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| -rw-r--r-- | docs/topics/db/optimization.txt | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/docs/topics/db/optimization.txt b/docs/topics/db/optimization.txt index 0f39fae103..9d22b980bd 100644 --- a/docs/topics/db/optimization.txt +++ b/docs/topics/db/optimization.txt @@ -367,6 +367,37 @@ Note that there are a number of :meth:`caveats to this method <django.db.models.query.QuerySet.bulk_create>`, so make sure it's appropriate for your use case. +Update in bulk +-------------- + +.. versionadded:: 2.2 + +When updating objects, where possible, use the +:meth:`~django.db.models.query.QuerySet.bulk_update()` method to reduce the +number of SQL queries. Given a list or queryset of objects:: + + entries = Entry.objects.bulk_create([ + Entry(headline='This is a test'), + Entry(headline='This is only a test'), + ]) + +The following example:: + + entries[0].headline = 'This is not a test' + entries[1].headline = 'This is no longer a test' + Entry.objects.bulk_update(entries, ['headline']) + +...is preferable to:: + + entries[0].headline = 'This is not a test' + entries.save() + entries[1].headline = 'This is no longer a test' + entries.save() + +Note that there are a number of :meth:`caveats to this method +<django.db.models.query.QuerySet.bulk_update>`, so make sure it's appropriate +for your use case. + Insert in bulk -------------- |