MySQL Skip columns on condition - php

Question

I have the following table:
id speed date
1 0 01/01/2015
2 0 01/01/2015
3 0 01/01/2015
4 0 01/01/2015
5 0 01/01/2015
6 0 01/01/2015
7 25 01/01/2015
8 78 01/01/2015
9 13 01/01/2015
10 45 01/01/2015
11 0 01/01/2015
12 80 01/01/2015
13 86 01/01/2015
14 10 01/01/2015
15 0 01/01/2015
16 0 01/01/2015
17 0 01/01/2015
18 0 01/01/2015
This is just a small part of the table, it has many dates. Each new date starts and ends with an unknown amount of zeros. And I have to skip these zeros and get only what's between them. So I came up with the following solution:
Get the ID of the first row whose speed is positive (in our table it's id number 4).
Get the ID of the last row whose speed is positive (in our table it's id number 12).
Get lines between these two IDs (4 and 12).
I get the id of the first row whose speed is positive:
$q1=$conn->prepare("SELECT * FROM tableX WHERE speed > 0 order by date asc LIMIT 1");
$q1->execute();
$r1=$q1->fetch();
$first_id = $r1['id'];
And then get the id of the last row whose speed is positive:
$q2=$conn->prepare("SELECT * FROM tableX WHERE speed > 0 order by date desc LIMIT 1");
$q2->execute();
$r2=$q2->fetch();
$last_id = $r2['id'];
And then use those ids to get what I want:
$q3=$conn->prepare("SELECT * FROM tableX WHERE id between '$first_id' and '$last_id'");
$q3->execute();
while($r3=$q3->fetch(){}
Expected result:
id speed date
7 25 01/01/2015
8 78 01/01/2015
9 13 01/01/2015
10 45 01/01/2015
11 0 01/01/2015
12 80 01/01/2015
13 86 01/01/2015
14 10 01/01/2015
PS: row 11 is not a bug.
My code is actually working but I think this solution of mine is lame, so I am looking for an improvement, kind of all these three queries in one!

Answer 1

I'm not sure if this is exactly what you want, but I think this will be equivalent to your whole code:
$q3=$conn->prepare("SELECT * FROM tableX WHERE speed > 0");
$q3->execute();
while($r3=$q3->fetch(){}