title: String concatenation operator in Oracle, Postgres and SQL Server
body: <p>Is there a way to have a common operator for concatenation in Oracle, Postgres and SQL Server.</p>
  <p>In Oracle and Postgres we use <code>||</code> and SQL Server uses <code>+</code>.</p>
  <p>I've solved the problem in Postgres by adding the custom operator <code>+</code> to support string concatenation.</p>
  <p>Is there a way to add the same operator in Oracle to support string concatenation using the <code>+</code> operator.</p>