Mark Phillips wrote:
Flights
+-----------+----------+----------+
| flight_id | data1_id | data2_id |
+-----------+----------+----------+
| 1 | 1 | 1 |
| 2 | 1 | 3 |
| 3 | 1 | 1 |
| 4 | 2 | 2 |
| 5 | 2 | 3 |
| 6 | 1 | 1 |
| 7 | 1 | 1 |
| 8 | 4 | 4 |
| 9 | 1 | 2 |
| 10 | 1 | 2 |
| 11 | 1 | 1 |
+-----------+----------+----------+
The data1_id and data2_id are indexes for the data recorded for that flight.
I want to summarize the data. One such summary is to count the number of
different data1_id's and data2_id's. For example:
Flight Result Summary
index: 1 2 3 4
data1_id 8 2 0 1
data2_id 5 3 2 1
select
sum(if(data1_id =1,1, 0)) as data1_id_1, sum(if(data1_id =2, 1,
0)) as data1_id_2, etc , etc
sum(if(data2_id =1,1, 0)) as data2_id_1, sum(if(data2_id =2, 1,
0)) as data2_id_2 etc, etc
from flights
add composite indexes if required for speed.
Nigel
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
