-- Table CREDITORS
CREATE TABLE CREDITORS (
  CREDITOR_ID                NUMBER NOT NULL,
  CREDITOR                   VARCHAR2(20) NOT NULL
 )
/
-- Indexes for CREDITORS
CREATE  UNIQUE INDEX cd$creditor_id$pk
 ON CREDITORS (CREDITOR_ID)
/
-- Constraints for CREDITORS
ALTER TABLE CREDITORS
 ADD CONSTRAINT cd$creditor_id$pk PRIMARY KEY (CREDITOR_ID)
/

-- Table DEBTORS
CREATE TABLE DEBTORS (
  DEBTOR_ID                  NUMBER NOT NULL,
  FIRST_NAME                 VARCHAR2(15) NOT NULL,
  LAST_NAME                  VARCHAR2(25) NOT NULL
 )
/
-- Indexes for DEBTORS
CREATE  UNIQUE INDEX db$debtor_id$pk
 ON DEBTORS (DEBTOR_ID)
/
-- Constraints for DEBTORS
ALTER TABLE DEBTORS
 ADD CONSTRAINT db$debtor_id$pk PRIMARY KEY (DEBTOR_ID)
/

-- Table DEBTS
CREATE TABLE DEBTS (
  DEBTOR_ID                  NUMBER NOT NULL,
  CREDITOR_ID                NUMBER NOT NULL,
  BALANCE                    NUMBER(8,2) DEFAULT 0.00 NOT NULL,
  REMAINING_CREDIT           NUMBER(8,2) DEFAULT 0.00 NOT NULL
 )
/
-- Constraints for DEBTS
ALTER TABLE DEBTS
 ADD CONSTRAINT ds$creditor_id$fk FOREIGN KEY (CREDITOR_ID)
      REFERENCES CREDITORS(CREDITOR_ID) ON DELETE CASCADE
/
ALTER TABLE DEBTS
 ADD CONSTRAINT ds$debtor_id$fk FOREIGN KEY (DEBTOR_ID)
      REFERENCES DEBTORS(DEBTOR_ID) ON DELETE CASCADE
/