Initial commit

folkugat_web/model/sql.py

@@ -0,0 +1,74 @@
+from __future__ import annotations
+
+import dataclasses
+import datetime
+import enum
+from abc import abstractmethod
+from typing import Generic, Optional, Protocol, TypeVar
+
+
+class Comparable(Protocol):
+    @abstractmethod
+    def __gt__(self: T, other: T, /) -> bool:
+        pass
+
+    @abstractmethod
+    def __ge__(self: T, other: T, /) -> bool:
+        pass
+
+    @abstractmethod
+    def __lt__(self: T, other: T, /) -> bool:
+        pass
+
+    @abstractmethod
+    def __le__(self: T, other: T, /) -> bool:
+        pass
+
+
+T = TypeVar("T", bound=Comparable)
+
+
+@dataclasses.dataclass
+class Range(Generic[T]):
+    gt: Optional[T] = None
+    gte: Optional[T] = None
+    lt: Optional[T] = None
+    lte: Optional[T] = None
+
+    def lower_bound(self) -> Optional[tuple[T, bool]]:
+        if self.gt is None and self.gte is None:
+            return None
+        elif self.gt is not None and self.gte is not None:
+            lb = self.gt if (self.gt > self.gte) else self.gte
+            eq = self.gt < self.gte
+            return lb, eq
+        elif self.gt is not None:
+            return self.gt, False
+        elif self.gte is not None:
+            return self.gte, True
+
+    def upper_bound(self) -> Optional[tuple[T, bool]]:
+        if self.lt is None and self.lte is None:
+            return None
+        elif self.lt is not None and self.lte is not None:
+            ub = self.lt if (self.lt < self.lte) else self.lte
+            eq = self.lt > self.lte
+            return ub, eq
+        elif self.lt is not None:
+            return self.lt, False
+        elif self.lte is not None:
+            return self.lte, True
+
+
+class Order(enum.Enum):
+    ASCENDING = 'ASC'
+    DESCENDING = 'DESC'
+
+
+ColT = TypeVar("ColT")
+
+
+@dataclasses.dataclass
+class OrderCol(Generic[ColT]):
+    column: ColT
+    order: Order