title: Retrieve all ids without iterating?
body: <p>I have one table with almost 2 million records on my SQLite database, some records have null birthday and I would like to fix with data from antoher database since the ids are the same on both I can reference it for this update.</p>
  
  <p>However I am having an issue for reading and I believe I will have antoher for updating it.</p>
  
  <p>Reading issue, is there a way to get all the ids from the result without having to read 1 by 1 ? </p>
  
  <p>Query being executed is (birthday is indexed):</p>
  
  <pre><code>SELECT id FROM personal WHERE birthday IS NULL OR birthday = ''
  </code></pre>
  
  <p>Currently I do this to retrieve all ids (which take something like 3 minutes for the first 300k records and then increase to something like 9 minutes for 250k records and keep growing the delay):</p>
  
  <pre><code>while (reader.Read())
  {
      ids.Add(reader.GetInt32(0));
  }
  </code></pre>
  
  <p>After I will reuse the ids list to execute an update to each record with the correct birthday which I assume I will run into the same issue, it will take a long time to get it done by inserting 1 by 1, which bring us to what I believe that will be the second issue.</p>
  
  <p>Is there a fast way to update all the records with the needed data ?</p>
  
  <p><strong>NOTE: the birthdays I will read for updating the SQLITE will come from a remote MySQL server and as such I cannot link the 2 in 1 query like update select etc.</strong></p>
  
  <p>Table format is:</p>
  
  <pre><code>id
  first_name
  last_name
  birthday
  email
  status
  </code></pre>
  
  <p><strong>When I run the same query on SQLite Admin it takes 2371ms to spit all the data, so I assume I must be reading it wrong or reading 1 by 1 must be hurting it really bad.</strong></p>