sql - количество двух столбцов

Question

Я положил в базу данных много строк, и у меня есть это:

+----+---------------------+-------------+----------------+-----------+
| ID | time                | os_name     | program        | last_line |
+----+---------------------+-------------+----------------+-----------+
| 14 | 2019-01-04 14:00:00 | titi        | roro           | 109       |
| 15 | 2019-01-04 14:00:00 | titi        | roro           | 109       |
| 16 | 2019-01-04 14:00:00 | gege        | fefe           | 109       | 

я хочу:

+---------------------+-------------------------+-------------+-----------+-----------+
| time                | nb_os_name_program      | os_name     | program   | last_line |
+---------------------+-------------------------+-------------+-----------+-----------+
| 2019-01-04 14:00:00 |                      2  | titi        | roro      | 109       |
| 2019-01-04 14:00:00 |                      1  | gege        | fefe      | 109       | 

Answer 1

Простой GROUP BY с агрегацией поможет вам:

SELECT time, os_name, count(*) as nb_os_name, program, lastline, 
FROM table t
GROUP BY time, os_name, program, lastline