                     "CharFields must define a 'max_length' attribute.",