在postgresql中将我的列转换为行，而不创建任何扩展模块

SELECT 'col1' AS column_name, col1 AS column_value
FROM table_name
UNION ALL
SELECT 'col2' AS column_name, col2 AS column_value
FROM table_name
UNION ALL
SELECT 'col3' AS column_name, col3 AS column_value
FROM table_name
ORDER BY column_name;

SELECT 'col1' AS column_name, col1 AS column_value
FROM table_name
UNION ALL
SELECT 'col2' AS column_name, col2 AS column_value
FROM table_name
UNION ALL
SELECT 'col3' AS column_name, col3 AS column_value
FROM table_name
GROUP BY column_name
ORDER BY column_name;