title: SELECT / GROUP BY - segments of time (10 seconds, 30 seconds, etc)
body: <p>I have a table (MySQL) that captures samples every n seconds.  The table has many columns, but all that matters for this is two: a time stamp (of type TIMESTAMP) and a count (of type INT).  </p>
  
  <p>What I would like to do, is get sums and averages of the count column over a range of times.  For instance, I have samples every 2 seconds recorded, but I would like the sum of the count column for all the samples in a 10 second or 30 second window for all samples.</p>
  
  <p>Here's an example of the data:</p>
  
  <pre>
  +---------------------+-----------------+
  | time_stamp          | count           |
  +---------------------+-----------------+
  | 2010-06-15 23:35:28 |               1 |
  | 2010-06-15 23:35:30 |               1 |
  | 2010-06-15 23:35:30 |               1 |
  | 2010-06-15 23:35:30 |             942 |
  | 2010-06-15 23:35:30 |             180 |
  | 2010-06-15 23:35:30 |               4 |
  | 2010-06-15 23:35:30 |              52 |
  | 2010-06-15 23:35:30 |              12 |
  | 2010-06-15 23:35:30 |               1 |
  | 2010-06-15 23:35:30 |               1 |
  | 2010-06-15 23:35:33 |            1468 |
  | 2010-06-15 23:35:33 |             247 |
  | 2010-06-15 23:35:33 |               1 |
  | 2010-06-15 23:35:33 |              81 |
  | 2010-06-15 23:35:33 |              16 |
  | 2010-06-15 23:35:35 |            1828 |
  | 2010-06-15 23:35:35 |             214 |
  | 2010-06-15 23:35:35 |              75 |
  | 2010-06-15 23:35:35 |               8 |
  | 2010-06-15 23:35:37 |            1799 |
  | 2010-06-15 23:35:37 |              24 |
  | 2010-06-15 23:35:37 |              11 |
  | 2010-06-15 23:35:37 |               2 |
  | 2010-06-15 23:35:40 |             575 |
  | 2010-06-15 23:35:40 |               1 |
  | 2010-06-17 10:39:35 |               2 |
  | 2010-06-17 10:39:35 |               2 |
  | 2010-06-17 10:39:35 |               1 |
  | 2010-06-17 10:39:35 |               2 |
  | 2010-06-17 10:39:35 |               1 |
  | 2010-06-17 10:39:40 |              35 |
  | 2010-06-17 10:39:40 |              19 |
  | 2010-06-17 10:39:40 |              37 |
  | 2010-06-17 10:39:42 |              64 |
  | 2010-06-17 10:39:42 |               3 |
  | 2010-06-17 10:39:42 |              31 |
  | 2010-06-17 10:39:42 |               7 |
  | 2010-06-17 10:39:42 |             246 |
  +---------------------+-----------------+
  </pre>
  
  <p>The output I would like (based on the data above) should look like this:</p>
  
  <pre>
  +---------------------+-----------------+
  | 2010-06-15 23:35:00 |               1 |  # This is the sum for the 00 - 30 seconds range
  | 2010-06-15 23:35:30 |            7544 |  # This is the sum for the 30 - 60 seconds range
  | 2010-06-17 10:39:35 |             450 |  # This is the sum for the 30 - 60 seconds range
  +---------------------+-----------------+
  </pre>
  
  <p>I have used GROUP BY to gather these numbers by the second, or by the minute, but I can't seem to figure out the syntax to get the sub-minute or range of seconds GROUP BY commands to work correctly.</p>
  
  <p>I am mostly going to be using this query to syphon data from this table to another table.</p>
  
  <p>Thanks!</p>