在T-SQL中如何将一列的结果分成多列？

-- 创建一个示例表
CREATE TABLE Sales (
    ProductName VARCHAR(50),
    SalesYear INT,
    SalesAmount DECIMAL(10, 2)
);

-- 插入示例数据
INSERT INTO Sales (ProductName, SalesYear, SalesAmount)
VALUES ('Product A', 2020, 1000),
       ('Product A', 2021, 1500),
       ('Product B', 2020, 2000),
       ('Product B', 2021, 2500);

-- 使用PIVOT操作将SalesAmount按SalesYear进行分组
SELECT *
FROM (
    SELECT ProductName, SalesYear, SalesAmount
    FROM Sales
) AS SourceTable
PIVOT (
    SUM(SalesAmount)
    FOR SalesYear IN ([2020], [2021])
) AS PivotTable;