title: Multi-row insert with pg-promise
body: <p>I would like to insert multiple rows with a single <code>INSERT</code> query, for example:</p>
  
  <pre><code>INSERT INTO tmp(col_a,col_b) VALUES('a1','b1'),('a2','b2')...
  </code></pre>
  
  <p>Is there a way to do this easily, preferably for an array of objects like these: </p>
  
  <pre><code>[{col_a:'a1',col_b:'b1'},{col_a:'a2',col_b:'b2'}]
  </code></pre>
  
  <p>I might end up with 500 records in one chunk, so running multiple queries would be undesirable.</p>
  
  <p>So far I have been able to do it for a single object only:</p>
  
  <pre><code>INSERT INTO tmp(col_a,col_b) VALUES(${col_a},${col_b})
  </code></pre>
  
  <p>As a side question: Are insertions using <code>${}</code> notation protected against SQL injections?</p>