SQL Server ,将列转换为行

ID | Name | Age | Gender
------------------------
1  | John | 25  | Male
2  | Mary | 30  | Female

SELECT ID, ColumnName, Value
FROM (
    SELECT ID, Name, Age, Gender
    FROM YourTable
) AS SourceTable
UNPIVOT (
    Value FOR ColumnName IN (Name, Age, Gender)
) AS UnpivotTable;

ID | ColumnName | Value
------------------------
1  | Name       | John
1  | Age        | 25
1  | Gender     | Male
2  | Name       | Mary
2  | Age        | 30
2  | Gender     | Female

SELECT ID, ColumnName, Value
FROM (
    SELECT ID,
           CASE ColumnNumber WHEN 1 THEN Name WHEN 2 THEN Age WHEN 3 THEN Gender END AS Value,
           CASE ColumnNumber WHEN 1 THEN 'Name' WHEN 2 THEN 'Age' WHEN 3 THEN 'Gender' END AS ColumnName
    FROM YourTable
    CROSS JOIN (
        SELECT 1 AS ColumnNumber
        UNION ALL SELECT 2
        UNION ALL SELECT 3
    ) AS ColumnNumbers
) AS SourceTable
WHERE Value IS NOT NULL;