title: Mysql select recursive get all child with multiple level
body: <p>i have a table </p>
  
  <pre><code> CREATE TABLE IF NOT EXISTS `Folder` (
      `idFolder` INT(11) NOT NULL AUTO_INCREMENT,
      `FolderName` VARCHAR(150) NOT NULL,
      `idFolderParent` INT(11) NULL,
      PRIMARY KEY (`idFolder`),
      CONSTRAINT `fk_1`
      FOREIGN KEY (`idFolderParent`)
      REFERENCES `Folder` (`idFolder`)
  )
  </code></pre>
  
  <p>i fill this table by</p>
  
  <pre><code>idFolder , FolderName , idFolderParent
     1           ADoc           Null  
     2           ADoc1           1  
     3           ADoc2           2
     4           ADoc3           3
     5           ADoc4           4
     6           ADoc5           5
     7           ADoc6           4
  </code></pre>
  
  <p>when select a folder with idFolder=1, it should be return all child for this folder and subchild folder(2, 3, 4, 5 ,6 ,7)</p>
  
  <p>When i select a folder id = 4 ==> (5,7, 6)</p>
  
  <p>When i select a folder id = 3 ==> (4, 5,6, 7)</p>
  
  <p>How to do that with one query?</p>
  
  <p>Thx</p>