start-pack

myenv/lib/python3.12/site-packages/django/db/models/functions/window.py

@@ -0,0 +1,120 @@
+from django.db.models.expressions import Func
+from django.db.models.fields import FloatField, IntegerField
+
+__all__ = [
+    "CumeDist",
+    "DenseRank",
+    "FirstValue",
+    "Lag",
+    "LastValue",
+    "Lead",
+    "NthValue",
+    "Ntile",
+    "PercentRank",
+    "Rank",
+    "RowNumber",
+]
+
+
+class CumeDist(Func):
+    function = "CUME_DIST"
+    output_field = FloatField()
+    window_compatible = True
+
+
+class DenseRank(Func):
+    function = "DENSE_RANK"
+    output_field = IntegerField()
+    window_compatible = True
+
+
+class FirstValue(Func):
+    arity = 1
+    function = "FIRST_VALUE"
+    window_compatible = True
+
+
+class LagLeadFunction(Func):
+    window_compatible = True
+
+    def __init__(self, expression, offset=1, default=None, **extra):
+        if expression is None:
+            raise ValueError(
+                "%s requires a non-null source expression." % self.__class__.__name__
+            )
+        if offset is None or offset <= 0:
+            raise ValueError(
+                "%s requires a positive integer for the offset."
+                % self.__class__.__name__
+            )
+        args = (expression, offset)
+        if default is not None:
+            args += (default,)
+        super().__init__(*args, **extra)
+
+    def _resolve_output_field(self):
+        sources = self.get_source_expressions()
+        return sources[0].output_field
+
+
+class Lag(LagLeadFunction):
+    function = "LAG"
+
+
+class LastValue(Func):
+    arity = 1
+    function = "LAST_VALUE"
+    window_compatible = True
+
+
+class Lead(LagLeadFunction):
+    function = "LEAD"
+
+
+class NthValue(Func):
+    function = "NTH_VALUE"
+    window_compatible = True
+
+    def __init__(self, expression, nth=1, **extra):
+        if expression is None:
+            raise ValueError(
+                "%s requires a non-null source expression." % self.__class__.__name__
+            )
+        if nth is None or nth <= 0:
+            raise ValueError(
+                "%s requires a positive integer as for nth." % self.__class__.__name__
+            )
+        super().__init__(expression, nth, **extra)
+
+    def _resolve_output_field(self):
+        sources = self.get_source_expressions()
+        return sources[0].output_field
+
+
+class Ntile(Func):
+    function = "NTILE"
+    output_field = IntegerField()
+    window_compatible = True
+
+    def __init__(self, num_buckets=1, **extra):
+        if num_buckets <= 0:
+            raise ValueError("num_buckets must be greater than 0.")
+        super().__init__(num_buckets, **extra)
+
+
+class PercentRank(Func):
+    function = "PERCENT_RANK"
+    output_field = FloatField()
+    window_compatible = True
+
+
+class Rank(Func):
+    function = "RANK"
+    output_field = IntegerField()
+    window_compatible = True
+
+
+class RowNumber(Func):
+    function = "ROW_NUMBER"
+    output_field = IntegerField()
+    window_compatible = True