title: Query Two Tables from different Schema but Same Database
body: <p>First, I saw a similar question asked here:<a href="https://stackoverflow.com/questions/980620/query-two-tables-from-different-schema">Query two tables from different schema</a>, but the answer did not work for me.</p>
  
  <p>My Situation: same table, different schemas, same database (oracle by the way). I am trying to find all rows in one schema.table that are not in the other. I have the following query:</p>
  
  <pre><code>select S1.ID
  FROM SCHEMA1.DATABASE_UPDATE S1, 
  SCHEMA2.DATABASE_UPDATE S2
  WHERE
  S1.ID != S2.ID
  </code></pre>
  
  <p>I get thousands of repeating entries. So obviously, this is wrong. There are 448 rows in S1 and 439 in S2. There should be only 9 unique rows. What am I doing wrong? thanks!</p>
  
  <p>By the way, I am doing this from sqlDeveloper.</p>