Potential data loss error with ManyToManyField on Django 1.4

[GoogleCodeExporter]

FYI

https://code.djangoproject.com/ticket/18284

From Ticket:
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Attempts to save multiple values for a ManyToManyField? will only save one. It 
appears to follow the same pattern for bulk insert; delete all for parent 
record followed by a single insert. The form collects and passing down the 
appropriate clean_data, but only the first value is inserted in to the database.

This is a regression that will cause data errors for 3rd party db backends that 
have not (or cannot) enable the has_bulk_insert = True database feature. The 
core backends are unaffected because they have enabled the feature.

Discovered issue by using django-mssql. It'll no longer an issue as of 
django-mssql>=1.1a2. Version 1.1a1 added django 1.4 support, so no one should 
be using it on production yet. It's possible this regression only impacts 
django-mssql, but the SQLInsertCompiler is mostly a pass through to core.

A quick source check for django-pyodbc and ibm_db_django show that they have 
not enabled the feature.
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Original issue reported on code.google.com by mman...@gmail.com on 7 May 2012 at 6:29

[GoogleCodeExporter]

Probably a non issue for django-pyodbc. Just make sure if you overwrite 
SqlInsertCompiler that you return multiple sql insert statements when necessary.

Original comment by mman...@gmail.com on 7 May 2012 at 7:39