MacLochlainns Weblog

UPDATE member m
SET    member_type =
 (SELECT common_lookup_id
  FROM   common_lookup
  WHERE  common_lookup_table = 'MEMBER'
  AND    common_lookup_column = 'MEMBER_TYPE'           
  AND    common_lookup_type =
          (SELECT  dt.member_type
           FROM   (SELECT   c.member_id
                   ,        CASE
                              WHEN COUNT(c.member_id) > 1 THEN 'GROUP'
                              ELSE 'INDIVIDUAL'
                            END AS member_type
                   FROM     contact c
                   GROUP BY c.member_id) dt
           WHERE   dt.member_id = m.member_id));

CREATE OR REPLACE FUNCTION get_member_type
(pv_member_id NUMBER) RETURN NUMBER IS
 
  -- Define a collection of strings.
  TYPE type_options IS TABLE OF VARCHAR2(10);
 
  -- Declare local variables.
  lv_dependent NUMBER := 1;
  lv_return_id NUMBER;
 
  -- Declare a local variable of the collection.
  lv_member_type TYPE_OPTIONS := type_options('INDIVIDUAL','GROUP');
 
  -- Define a dynamic cursor to count the number of foreign key values. 
  CURSOR count_contact (cv_member_id NUMBER) IS
    SELECT COUNT(c.member_id)
    FROM   contact c
    WHERE  c.member_id = cv_member_id;
 
  -- Define a dynamic cursor to find a key for an individual or group member type.    
  CURSOR get_lookup_id (cv_type VARCHAR2) IS
    SELECT common_lookup_id
    FROM   common_lookup
    WHERE  common_lookup_context = 'MEMBER'
    AND    common_lookup_type = cv_type;
 
BEGIN
 
  -- Get the number of foreign key values for a contact.
  OPEN  count_contact(pv_member_id);
  FETCH count_contact
  INTO  lv_dependent;
  CLOSE count_contact;
 
  -- Open the dynamic cursor with the required value.  
  IF lv_dependent = 1 THEN
    OPEN get_lookup_id(lv_member_type(1));
  ELSE
    OPEN get_lookup_id(lv_member_type(2));
  END IF;
 
  -- Get the correct surrogate primary key value.
  FETCH get_lookup_id
  INTO  lv_return_id;
  CLOSE get_lookup_id;
 
  -- Return the correct primary key for use as a foreign key.
  RETURN lv_return_id;
END;
/

SELECT 'DROP FUNCTION IF EXISTS get_member_type' AS "Statement";
DROP FUNCTION IF EXISTS get_member_type;
 
SELECT 'DELIMITER $$' AS "Statement";
DELIMITER $$
 
SELECT 'CREATE FUNCTION get_member_type' AS "Statement"$$
CREATE FUNCTION get_member_type(pv_member_id INT) RETURNS INT 
BEGIN
 
  /* Define three local variables. */
  DECLARE lv_contact_number  INT;
  DECLARE lv_member_type     CHAR(30);
  DECLARE lv_return_value    INT;
 
  /* Define a dynamic cursor to count the number of foreign key values. */  
  DECLARE contact_cursor CURSOR FOR
    SELECT COUNT(c.member_id)
    FROM   contact c
    WHERE  c.member_id = pv_member_id;
 
  /* Define a dynamic cursor to find a key for an individual or group member type. */
  DECLARE common_lookup_cursor CURSOR FOR
    SELECT common_lookup_id
    FROM   common_lookup
    WHERE  common_lookup_table = 'MEMBER'
    AND    common_lookup_column = 'MEMBER_TYPE'           
    AND    common_lookup_type = lv_member_type;
 
  /* Get the number of foreign key values for a contact. */    
  OPEN  contact_cursor;
  FETCH contact_cursor
  INTO  lv_contact_number;
  CLOSE contact_cursor;
 
  /* Assign group membership when more than one foreign key value is found; and
     assign individual membership when only one foreign key value is found. */  
  IF lv_contact_number > 1 THEN
    SET lv_member_type = 'GROUP';
  ELSE
    SET lv_member_type = 'INDIVIDUAL';
  END IF;
 
  /* Get the correct surrogate primary key value. */  
  OPEN  common_lookup_cursor;
  FETCH common_lookup_cursor
  INTO  lv_return_value;
  CLOSE common_lookup_cursor;
 
  /* Return the correct primary key for use as a foreign key. */  
  RETURN lv_return_value;
END;
$$
 
SELECT 'DELIMITER $$' AS "Statement"$$
DELIMITER ;

SELECT   m.member_id
,        dt.quantity
,        m.member_type
,        cl.common_lookup_type
FROM     member m JOIN (SELECT   member_id
                        ,        COUNT(c.member_id) AS quantity
                        FROM     contact c
                        GROUP BY c.member_id) dt
ON       m.member_id = dt.member_id JOIN common_lookup cl
ON       m.member_type = cl.common_lookup_id
ORDER BY m.member_id;