title: In Oracle, why is '' = '' false?
body: <p>This question comes from my previous <a href="https://stackoverflow.com/questions/10936176/searching-for-text-in-a-database-with-entity-framework">post</a>.</p>
  
  <p>I'm curious as to why:</p>
  
  <pre><code>select * from TPM_USER where '' = ''
  </code></pre>
  
  <p>Returns zero rows, however:</p>
  
  <pre><code>select * from TPM_USER where 1 = 1
  </code></pre>
  
  <p>Returns every row in the table.  Is this per SQL standard, or is this Oracle specific?</p>
  
  <p>Oracle <a href="http://sqlfiddle.com/#!4/74757/5" rel="nofollow noreferrer">SQL Fiddle</a>.</p>
  
  <p>The following work as expected:</p>
  
  <p>PostgreSQL <a href="http://sqlfiddle.com/#!1/66640/1" rel="nofollow noreferrer">SQL Fiddle</a></p>
  
  <p>SQL Server <a href="http://sqlfiddle.com/#!3/66640/1" rel="nofollow noreferrer">SQL Fiddle</a></p>
  
  <p>mySQL <a href="http://sqlfiddle.com/#!2/66640/1" rel="nofollow noreferrer">SQL Fiddle</a></p>