我继承了我的怀疑是一些劣质的SQL表的设计,并作为SQL新手,我挣扎拿出一个查询的加入和连接的数据.
以下是包含数据的两个表:
user_space:
+----+---------+---------+---------+----------+----------+----------+
| id | space_1 | space_2 | space_3 | units_s1 | units_s2 | units_s3 |
+----+---------+---------+---------+----------+----------+----------+
| 1 | 128 | 128 | 6 | 3 | 3 | 4 |
| 2 | 1 | 128 | 2 | 4 | 3 | 4 |
| 3 | 100 | 100 | 100 | 3 | 3 | 3 |
+----+---------+---------+---------+----------+----------+----------+
space_units:
+------+--------------+
| type | description |
+------+--------------+
| 1 | KB |
| …