我有两个mysql表,它们有以下模式。
学生:
+------------+--------------+
| student_id | student_name |
+------------+--------------+
| 1 | John Doe |
+------------+--------------+
| 2 | Robert Brown |
+------------+--------------+
| 3 | Charlie Cox |
+------------+--------------+
学科:
+------------+--------------+
| student_id | subject_name |
+------------+--------------+
| 1 | History |
+------------+--------------+
| 1 | Biology |
+------------+--------------+
| 1 | Mathematics |
+------------+--------------+
| 2 | Literature |
+------------+--------------+
| 2 | Physics |
+------------+--------------+
| 2 | Mathematics |
+------------+--------------+
| 3 | Literature |
+------------+--------------+
| 3 | Geography |
+------------+--------------+
现在我想要一个结果矩阵below:-
+--------------+---------+-----------+---------+------------+-------------+---------+
| student_name | Biology | Geography | History | Literature | Mathematics | Physics |
+--------------+---------+-----------+---------+------------+-------------+---------+
| John Doe | Y | N | Y | N | Y | N |
+--------------+---------+-----------+---------+------------+-------------+---------+
| Robert Brown | N | N | N | Y | Y | Y |
+--------------+---------+-----------+---------+------------+-------------+---------+
| Charlie Cox | N | Y | N | Y | N | N |
+--------------+---------+-----------+---------+------------+-------------+---------+
随着更多的主题添加到数据库中,包含主题的列可能会增长得更多。根据我的要求,有一些关于pivot的建议,但我对此并不熟悉。
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