I would like to create a "count" or "order" field that would auto-increment, but restart after every change in a different field? In the table below, the "Order" field would restart at "1" every time there was a change in the "Meal" field. Thanks.
Meal | Time | RowNumb |
---|---|---|
Lunch | 10:30 | 1 |
Lunch | 11:00 | 2 |
Lunch | 11:30 | 3 |
Dinner | 4:30 | 1 |
Dinner | 5:00 | 2 |
Dinner | 5:30 | 3 |
Dinner | 6:00 | 4 |
I tried this:
SELECT
t1.meal,
COUNT(t2.meal) + 1 AS RowNumb
FROM CTE t1
JOIN CTE t2 ON t2.time < t1.time OR (t2.time = t1.time AND t2.meal <> t1.meal)
GROUP BY
t1.time,
t1.meal
ORDER BY
t1.time;
But I am getting this:
Meal | Time | RowNumb |
---|---|---|
Lunch | 10:30 | 1 |
Lunch | 11:00 | 2 |
Lunch | 11:30 | 3 |
Dinner | 4:30 | 4 |
Dinner | 5:00 | 5 |
Dinner | 5:30 | 6 |
Dinner | 6:00 | 7 |
Use a subquery to count the rows for the same meal and a time till then:
SELECT
t.meal,
t.time,
(
SELECT COUNT(*)
FROM mytable t2
WHERE t2.meal = t.meal
AND t2.time <= t.time
) AS rownumb
FROM mytable t
ORDER BY t.meal, t.time;