django1/django/db/backends/mysql/validation.py

16 lines
780 B
Python

from django.db.backends import BaseDatabaseValidation
class DatabaseValidation(BaseDatabaseValidation):
def validate_field(self, errors, opts, f):
"""
MySQL has the following field length restriction:
No character (varchar) fields can have a length exceeding 255
characters if they have a unique index on them.
"""
from django.db import models
varchar_fields = (models.CharField, models.CommaSeparatedIntegerField,
models.SlugField)
if isinstance(f, varchar_fields) and f.max_length > 255 and f.unique:
msg = '"%(name)s": %(cls)s cannot have a "max_length" greater than 255 when using "unique=True".'
errors.add(opts, msg % {'name': f.name, 'cls': f.__class__.__name__})