I want to delete a particular record. Such as
delete from table_name where id = 1;
How can I do this in a django model
?
MyModel.objects.get(pk=1).delete()
this will raise exception if the object with specified primary key doesn't exist because at first it tries to retrieve the specified object.
MyModel.objects.filter(pk=1).delete()
this wont raise exception if the object with specified primary key doesn't exist and it directly produces the query
DELETE FROM my_models where id=1
delete() method is used to delete model instances from a database.This method immediately deletes the object. this method returns the number of object deleted.
Example:
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data_to_be_deleted = Modelname.objects.get(fieldname = value)
data_to_be_deleted.delete()
As get method returns a single object from queryset only single record will be deleted.If value supplied doesn't exist this will throw an error.If there are multilpe records in table for same value then also it will throw an error so good practice is to use a single unique value while using get.
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For condition based deletion filter method is used on queryset and then delete is called.
data_to_be_deleted = Modelname.objects.filter(fieldname = value)
data_to_be_deleted.delete()
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For deletion of all model instances/records from database table you need to call delete method on all
data_to_be_deleted = Modelname.objects.all()
data_to_be_deleted.delete()
Note: code can be written in single line as Modelname.objects.all().delete() but for clear understanding i have used multiple lines.
you can delete the objects directly from the admin panel or else there is also an option to delete specific or selected id from an interactive shell by typing in python3 manage.py shell (python3 in Linux). If you want the user to delete the objects through the browser (with provided visual interface) e.g. of an employee whose ID is 6 from the database, we can achieve this with the following code, emp = employee.objects.get(id=6).delete()
THIS WILL DELETE THE EMPLOYEE WITH THE ID is 6.
If you wish to delete the all of the employees exist in the DB instead of get(), specify all() as follows: employee.objects.all().delete()
It is as simple as calling the following.
SomeModel.objects.get(pk=1).delete()
# Or
SomeModel.objects.filter(pk=1).delete()
# SQL equivalent
# delete from table_name where id = 1;
In case you want to remove multiple records based on id,
use the __in
query lookup
SomeModel.objects.fitler(pk__in=[1,2,3,4,5,...]).delete()
# SQL equivalent
# delete from table_name where id in (1,2,4,5,...);
In case you want to delete all records, use .all()
to retrieve all queries,
then .delete()
.
SomeModel.objects.all().delete()
# SQL equivalent
# delete from table_name;