Bootstrap 3. Three-column war?

Question

css

Please help me figure out the columns, I can’t do it like in the picture, I’ve been trying for an hour, all the time the middle column, then more or less than the rest. How to make sure that the columns with images inside are located exactly in such a tile?
Image

<div class="container">
  <div class="row">
    <div class="left-col hidden-xs col-sm-4">
      <div class="thumbnail">
        <img src="images/Pic1.jpg" alt="...">
      </div>
      <div class="thumbnail">
        <img src="images/Pic2.jpg" alt="...">
      </div>
    </div>
    <div class="middle-col col-sm-4">
      <div class="thumbnail">
        <img src="images/Pic3.jpg" alt="...">
      </div>
      <div class="thumbnail">
        <img src="images/Pic4.jpg" alt="...">
      </div>
      <div class="thumbnail">
        <img src="images/Pic5.jpg" alt="...">
      </div>
    </div>
    <div class="right-col hidden-xs col-sm-4">
      <div class="thumbnail">
        <img src="images/Pic6.jpg" alt="...">
      </div>
      <div class="thumbnail">
        <img src="images/Pic7.jpg" alt="...">
      </div>
    </div>
  </div>
</div>

Answer 1

codepen.io/Lumore/pen/WpNJyz

Answer 2

bootstrap+masonry

Answer 3

It is not possible to make a squirrel out of a hedgehog so that it meows -)
What is the essence of this action? Change primary key type?
Universal method:
- creating a new field
- filling in a new field
- transferring constraints
- deleting an old field
- renaming a new field
That is, in this case
- create a new field id2 int
- fill it with values ​​- apparently implying uniqueness (you can either identity or arithmetic)
- kill id
- modify and rename id2 to id (primary key)
add a new one