create table Problems (
id integer primary key,
added datetime,
+ fen varchar,
uid integer,
vid integer,
instruction text,
foreign key (vid) references Variants(id)
);
+create table News (
+ id integer primary key,
+ uid integer,
+ added datetime,
+ content text,
+ foreign key (uid) references Users(id)
+);
+
create table Challenges (
id integer primary key,
added datetime,