The main problem with django query fields is that they can’t handle null values. If you try to insert a null value into a query field, django will throw an exception. This can be a problem if you’re trying to use the field in a calculation or in an expression.
I have a model with a field that can be null. I want to query all the objects where this field is null. How do I do this? A: <code>MyModel.objects.filter(field__isnull=True) </code>
This line of code is querying the
MyModel objects and filtering them by the condition that the
field is null.
Null value in Django
A null value is a special type of value in Django that represents the absence of a value. For example, the string “null” is a null value.
When you assign a null value to a variable, Django sets the variable to have the empty string as its content. You can use this feature to create variables that represent nothing.
You can also use null values to indicate the end of data in a list or dictionary. For example, if you want to create a list of strings that contains only the strings “null” and “true”, you can use the following code:
list = [“null”,”true”]
What is query field
The query field is a special field in the Django admin interface that allows you to run SQL queries against your database.