title: How to merge multiple rows value in one column/row in BigQuery
body: <p>I have sample data below, I like to merge all the <strong>biggest_win</strong> and <strong>multiplier</strong> in one column for player 1083987121 !</p>
  
  <pre><code>select * from player;
  
  player_key, country, biggest_win, multiplier, date
  1083987121, USD, 490.2, 163.4, 2020-03-17
  1083987121, USD, 256.0, 128.0, 2020-03-17
  1083987121, USD, 210.0, 70.0, 2020-03-17
  </code></pre>
  
  <p>What I'm expecting after merge</p>
  
  <pre><code>1083987121, USD, 490.2#256.0#256.0 163.4#128.0#70.0, 2020-03-17
  1083987121, USD, 490.2#256.0#256.0 163.4#128.0#70.0, 2020-03-17
  1083987121, USD, 490.2#256.0#256.0 163.4#128.0#70.0, 2020-03-17
  </code></pre>
  
  <p>Does anyone have a good solution for this? I have tried the XML function seems it doesn't work on BigQuery </p>