Query

DROP TABLE IF EXISTS users;
DROP TABLE IF EXISTS timetable;


CREATE TABLE users (
    sapid VARCHAR2(50) PRIMARY KEY,
    name VARCHAR2(100) NOT NULL,
    password VARCHAR2(100) NOT NULL
);

CREATE TABLE timetable (
    subjects VARCHAR2(50) NULL,
    monday NUMBER, 
    tuesday NUMBER, 
    wednesday NUMBER, 
    thursday NUMBER, 
    friday NUMBER, 
    saturday NUMBER, 
    total NUMBER NOT NULL
);
ALTER TABLE timetable ADD yourtotal NUMBER DEFAULT 0;

CREATE TABLE last_entry ( 
    subject VARCHAR2(50) PRIMARY KEY, 
    day VARCHAR2(20),
   	entry_time TIMESTAMP
);

INSERT INTO timetable (sapid, total) 
VALUES ('S12345', 40);