title: get ALL last level children (leafs) from a node (hierarhical queries Oracle 11G)
body: <p>I am trying and searching the way to <strong>get ALL last level children (leafs) from a node</strong>, in a hierchical query in Oracle 11g database. </p>
  
  <p>I have 2 tables: "Nodes" (A list of all nodes with their respective value), and "Relation" which specify father-child relation:</p>
  
  <hr>
  
  <h2>--NODES--</h2>
  
  <pre><code> ID_NODE    -      VALUE
  1       3
  2       6
  3       9
  4       2
  5       4
  6       5
  7       2
  8       7
  9       8
  10      1
  </code></pre>
  
  <hr>
  
  <h2>--RELATION--</h2>
  
  <pre><code>ID_FATHER    -   ID_CHILD
  1       2
  1       3
  1       4
  2       5
  2       6
  4       7
  5       8
  5       9
  7       10  
  </code></pre>
  
  <p>I have read about CONNECT_BY_ISLEAF which returns 1 if it is a leaf, but I cannot query CONNECT_BY_ISLEAF like the Oracle example, and I don´t get any result. Even though I don´t know exactly how to make the query exactly with this function (Using case condition for example?)</p>
  
  <p>Thank you too much!</p>