Method Function not getting values from single row (Nested table) - sql

Question

Hi I've asked a question related to this already but have a second question. I commented that I made a nested table of the teams that played rather than separate rows for each team and score.
I want to run the Method for a particular GameId rather than all the rows in the table.. I've included my Game_Type Object this time though I didn't think it was necessary last time.
CREATE TYPE Game_Type AS OBJECT
(GameId NUMBER)
/
CREATE TABLE Game_Table of Game_Type
/
INSERT INTO Game_Table
VALUES (1)
/
INSERT INTO Game_Table
VALUES (2)
/
CREATE TYPE Team_Type AS OBJECT
(TeamPlayed VARCHAR2(30),
TeamScore NUMBER(1))
/
CREATE TYPE TeamsPlayed_Table as TABLE OF Team_Type
/
CREATE OR REPLACE TYPE After_Team AS OBJECT
(GameRef REF Game_Type,
GamePlayed Teamsplayed_Table,
MAP MEMBER FUNCTION team_rating RETURN NUMBER)
/
CREATE TABLE Team_Table of After_Team NESTED TABLE GamePlayed STORE AS
GamePlayed_Nested
/
CREATE OR REPLACE TYPE BODY After_Team
AS
MAP MEMBER FUNCTION team_rating
RETURN NUMBER
IS
avg_score NUMBER;
BEGIN
SELECT AVG(c.TeamScore)
INTO avg_score
FROM Team_Table d, table(d.GamePlayed) c;
RETURN avg_score;
END;
END;
/
INSERT INTO Team_Table
VALUES((SELECT REF(a) FROM Game_Table a WHERE a.gameid = 1),
(TeamsPlayed_Table(Team_Type('Team A', 1), Team_Type('Team B', 3))))
/
INSERT INTO Team_Table
VALUES((SELECT REF(a) FROM Game_Table a WHERE a.gameid = 2),
(TeamsPlayed_Table(Team_Type('Team C', 5), Team_Type('Team D', 9))))
/
Now when I execute my method:
SELECT t.team_rating()
from Team_Table t
where t.GameRef.GameId = 1
It's returning the average for all the values as opposed to just Game 1..

Answer 1

Assuming you want to get the average of the TeamScore in the GamePlayed collection for that team then you can do it in pure PL/SQL (without a context-switch into the SQL scope):
CREATE OR REPLACE TYPE BODY After_Team
AS
MAP MEMBER FUNCTION team_rating
RETURN NUMBER
IS
avg_score NUMBER := 0;
j INTEGER := 0;
BEGIN
FOR i IN 1 .. self.GamePlayed.COUNT LOOP
IF self.GamePlayed(i) IS NOT NULL AND self.GamePlayed(i).TeamScore IS NOT NULL THEN
avg_score := avg_score + self.GamePlayed(i).TeamScore;
j := j + 1;
END IF;
END LOOP;
IF j > 0 THEN
RETURN avg_score / j;
ELSE
RETURN NULL;
END IF;
END;
END;
/
SQLFIDDLE
otherwise, you could use:
CREATE OR REPLACE TYPE BODY After_Team
AS
MAP MEMBER FUNCTION team_rating
RETURN NUMBER
IS
avg_score NUMBER;
BEGIN
SELECT avg( TeamScore )
INTO avg_score
FROM TABLE( self.GamePlayed );
RETURN avg_score;
END;
END;
/
SQLFIDDLE