1 from django.db.backends import BaseDatabaseValidation

     2 

     3 class DatabaseValidation(BaseDatabaseValidation):

     4     def validate_field(self, errors, opts, f):

     5         "Prior to MySQL 5.0.3, character fields could not exceed 255 characters"

     6         from django.db import models

     7         from django.db import connection

     8         db_version = connection.get_server_version()

     9         if db_version < (5, 0, 3) and isinstance(f, (models.CharField, models.CommaSeparatedIntegerField, models.SlugField)) and f.max_length > 255:

    10             errors.add(opts,

    11                 '"%s": %s cannot have a "max_length" greater than 255 when you are using a version of MySQL prior to 5.0.3 (you are using %s).' % 

    12                 (f.name, f.__class__.__name__, '.'.join([str(n) for n in db_version[:3]])))

    13