MySQL: Tree-Hierarchical query

SUB-TREE WITHIN A TREE in MySQL

Database COMPANY

Table: Employee

A self relationship of kind (SuperVisor (1)- SuperVisee (∞) )

CREATE TABLE IF NOT EXISTS `Employee` (
`SSN` varchar(64) NOT NULL,
`Name` varchar(64) DEFAULT NULL,
`Designation` varchar(128) NOT NULL,
`MSSN` varchar(64) NOT NULL,
PRIMARY KEY (`SSN`),
CONSTRAINT `FK_Manager_Employee`
FOREIGN KEY (`MSSN`) REFERENCES Employee(SSN)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSERT INTO Employee VALUES
("1", "A", "OWNER",  "1"),

("2", "B", "BOSS",   "1"), # Employees under OWNER
("3", "F", "BOSS",   "1"),

("4", "C", "BOSS",   "2"), # Employees under B
("5", "H", "BOSS",   "2"),
("6", "L", "WORKER", "2"),
("7", "I", "BOSS",   "2"),
# Remaining Leaf nodes
("8", "K", "WORKER", "3"), # Employee under F

("9", "J", "WORKER", "7"), # Employee under I

("10","G", "WORKER", "5"), # Employee under H

("11","D", "WORKER", "4"), # Employee under C
("12","E", "WORKER", "4")

A     <---ROOT-OWNER
/|\
/ A \
B     F
//| \    \
// |  \    K
/ | |   \
I  L H    C
/     |   / \
J     G  D   E

SELECT  SUPERVISOR.name AS SuperVisor,
GROUP_CONCAT(SUPERVISEE.name  ORDER BY SUPERVISEE.name ) AS SuperVisee,
COUNT(*)
FROM Employee AS SUPERVISOR
INNER JOIN Employee SUPERVISEE ON  SUPERVISOR.SSN = SUPERVISEE.MSSN
GROUP BY SuperVisor;

+------------+------------+----------+
| SuperVisor | SuperVisee | COUNT(*) |
+------------+------------+----------+
| A          | A,B,F      |        3 |
| B          | C,H,I,L    |        4 |
| C          | D,E        |        2 |
| F          | K          |        1 |
| H          | G          |        1 |
| I          | J          |        1 |
+------------+------------+----------+
6 rows in set (0.00 sec)

SUB-TREE

B

+------------+------------+----------+
| SuperVisor | SuperVisee | COUNT(*) |
+------------+------------+----------+
| B          | C,H,I,L    |        4 |
| C          | D,E        |        2 |
| H          | G          |        1 |
| I          | J          |        1 |
+------------+------------+----------+

share|improve this question

edited Dec 11 '12 at 9:28

asked Dec 6 '12 at 15:36 Grijesh Chauhan 2862413

migrated from stackoverflow.com Dec 8 '12 at 9:42

UPDATE 2012-12-11 12:11 EDT

DELIMITER $$

DROP FUNCTION IF EXISTS `cte_test`.`GetFamilyTree` $$
CREATE FUNCTION `cte_test`.`GetFamilyTree`(GivenName varchar(64))
RETURNS varchar(1024) CHARSET latin1
DETERMINISTIC
BEGIN

DECLARE rv,q,queue,queue_children,queue_names VARCHAR(1024);
DECLARE queue_length,pos INT;
DECLARE GivenSSN,front_ssn VARCHAR(64);

SET rv = '';

SELECT SSN INTO GivenSSN
FROM Employee
WHERE name = GivenName
AND Designation <> 'OWNER';
IF ISNULL(GivenSSN) THEN
RETURN ev;
END IF;

SET queue = GivenSSN;
SET queue_length = 1;

WHILE queue_length > 0 DO
IF queue_length = 1 THEN
SET front_ssn = queue;
SET queue = '';
ELSE
SET pos = LOCATE(',',queue);
SET front_ssn = LEFT(queue,pos - 1);
SET q = SUBSTR(queue,pos + 1);
SET queue = q;
END IF;
SET queue_length = queue_length - 1;
SELECT IFNULL(qc,'') INTO queue_children
FROM
(
SELECT GROUP_CONCAT(SSN) qc FROM Employee
WHERE MSSN = front_ssn AND Designation <> 'OWNER'
) A;
SELECT IFNULL(qc,'') INTO queue_names
FROM
(
SELECT GROUP_CONCAT(name) qc FROM Employee
WHERE MSSN = front_ssn AND Designation <> 'OWNER'
) A;
IF LENGTH(queue_children) = 0 THEN
IF LENGTH(queue) = 0 THEN
SET queue_length = 0;
END IF;
ELSE
IF LENGTH(rv) = 0 THEN
SET rv = queue_names;
ELSE
SET rv = CONCAT(rv,',',queue_names);
END IF;
IF LENGTH(queue) = 0 THEN
SET queue = queue_children;
ELSE
SET queue = CONCAT(queue,',',queue_children);
END IF;
SET queue_length = LENGTH(queue) - LENGTH(REPLACE(queue,',','')) + 1;
END IF;
END WHILE;

RETURN rv;

END $$

mysql> SELECT name,GetFamilyTree(name) FamilyTree
-> FROM Employee WHERE Designation <> 'OWNER';
+------+-----------------------+
| name | FamilyTree            |
+------+-----------------------+
| A    | B,F,C,H,L,I,K,D,E,G,J |
| G    |                       |
| D    |                       |
| E    |                       |
| B    | C,H,L,I,D,E,G,J       |
| F    | K                     |
| C    | D,E                   |
| H    | G                     |
| L    |                       |
| I    | J                     |
| K    |                       |
| J    |                       |
+------+-----------------------+
12 rows in set (0.36 sec)

mysql>

mysql> select * from Employee;
+-----+------+-------------+------+
| SSN | Name | Designation | MSSN |
+-----+------+-------------+------+
| 0   | A    | OWNER       | 0    |
| 1   | A    | BOSS        | 0    |
| 10  | G    | WORKER      | 5    |
| 11  | D    | WORKER      | 4    |
| 12  | E    | WORKER      | 4    |
| 2   | B    | BOSS        | 1    |
| 3   | F    | BOSS        | 1    |
| 4   | C    | BOSS        | 2    |
| 5   | H    | BOSS        | 2    |
| 6   | L    | WORKER      | 2    |
| 7   | I    | BOSS        | 2    |
| 8   | K    | WORKER      | 3    |
| 9   | J    | WORKER      | 7    |
+-----+------+-------------+------+
13 rows in set (0.00 sec)

mysql>

share|improve this answer

edited Dec 11 '12 at 17:11

answered Dec 10 '12 at 20:09 RolandoMySQLDBA 102k13131263