仅当另一列的值更改SQL Server时才自动增加该值

您可以使用CTE来做到这一点。

WITH CTE (Col1, RowNumber)
AS
(
    SELECT <YOUR_COLUMN_NAME_HERE> AS Col1, ROW_NUMBER() OVER (ORDER BY Col1) As RowNumber
    FROM <YOUR_TABLE_NAME_HERE>
)

SELECT Col1, 
(
    SELECT COUNT(DISTINCT Col1)
    FROM CTE InnerCTE
    WHERE InnerCTE.RowNumber <= OuterCTE.RowNumber
) As NumberOfDistinctItemsInCol1
FROM CTE OuterCTE

请确保将<YOUR_COLUMN_NAME_HERE>替换为您的实际列名，并将<YOUR_TABLE_NAME_HERE>替换为您的实际表名。