The Django version is definitely worse: it has race conditions. If there are two threads (two queries) going through the code simultaneously , they might both end up trying to insert the object, and one of them will get an error. The SQL version does not have the issue. You mentioned this in a single sentence in the discussion, but this is a major win for the SQL version.
The SQL version is bad, too, since it is subject to SQL injection. I am not sure what the proper way to do that with Django is, though.
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Seconding this comment. The Django ORM version should basically never be used in any real world situation. Very susceptible to race conditions.
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The Django version is definitely worse: it has race conditions. If there are two threads (two queries) going through the code simultaneously , they might both end up trying to insert the object, and one of them will get an error. The SQL version does not have the issue. You mentioned this in a single sentence in the discussion, but this is a major win for the SQL version. The SQL version is bad, too, since it is subject to SQL injection. I am not sure what the proper way to do that with Django is, though.