Modal Window, Get Row Value, Bootstrap Table

I have a question.

I have a table in which I show the ones of a client, of a table called Clients with fields: user_first, user_last, user_uid ...

Then I have a button with the symbol '#' that when pressed shows me a modal window with values of another table that have a relationship with this client, the other table is called FERTILIZERS.

Each client has that '#' button to show that data in the modal window.

How do I press it to detect the value of the row I press or the username ??

Currently I did it rude: "SELECT loan_id,loan_amount,loan_totalint FROM loans WHERE user_uid='Don mario'";

But how do I know how many users or names they will have as I do to identify the row?

Please help me?

my code is as follows:

       <?php
       $sql2= "SELECT loan_id,loan_amount,loan_totalint FROM loans WHERE 
       user_uid='Don mario'";


       $result2 = mysqli_query($connect, $sql2);

        ?>

        <?php

        echo '

               <!-- Modal -->
               <div id="myModal" class="modal fade" role="dialog">
               <div class="modal-dialog modal-lg">

               <!-- Modal content-->
               <div class="modal-content">
               <div class="modal-header">
               <button type="button" class="close" data- 
               dismiss="modal">&times;</button>
               <h4 class="modal-title">Loan Info</h4>
               </div>
               <div class="modal-body">

               <div class="container table-responsive">

               <table class="table table-hover">
               <thead>
               <tr>  
                 <th width="0.01%">Id</th>   
                 <th width="0.01%">Monto Actual</th>
                 <th width="0.01%">Total Interes</th>    

               </tr>
               </thead>';

               if(mysqli_num_rows($result2) > 0)  
               {  
               while($row = mysqli_fetch_array($result2))  
               {
               echo' <tbody>

              <tr>
              <td>'.$row["loan_id"].'</td> 

              <td class="loan_amount" data-id2="'.$row["loan_id"].'" 
              >'.$row["loan_amount"].'</td>

              <td class="loan_totalint" data- 
              id3="'.$row["loan_id"].'">'.$row["loan_totalint"].'</td>

              </tr>
              </tbody>';

              }
              echo '

             <tr>  
             <td></td>   
            <td id="loan_amount"></td>
            <td id="loan_totalint"></td>  

            </tr>';

            }

           echo '     

           </table>  
           </div> 


            </div>
             <div class="modal-footer">
             <button type="button" class="btn btn-default" data- 
             dismiss="modal">Close</button>
             </div>
            </div>

             </div>
             </div>  ';