title: START WITH and CONNECT BY in Oracle SQL
body: <p>I have table as below </p>
  
  <p><strong>ACCOUNT</strong>  </p>
  
  <pre><code>CUSTOMER_ID   PAYING_ACCOUNT_ID   PARENT_ACCOUNT_ID     ACCOUNT_ID   COMPANY_ID 
  24669         24669               24669                 24669        0 
  24671         24671               24669                 24671        0  
  24670         24670               24669                 24670        0 
  3385217       3385217             24670                 3385217      0 
  158           158                 158                   158          0
  159           159                 158                   159          0
  160           160                 159                   160          0
  161           161                 160                   161          0 
  162           162                 160                   162          0
  180           180                 180                   180          0 
  </code></pre>
  
  <p>This is the DDL</p>
  
  <pre><code>CREATE TABLE "SYSTEM"."ACCOUNT"
  ("CUSTOMER_ID"       NUMBER(20,0) NOT NULL ENABLE,
  "PAYING_ACCOUNT_ID" NUMBER(20,0),
  "PARENT_ACCOUNT_ID" NUMBER(20,0),
  "ACCOUNT_ID"        NUMBER,
  "COMPANY_ID"        NUMBER)
  </code></pre>
  
  <p>This is my query</p>
  
  <pre><code>   select  lpad(' ', 2*level) || A.ACCOUNT_ID AS LEVEL_LABEL, 
             LEVEL, 
            A.* 
        from ACCOUNT A 
  start with PARENT_ACCOUNT_ID IN 
                         (select PARENT_ACCOUNT_ID 
                            from ACCOUNT 
                           where ACCOUNT_ID IN 
                                          (select PARENT_ACCOUNT_ID
                                             from ACCOUNT 
                                            where parent_account_id != account_id)
                                              and ACCOUNT_ID = PARENT_ACCOUNT_ID) 
     CONNECT BY NOCYCLE  PRIOR A.ACCOUNT_ID = A.PARENT_ACCOUNT_ID;
  </code></pre>
  
  <p>The main objective of the query is to select data that has a hierarchical relationship, which are PARENT_ACCOUNT_ID &amp; ACCOUNT_ID, however i got a duplicate data returned by the query </p>
  
  <p>Any advice much appreciated. Thanks</p>