sys_connect_by_path : Hierarchical Queries « Query Select « Oracle PL/SQL Tutorial






  1. Oracle PL/SQL Tutorial
  2. Query Select
  3. Hierarchical Queries
SQL>
SQL> create table emp
  2  ( empno      NUMBER(4)    constraint E_PK primary key
  3  , ename      VARCHAR2(8)
  4  , init       VARCHAR2(5)
  5  , job        VARCHAR2(8)
  6  , mgr        NUMBER(4)
  7  , bdate      DATE
  8  , sal        NUMBER(6,2)
  9  , comm       NUMBER(6,2)
 10  , deptno     NUMBER(2)    default 10
 11  ) ;

Table created.

SQL> insert into emp values(1,'Tom','N',   'TRAINER', 13,date '1965-12-17',  800 , NULL,  20);

1 row created.

SQL> insert into emp values(2,'Jack','JAM', 'Tester',6,date '1961-02-20',  1600, 300,   30);

1 row created.

SQL> insert into emp values(3,'Wil','TF' ,  'Tester',6,date '1962-02-22',  1250, 500,   30);

1 row created.

SQL> insert into emp values(4,'Jane','JM',  'Designer', 9,date '1967-04-02',  2975, NULL,  20);

1 row created.

SQL> insert into emp values(5,'Mary','P',  'Tester',6,date '1956-09-28',  1250, 1400,  30);

1 row created.

SQL> insert into emp values(6,'Black','R',   'Designer', 9,date '1963-11-01',  2850, NULL,  30);

1 row created.

SQL> insert into emp values(7,'Chris','AB',  'Designer', 9,date '1965-06-09',  2450, NULL,  10);

1 row created.

SQL> insert into emp values(8,'Smart','SCJ', 'TRAINER', 4,date '1959-11-26',  3000, NULL,  20);

1 row created.

SQL> insert into emp values(9,'Peter','CC',   'Designer',NULL,date '1952-11-17',  5000, NULL,  10);

1 row created.

SQL> insert into emp values(10,'Take','JJ', 'Tester',6,date '1968-09-28',  1500, 0,     30);

1 row created.

SQL> insert into emp values(11,'Ana','AA',  'TRAINER', 8,date '1966-12-30',  1100, NULL,  20);

1 row created.

SQL> insert into emp values(12,'Jane','R',   'Manager',   6,date '1969-12-03',  800 , NULL,  30);

1 row created.

SQL> insert into emp values(13,'Fake','MG',   'TRAINER', 4,date '1959-02-13',  3000, NULL,  20);

1 row created.

SQL> insert into emp values(14,'Mike','TJA','Manager',   7,date '1962-01-23',  1300, NULL,  10);

1 row created.

SQL>
SQL>
SQL> select ename
  2  ,      sys_connect_by_path(ename,'|') as path
  3  from   emp
  4         start with mgr is null
  5         connect by prior empno = mgr
  6  order  siblings by ename;

ENAME
--------
PATH
--------------------------------------------------------------------------------
Peter
|Peter

Black
|Peter|Black

Jack
|Peter|Black|Jack

Jane
|Peter|Black|Jane

Mary
|Peter|Black|Mary

Take
|Peter|Black|Take

ENAME
--------
PATH
--------------------------------------------------------------------------------

Wil
|Peter|Black|Wil

Chris
|Peter|Chris

Mike
|Peter|Chris|Mike

Jane
|Peter|Jane

Fake
|Peter|Jane|Fake

Tom

ENAME
--------
PATH
--------------------------------------------------------------------------------
|Peter|Jane|Fake|Tom

Smart
|Peter|Jane|Smart

Ana
|Peter|Jane|Smart|Ana


14 rows selected.

SQL> /

ENAME
--------
PATH
--------------------------------------------------------------------------------
Peter
|Peter

Black
|Peter|Black

Jack
|Peter|Black|Jack

Jane
|Peter|Black|Jane

Mary
|Peter|Black|Mary

Take
|Peter|Black|Take

ENAME
--------
PATH
--------------------------------------------------------------------------------

Wil
|Peter|Black|Wil

Chris
|Peter|Chris

Mike
|Peter|Chris|Mike

Jane
|Peter|Jane

Fake
|Peter|Jane|Fake

Tom

ENAME
--------
PATH
--------------------------------------------------------------------------------
|Peter|Jane|Fake|Tom

Smart
|Peter|Jane|Smart

Ana
|Peter|Jane|Smart|Ana


14 rows selected.

SQL>
SQL>
SQL> drop table emp;

Table dropped.

SQL>








2.40.Hierarchical Queries
2.40.1.Hierarchical Queries
2.40.2.Using the CONNECT BY and START WITH Clauses
2.40.3.Formatting the Results from a Hierarchical Query
2.40.4.Starting at a node other than the root
2.40.5.Traversing Upward Through the Tree
2.40.6.Eliminating Nodes and Branches from a Hierarchical Query
2.40.7.Add where clause to a Hierarchical Query
2.40.8.employee tree: who is my manager
2.40.9.Output full path of hierarchy
2.40.10.sys_connect_by_path
2.40.11.pseudocolumn LEVEL and an example of using the levels.
2.40.12.pseudocolumn LEVEL and an example of using the levels with an update.