title: SQL DELETE with JOIN another table on multiple conditions for WHERE NULL
body: <p>I have to delete rows from slaveTable that have no more relation with masterTable table (dead relations, removed from masterTable).</p>
  
  <p>I came up with the statement:</p>
  
  <pre><code>DELETE
  FROM   slaveTable AS s
  LEFT JOIN 
         masterTable AS m 
  ON   ( s.key1 = m.key1
  AND    s.key2 = m.key2 )
  WHERE  m.key1 IS NULL
  </code></pre>
  
  <p><a href="https://stackoverflow.com/questions/1980738/sql-delete-with-join-another-table-for-where-condition">SQL DELETE with JOIN another table for WHERE condition</a>
  shows this way as a solution... but won't work for me. 
  Because of my lack of reputation I can't answer there.</p>