To each object in the QuerySet that is returned. Reference to a field on the model (or any related models), or an aggregateĮxpression (averages, sums, etc.) that has been computed over the objects thatĪre related to the objects in the QuerySet.Įach argument to annotate() is an annotation that will be added Force evaluation of a QuerySet by calling list() onĪnnotate() ¶ annotate( * args, ** kwargs) ¶Īnnotates each object in the QuerySet with the provided list of queryĮxpressions. Django provides aĬount() method for precisely this reason. Note: If you only need to determine the number of records in the set (andĭon’t need the actual objects), it’s much more efficient to handle a countĪt the database level using SQL’s SELECT COUNT(*). This, as you might expect, returns the length of the result list. A QuerySet is evaluated when you call len() on it. Immediately see your results when using the API interactively. This is for convenience in the Python interactive interpreter, so you can A QuerySet is evaluated when you call repr() on it. Purposes of this section is that the results are read from the database. See the following section for details of what Translate well into SQL and it would not have a clear meaning either. More filters, or modifying ordering) is not allowed, since that does not Slicing a QuerySet that has beenĪlso note that even though slicing an unevaluated QuerySet returnsĪnother unevaluated QuerySet, modifying it further (e.g., adding Will execute the database query if you use the “step” parameter of slice QuerySet usually returns another unevaluated QuerySet, but Django As explained in Limiting QuerySets, a QuerySet canīe sliced, using Python’s array-slicing syntax. Support for asynchronous iteration was added.
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