tsql更新查询，即运行时更新字段

Question

我有下表（表1）：

+----+-----+
|Type|Value|
+----+-----+
|P   |4    |
+----+-----+
|P   |20   |
+----+-----+
|S   |0    |
+----+-----+
|S   |0    |
+----+-----+
|S   |0    |
+----+-----+

我正在运行以下查询：

update Table1 set value = ( select sum(value) FROM Table1 ) where Type = 'S'

对于所有值为'S'

的字段，结果为24

我需要考虑运行时更新的值。 结果我需要：

+----+-----+
|Type|Value|
+----+-----+
|P   |4    |
+----+-----+
|P   |20   |
+----+-----+
|S   |24   |
+----+-----+
|S   |48   |
+----+-----+
|S   |96   |
+----+-----+

如何在简单查询中完成此操作？

谢谢，

Answer 1

DECLARE @ID int
DECLARE cur CURSOR local select ID from table1 where Type = 'S'
FETCH cur into @ID
WHILE @@FETCH_STATUS=0
BEGIN
update Table1 set value = ( select sum(value) FROM Table1 ) where ID=@ID
FETCH cur into @ID
END
Close cur
DEALLOCATE cur