Add logical deletion custom column value

docs/usage/crud.md

@@ -202,7 +202,7 @@ count = await user_crud.delete_model_by_column(
 )
 ```
 
-逻辑删除会把标记字段设为 `True`。如果模型包含删除时间字段，也会写入当前时间。
+逻辑删除默认会把标记字段设为 `True`。如果模型包含删除时间字段，也会写入当前时间。
 
 ```python
 count = await user_crud.delete_model_by_column(
@@ -214,6 +214,20 @@ count = await user_crud.delete_model_by_column(
 )
 ```
 
+如果逻辑删除标记需要写入自定义值，可以使用 `deleted_flag_value`。该参数也支持 SQLAlchemy 表达式，例如把 `deleted` 字段写成当前行的 `id`。
+
+```python
+count = await user_crud.delete_model_by_column(
+    session,
+    logical_deletion=True,
+    deleted_flag_column='deleted',
+    deleted_flag_value=User.id,
+    deleted_at_column='deleted_time',
+    id=1,
+    deleted=0
+)
+```
+
 ## 统计和存在性
 
 ```python

sqlalchemy_crud_plus/crud.py

@@ -751,6 +751,7 @@ async def delete_model_by_column(
         allow_multiple: bool = False,
         logical_deletion: bool = False,
         deleted_flag_column: str = 'is_deleted',
+        deleted_flag_value: Any = True,
         deleted_at_column: str = 'deleted_at',
         deleted_at_factory: datetime | Callable[[], datetime] | None = None,
         flush: bool = False,
@@ -764,6 +765,7 @@ async def delete_model_by_column(
         :param allow_multiple: If `True`, allows deleting multiple records that match the filters
         :param logical_deletion: If `True`, enable logical deletion instead of physical deletion
         :param deleted_flag_column: Column name for logical deletion flag
+        :param deleted_flag_value: Value written to logical deletion flag column
         :param deleted_at_column: Column name for delete time，automatic judgment
         :param deleted_at_factory: The delete time value or factory function
         :param flush: If `True`, flush all object changes to the database
@@ -785,7 +787,7 @@ async def delete_model_by_column(
             if total_count > 1:
                 raise MultipleResultsError(f'Only one record is expected to be deleted, found {total_count} records.')
 
-        data: dict[str, Any] = {deleted_flag_column: True}
+        data: dict[str, Any] = {deleted_flag_column: deleted_flag_value}
 
         if deleted_at_column in self.model_column_names:
             if deleted_at_factory is None:

tests/models/basic.py

@@ -16,8 +16,10 @@ class Ins(Base):
     id: Mapped[int] = mapped_column(init=False, primary_key=True, index=True, autoincrement=True)
     name: Mapped[str] = mapped_column(String(64))
     is_deleted: Mapped[bool] = mapped_column(default=False)
+    deleted: Mapped[int] = mapped_column(default=0)
     created_time: Mapped[datetime] = mapped_column(init=False, default_factory=datetime.now)
     updated_time: Mapped[datetime | None] = mapped_column(init=False, onupdate=datetime.now)
+    deleted_time: Mapped[datetime | None] = mapped_column(init=False, default=None)
 
 
 class InsPks(Base):

tests/test_delete.py

@@ -1,3 +1,5 @@
+from datetime import datetime
+
 import pytest
 
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -148,6 +150,34 @@ async def test_logical_delete_single_record(db: AsyncSession, sample_ins: list[I
         assert updated_item.is_deleted is True
 
 
+@pytest.mark.asyncio
+async def test_logical_delete_with_deleted_flag_value_expression(
+    db: AsyncSession, sample_ins: list[Ins], crud_ins: CRUDPlus[Ins]
+):
+    item = sample_ins[0]
+
+    deleted_time = datetime(2024, 1, 1, 12, 0, 0)
+
+    async with db.begin():
+        count = await crud_ins.delete_model_by_column(
+            db,
+            logical_deletion=True,
+            deleted_flag_column='deleted',
+            deleted_flag_value=crud_ins.model.id,
+            deleted_at_column='deleted_time',
+            deleted_at_factory=deleted_time,
+            id=item.id,
+            deleted=0,
+        )
+
+    assert count == 1
+
+    updated_item = await crud_ins.select_model(db, item.id)
+    assert updated_item is not None
+    assert updated_item.deleted == item.id
+    assert updated_item.deleted_time == deleted_time
+
+
 @pytest.mark.asyncio
 async def test_logical_delete_multiple_records(db: AsyncSession, sample_ins: list[Ins], crud_ins: CRUDPlus[Ins]):
     before_count = await crud_ins.count(db, is_deleted=False)