title: do database transactions prevent other users from interfering with it
body: <p>Suppose I do (note: the syntax below is probably not correct, but don't worry about it...it's just there to make a point)</p>
  
  <pre><code>Start Transaction
  INSERT INTO table (id, data) VALUES (100,20), (100,30);
  SELECT * FROM table WHERE id = 100;
  End Transaction
  </code></pre>
  
  <p>Hence the goal of the select is to get ALL info from the table that just got inserted by the preceding insert and ONLY by the preceding INSERT...</p>
  
  <p>Now suppose that during the execution, after the INSERT got executed, some other user also performs an INSERT with id = 100...</p>
  
  <p>Will the SELECT statement in the next step of the transaction also get the row inserted by the executed INSERT by the other user or will it just get the two rows inserted by the preceding INSERT within the transaction?</p>
  
  <p>Btw, I'm using MySQL so please tailor your answer to MySQL </p>