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I have database created by Django model, where status and id and username are the fields of the table Messages.
I need to count the number of rows where status value= 0 for a particular username.
This is my incomplete code:
Message_me = Messages.objects.get(username='myname') 
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Use Django's count() QuerySet method — simply append count() to the end of the appropriate QuerySet. Generate an aggregate over the QuerySet — Aggregation is when you "retrieve values that are derived by summarizing or aggregating a collection of objects." Ref: Django Aggregation Documentation.
Solution. Create your QuerySet by querying the Model as you are used to. Then simply append a . count() to your chain and you receive the number.
Try this code:
Message_me = Messages.objects.filter(username='myname', status=0).count() You can either use Python's len() or use the count() method on any queryset depending on your requirements. Also note, using len() will evaluate the queryset so it's always feasible to use the provided count() method.
It can be used as follows:
message_count = models.Messages.objects.filter(username='username', status=0).count() Alternatively, (if you do not worry about performance) you can also use len():
message_count = len(models.Messages.objects.filter(username='username', status=0)) You should also go through the QuerySet API Documentation for more information.
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