How do I specify an index for a TextField in Django with a MySql backend?

Question

I've got a model defined in Django that looks (in part) like this:

class Info(models.Model):
    information = models.TextField(max_length = 32, null = True, db_index = True)

However, when I try syncdb with a MySql backend, I get Failed to install index for app.Info model: (1170, "BLOB/TEXT column 'information' used in key specification without a key length")

How can I fix this?

check http://stackoverflow.com/questions/1827063/mysql-error-key-specification-without-a-key-length — okm, Jun 21 '12 at 01:42
Why are you using a BLOB for a 32-character field? Use a normal CharField. — Daniel Roseman, Jun 21 '12 at 06:56

score 8 · Accepted Answer · answered Jun 21 '12 at 13:26

8

The answer is to specify the field as a CharField, not a TextField.

class Info(models.Model):
    information = models.CharField(max_length = 32, null = True, db_index = True)

answered Jun 21 '12 at 13:26

Chris B.

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5

CharField is sufficient here, for max_length = 32, but sometimes it's needed to create text field with no length limit (TEXT in mysql), but with limit for number of chars for index only. – kolen Sep 14 '13 at 19:41

How do I specify an index for a TextField in Django with a MySql backend?

1 Answers1