id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
453	Descriptive error messages in django-admin sql/install 	GrumpySimon	Adrian Holovaty	"It would be very helpful, especially for newer users, to have descriptive error messages when installing/generating SQL for the models.

Example - if you don't specify maxlength=x on a CharField, the resulting error is:

{{{
Error: projectname couldn't be installed. Possible reasons:
  * The database isn't running or isn't configured correctly.
  * At least one of the database tables already exists.
  * The SQL was invalid.
Hint: Look at the output of 'django-admin.py sqlall projectname'. That's the SQL this command wasn't able to run.
The full error: (1064, ""You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'None) NOT NULL,\n "")
}}}

The problem is that this tries to create a field of type ""varchar ( None )"" (Note: This error is on MySQL 4.1.17 - I'm not sure how Postgres/SQLite will handle it, but I'd guess that a ""None"" will fail there too).

A quick look at the code shows that you could do this error checking inside the get_sql_create() function in management.py around line 73 - eg:

{{{
if datatype == 'CharField' and rel_field.maxlength == None:
   print 'Error! ""%s"" must have a max_length value set' % ( f.column )
}}}

However, it's probably not a good idea to pollute management.py with error checking, especially if you want to go the whole route and do complete error checking of all inputs ( eg: check valid parameters for each field type in the database API ).

It would be even better if you could distinguish between the error returns:
  * The database isn't running or isn't configured correctly.
  * At least one of the database tables already exists.
  * The SQL was invalid.

Surely the error code that's returned by the database handler gives enough information to distinguish? 

(Currently running SVN 600)"	enhancement	closed	Database layer (models, ORM)		minor	fixed			Unreviewed	0	0	0	0	0	0