1
我有兩個表,我想獲得按標記分組的任務的日誌記錄總和,大多數時間子任務具有與父母,但在某些情況下,他們不。如果從子任務標記爲空,從父任務繼承標記
如何獲取按標記分組的記錄分鐘總數,包括子任務,因此如果他們沒有標記,他們會繼承父標記。
任務
+-----+-----------+------+-------+------------+
| id | parent-id | name | tag | is-subtask |
+-----+-----------+------+-------+------------+
| 001 | | a | sales | 0 |
| 002 | 001 | b | sales | 1 |
| 003 | 001 | c | | 1 |
| 004 | | d | store | 0 |
+-----+-----------+------+-------+------------+
次
+-----+---------+-------------+----------------+
| id | task-id | description | logged-minutes |
+-----+---------+-------------+----------------+
| 991 | 001 | Time for a | 15 |
| 992 | 002 | Time for ab | 60 |
| 993 | 002 | Time for ab | 75 |
| 994 | 003 | Time for ac | 35 |
| 995 | 004 | Time for d | 20 |
+-----+---------+-------------+----------------+