title: Update multiple columns in a TABLE from another TABLE (Oracle)
body: <p>I would like to update multiple columns in one table based on values in another.</p>
  
  <p>I <em>think</em> I know how to write an update statement in T-SQL that does what I want (haven't tested the below). Problem is I'm trying to translate this for an Oracle database. Does anyone know how to do the following in Oracle:</p>
  
  <pre><code>UPDATE oldauth SET
    AUTHUNIQUENAME=newauth.AUTHUNIQUENAME
    DESCRIPTION=newauth.DESCRIPTION
    MAPPINGAUTHNAME=newauth.MAPPINGAUTHNAME
  FROM
   (SELECT * FROM USERS1 WHERE AUTHSOURCEID=100) oldauth
  LEFT JOIN
   (SELECT * FROM USERS2 WHERE AUTHSOURCEID=200) newauth
  ON 
  oldauth.AUTHUSERNAME=newauth.AUTHUSERNAME;
  </code></pre>