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I have a Django QuerySet, and I want to get a Q object out of it. (i.e. that holds the exact same query as that queryset.)
Is that possible? And if so, how?
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Slicing. As explained in Limiting QuerySets, a QuerySet can be sliced, using Python's array-slicing syntax. Slicing an unevaluated QuerySet usually returns another unevaluated QuerySet , but Django will execute the database query if you use the “step” parameter of slice syntax, and will return a list.
Q object encapsulates a SQL expression in a Python object that can be used in database-related operations. Using Q objects we can make complex queries with less and simple code. For example, this statement returns if the question starts with 'who' or with 'what'.
QuerySet s are lazy Though this looks like three database hits, in fact it hits the database only once, at the last line ( print(q) ). In general, the results of a QuerySet aren't fetched from the database until you “ask” for them.
No, but you could create the Q object first, and use that; alternatively, create your query as a dict, and pass that to your filter method and the Q object.
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