SQL - 如何转置

SQL中的数据转置操作：掌握转置技巧优化数据处理

sql
SELECT
    MAX(CASE WHEN column_name = 'Value1' THEN value END) AS 'New_Column1',
    MAX(CASE WHEN column_name = 'Value2' THEN value END) AS 'New_Column2',
    MAX(CASE WHEN column_name = 'Value3' THEN value END) AS 'New_Column3'
FROM your_table
GROUP BY common_column;

sql
SELECT *
FROM your_table
PIVOT (
    MAX(value)
    FOR column_name IN ('Value1', 'Value2', 'Value3')
) AS pivoted_table;

sql
SELECT
    Date,
    MAX(CASE WHEN Product = 'Product_A' THEN Sales END) AS 'Product_A_Sales',
    MAX(CASE WHEN Product = 'Product_B' THEN Sales END) AS 'Product_B_Sales'
FROM sales_table
GROUP BY Date;