MYSQL 行轉列 Pivot 動態 思路

SQL Server行轉列、不確定列的行轉列 - 農村的碼農 - 博客園
https://www.cnblogs.com/kylan/p/10844414.html

mysql 行轉列 列轉行 - 平凡希 - 博客園
https://www.cnblogs.com/xiaoxi/p/7151433.html

Pivot Tables in MySQL
https://codingsight.com/pivot-tables-in-mysql/

Pivoting in MySQL
http://mysql.rjweb.org/doc.php/pivot

MySQL - Creating a pivot query | mysql Tutorial
https://riptutorial.com/mysql/example/10441/creating-a-pivot-query

Mysql - MySQL Pivot Handling Values
https://www.howtobuildsoftware.com/index.php/how-do/cnlj/mysql-pivot-mysql-pivot-handling-values

How can I return pivot table output in MySQL? - Stack Overflow
https://stackoverflow.com/questions/7674786/how-can-i-return-pivot-table-output-in-mysql

Artful Common Queries
http://www.artfulsoftware.com/infotree/qrytip.php?id=78