SQL & PL/SQL

Hi, everione,

I am having a big problem, trying to create datebase.
I have 3 tables: SUPERAVATAR, MASTERAVATAR, MEGAAVATAR.
- SuperAvatars are heroes in an online role playing gaming. They have an ID, ‘superavatarID’ which contain an UNIQUE NUMBER NOT NULL PRIMARY KEY to identify them.
A wisdom – ‘trickster’,’conjuror’,’magician’, etc..
A current owner… who is the user or player of the game and has that Super Avatar– we associate the link to USERID to know the person.
SuperAvatars can be fathers or mothers of Mega Avatars.
-MegaAvatars are the children of SuperAvatars…. They also have an ID UNIQUE NUMBER NOT NULL PRIMARY KEY to indentify them.
A magic power – it can be a ‘Leader’ or ‘Sheep’…
A ‘parent’ – parent is the number identifying to know to who Super Avatar belongs.
e.g.
SUPERAVAT WISD CURRENTOWNER FATHEROF MOTHEROF
1 Thick 3 1
2 Mentally Ch. 11 3
3 Smart 9 2
4 Genius 16 4
5 Thick 19



MEGAAVATARID MAGICPOWER PARENT
1 MAGICIAN 1
2 WIZARD 3
3 SORCERER 2
4 MAGICIAN 4

-We see that MEGAAVATAR 1 has a magic power as Magician and his father is ‘1’. ‘1’ identifies the SUPERAVATAR.
We see SUPERAVATARID…. who has the number ‘1’? the first in the row… who has wisdom – thick and he belongs to the USER with ID number 3.
-We see MEGAAVATARID… we choose the number 2…. His magic power is as WIZARD… and his father is the number 3.
We see SUPERAVATARID now… we look up the SuperavatarID 3…. We can see he has a wisdom – GENIUS… who belongs to the USERID 16 and he is father of MEGAAVATAR number 2.
The list can carry on and never stop.

I have this Problems:
We create in this example 3 tables: Users, SuperAvatar, MegaAvatar

SQL
CREATE TABLE users(userID NUMBER CONSTRAINT pk_user PRIMARY KEY,email VARCHAR2(50) NOT NULL UNIQUE,password VARCHAR2(15) NOT NULL UNIQUE,subscription CHAR(8) NOT NULL CHECK (subscription IN('ACTIVE' , 'INACTIVE' ) ) );

CREATE TABLE superavatar(superavatarID NUMBER CONSTRAINT pk_superavatar PRIMARY KEY, wisdom VARCHAR2(19) NOT NULL CHECK (wisdom IN ('THICK', 'MENTALLY CHALLENGED', 'AWAKE', 'SMART', 'GENIUS')), currentOwner NUMBER NOT NULL, fatherOf NUMBER,motherOf NUMBER);

CREATE TABLE megaavatar (megaavatarID NUMBER CONSTRAINT pk_megaavatar PRIMARY KEY, magicPower VARCHAR2(12) NOT NULL CHECK (magicPower IN('TRICKSTER','CONJUROR','MAGICIAN','WIZARD','SORCERER')), parent NUMBER);

Now, the 3 tables are created…..
What happen when we try to insert values to this table?
In this case we insert to User Table some examples:
INSERT INTO users VALUES('3','john@hotmail.com','great78','ACTIVE');
INSERT INTO users VALUES('9','chrisandsandra@gmail.com','chrisandra)','ACTIVE');
Now, we insert to SuperAvatar some examples;
INSERT INTO superavatar VALUES('1','THICK','3','1','');
INSERT INTO superavatar VALUES('3','SMART','9','3','');
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‘9’ is the UserID that we already insert to the User table
What’s the problem?
We have to insert manually the data from USERID to CURRENTOWNER as we didn’t match or link CURRENTOWNER from SUPERAVATAR Table to USERID from USER Table with a SQL CODE.
What happen if we have thousands of USERS that they register to this game…? We will never know to how belongs that SUPERAVATAR but if someone do it manually can spend a year.

I am trying to fix this problem …. I add in SUPERAVATAR TABLE ‘CHECK’ in currentOwner..

SQL> CREATE TABLE superavatar
(superavatarID NUMBER CONSTRAINT pk_superavatar PRIMARY KEY, wisdom VARCHAR2(19) NOT NULL CHECK (wisdom IN ('THICK', 'MENTALLY CHALLENGED', 'AWAKE', 'SMART', 'GENIUS')),
currentOwner NUMBER NOT NULL CHECK (currentOwner IN(SELECT userID FROM users)),
fatherOf NUMBER,
motherOf NUMBER);
*
ERROR:
ORA-02251: subquery not allowed here

It doesn’t work.

Please HELP, I have exam tomorrow

thank you
Desy