title: Update column with concat of second column and a variable
body: <p>I need to update column values (say column2) with concatenation of two string variables (say str1 &amp; str2) with another column (say column1). Final value which I need in column2 is str1 as prefix and str2 as suffix to column1 value. </p>
  
  <p>One way which can be done is with a dummy third column and a total of 4 update queries.</p>
  
  <pre><code>update table set column3 = str1;
  update table set column2 = concat(column3, column1);
  update table set column3 = str2;
  update table set column2 = concat(column2, column3);
  </code></pre>
  
  <p>But I want to reduce that to a single update without using a dummy column, like below - </p>
  
  <pre><code>update table set column2 = concat($str1, column1, $str2);
  </code></pre>
  
  <p>I need help in the concat part of the above query.</p>