CREATE TABLE users
(
    userid     INTEGER default 0 not null
        primary key,
    age        TEXT    not null,
    u_gender   TEXT    not null,
    occupation TEXT   not null
);
users
CREATE TABLE "directors"
(
    directorid  INTEGER not null
        primary key,
    d_quality   INTEGER not null,
    avg_revenue INTEGER not null
);
directors
CREATE TABLE "actors"
(
    actorid   INTEGER not null
        primary key,
    a_gender  TEXT    not null,
    a_quality INTEGER not null
);
actors
CREATE TABLE "movies"
(
    movieid     INTEGER default 0 not null
        primary key,
    year        INTEGER           not null,
    isEnglish   TEXT              not null,
    country     TEXT              not null,
    runningtime INTEGER           not null
);
movies
CREATE TABLE "movies2actors"
(
    movieid  INTEGER not null
        references movies
            on update cascade on delete cascade,
    actorid  INTEGER not null
        references actors
            on update cascade on delete cascade,
    cast_num INTEGER not null,
    primary key (movieid, actorid)
);
movies2actors
CREATE TABLE "movies2directors"
(
    movieid    INTEGER not null
        references movies
            on update cascade on delete cascade,
    directorid INTEGER not null
        references directors
            on update cascade on delete cascade,
    genre      TEXT    not null,
    primary key (movieid, directorid)
);
movies2directors
CREATE TABLE "u2base"
(
    userid  INTEGER default 0 not null
        references users
            on update cascade on delete cascade,
    movieid INTEGER           not null
        references movies
            on update cascade on delete cascade,
    rating  TEXT              not null,
    primary key (userid, movieid)
);
u2base
original_column_name,column_name,column_description,data_format,value_description
directorid,director id,unique identification number of actors directors,integer,
d_quality ,director quality,director quality ,integer,"higher value is better, lower is the worse"
avg_revenue,average revenue,average revenue,integer,"higher value is the higher, lower is the lower"
directors
original_column_name,column_name,column_description,data_format,value_description
actorid,actor id,unique identificator number of actors,integer,
a_gender,actor gender,actor gender,text,"M: male;
F: female"
a_quality,actor quality,actor quality,integer,"higher is better, lower is the worse"
actors
original_column_name,column_name,column_description,data_format,value_description
userid,user id,unique identifier number of users,integer,
age,age,age,text,"1: 1-18 years old; 
18: 18-25 years old; 
25: 25-35 years old; 
35: 35-45 years old; 
45: 45-50 years old; 
50: 50-56 years old; 
56: over 56 years old"
u_gender,user gender,user gender,text,M / F: Male / Female
occupation ,,occupation,text,
users
original_column_name,column_name,column_description,data_format,value_description
movieid,movie id,identifier number of movies,integer,
directorid,director id,identifier number of directors,integer,
genre,genre,genre of movies,text,
movies2directors
original_column_name,column_name,column_description,data_format,value_description
userid,user id,identifier number of users,integer,
movieid,movie id,identifier number of movie,integer,
rating,rating,ratings of movies,text,"higher value refers to higher satisfactory, each value is the rating of movies left by users."
u2base
original_column_name,column_name,column_description,data_format,value_description
movieid,movie id,unique identifier number of movies,integer,
year,year,year,integer,"4: newest;

1: oldest

higher value means newer published date"
isEnglish,is English,is English,text,
country,,country,text,
runningtime,,,integer,
movies
original_column_name,column_name,column_description,data_format,value_description
movieid,movie id,identifier number of movies,integer,
,,,,
actorid,actor id,identifier number of actors,integer,
,,,,
cast_num,cast number,cast number,integer,
movies2actors