SQL Server中行转列方法详细讲解

CREATE TABLE SalesData
(
SalesID INT PRIMARY KEY,
SalesDate DATE,
SalesAmount DECIMAL(10, 2)
);

INSERT INTO SalesData VALUES (1, ‘2023-01-01', 1000);
INSERT INTO SalesData VALUES (2, ‘2023-02-01', 1500);
INSERT INTO SalesData VALUES (3, ‘2023-03-01', 1200);

SELECT *
FROM
(
    SELECT SalesDate, SalesAmount, DATEPART(MONTH, SalesDate) AS Month
    FROM SalesData
) AS SourceData
PIVOT
(
    SUM(SalesAmount)
    FOR Month IN ([1], [2], [3])
) AS PivotTable;

SELECT SalesDate,
       SUM(CASE WHEN DATEPART(MONTH, SalesDate) = 1 THEN SalesAmount END) AS Month1SalesAmount,
       SUM(CASE WHEN DATEPART(MONTH, SalesDate) = 2 THEN SalesAmount END) AS Month2SalesAmount,
       SUM(CASE WHEN DATEPART(MONTH, SalesDate) = 3 THEN SalesAmount END) AS Month3SalesAmount
FROM SalesData
GROUP BY SalesDate;

DECLARE @columns NVARCHAR(MAX), @sql NVARCHAR(MAX);

– 构建列名列表
SELECT @columns = STUFF((SELECT DISTINCT ‘,' + QUOTENAME(CONVERT(VARCHAR(2), DATEPART(MONTH, SalesDate)))
FROM SalesData
FOR XML PATH(‘'), TYPE).value(‘.', ‘NVARCHAR(MAX)'), 1, 1, ‘');

– 构建动态 SQL
SET @sql = N'SELECT SalesDate, ' + @columns + '
FROM
(
SELECT SalesDate, SalesAmount, CONVERT(VARCHAR(2), DATEPART(MONTH, SalesDate)) AS Month
FROM SalesData
) AS SourceData
PIVOT
(
SUM(SalesAmount)
FOR Month IN (' + @columns + ‘)
) AS PivotTable;';

– 执行动态 SQL
EXEC sp_executesql @sql;