text: DROP TABLE customer_360.account;
  DROP TABLE customer_360.customer;
  DROP TABLE customer_360.merchant;
  DROP TABLE customer_360.owned_by;
  DROP TABLE customer_360.parent_of;
  DROP TABLE customer_360.purchased;
  DROP TABLE customer_360.transfer;
  
  CREATE TABLE customer_360.account (
    id NUMBER NOT NULL
  , type VARCHAR2(20) 
  , account_no VARCHAR2(20)
  , balance NUMBER
  , CONSTRAINT account_pk PRIMARY KEY (id)
  );
  
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (201,'account','xxx-yyy-201',1500);
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (202,'account','xxx-yyy-202',200);
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (203,'account','xxx-yyy-203',2100);
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (204,'account','xxx-yyy-204',100);
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (211,'account','xxx-zzz-204',NULL);
  INSERT INTO customer_360.account (id,type,account_no,balance) VALUES (212,'account','xxx-zzz-204',NULL);
  COMMIT;
  
  CREATE TABLE customer_360.customer (
    id NUMBER NOT NULL, 
    type VARCHAR2(20), 
    name VARCHAR2(20), 
    age NUMBER, 
    location VARCHAR2(20), 
    gender VARCHAR2(20), 
    student VARCHAR2(20)
  , CONSTRAINT customer_pk PRIMARY KEY (id)
  );
  
  INSERT INTO customer_360.customer (id,type,name,age,location,gender,student) VALUES (101,'customer','John',10,'Boston',NULL,NULL);
  INSERT INTO customer_360.customer (id,type,name,age,location,gender,student) VALUES (102,'customer','Mary',NULL,NULL,'F',NULL);
  INSERT INTO customer_360.customer (id,type,name,age,location,gender,student) VALUES (103,'customer','Jill',NULL,'Boston',NULL,NULL);
  INSERT INTO customer_360.customer (id,type,name,age,location,gender,student) VALUES (104,'customer','Todd',NULL,NULL,NULL,'true');
  COMMIT;
  
  CREATE TABLE customer_360.merchant (
    id NUMBER NOT NULL 
  , type VARCHAR2(20) 
  , name VARCHAR2(20)
  , CONSTRAINT merchant_pk PRIMARY KEY (id)
  );
  
  INSERT INTO customer_360.merchant (id,type,name) VALUES (301,'merchant','Apple Store');
  INSERT INTO customer_360.merchant (id,type,name) VALUES (302,'merchant','PC Paradise');
  INSERT INTO customer_360.merchant (id,type,name) VALUES (303,'merchant','Kindle Store');
  INSERT INTO customer_360.merchant (id,type,name) VALUES (304,'merchant','Asia Books');
  INSERT INTO customer_360.merchant (id,type,name) VALUES (305,'merchant','ABC Travel');
  COMMIT;
  
  CREATE TABLE customer_360.owned_by (
    from_id NUMBER, 
    to_id NUMBER, 
    since VARCHAR2(20)
  );
  
  INSERT INTO customer_360.owned_by (from_id,to_id,since) VALUES (201,101,'2015-10-04');
  INSERT INTO customer_360.owned_by (from_id,to_id,since) VALUES (202,102,'2012-09-13');
  INSERT INTO customer_360.owned_by (from_id,to_id,since) VALUES (203,103,'2016-02-04');
  INSERT INTO customer_360.owned_by (from_id,to_id,since) VALUES (204,104,'2018-01-05');
  COMMIT;
  
  CREATE TABLE customer_360.parent_of (
    from_id NUMBER
  , to_id NUMBER
  );
  
  INSERT INTO customer_360.parent_of (from_id,to_id) VALUES (103,104);
  
  CREATE TABLE customer_360.purchased (
    from_id NUMBER, 
    to_id NUMBER, 
    amount NUMBER
  );
  
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (201,301,800);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (201,302,15);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (202,301,150);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (202,302,20);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (202,304,10);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (203,301,350);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (203,302,20);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (203,303,15);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (204,303,10);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (204,304,15);
  INSERT INTO customer_360.purchased (from_id,to_id,amount) VALUES (204,305,450);
  COMMIT;
  
  CREATE TABLE customer_360.transfer (
    from_id NUMBER
  , to_id NUMBER
  , amount NUMBER
  , "DATE" VARCHAR2(20)
  );
  
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (201,202,200,'2018-10-05');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (211,202,900,'2018-10-06');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (202,212,850,'2018-10-06');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (201,203,500,'2018-10-07');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (203,204,450,'2018-10-08');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (204,201,400,'2018-10-09');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (202,203,100,'2018-10-10');
  INSERT INTO customer_360.transfer (from_id,to_id,amount,"DATE") VALUES (202,201,300,'2018-10-10');
  COMMIT;
  