Group of options.

Column	Type	Constraint	Description
shop	TEXT	PRIMARY KEY	Shop ID. (shop.username)
id	INTEGER		Identifier.
selection	INTEGER	NOT NULL	Selection method of group. 0: Single selection 1: Multiple selection
atleast	INTEGER	NOT NULL	Least number of option that a customer must choose to buy a product which is associated with this group. If Single selection is specified, this column must be 0 or 1.

CREATE TABLE option_group(
shop      TEXT,
id        INTEGER,
selection INTEGER NOT NULL,
atleast   INTEGER NOT NULL,
PRIMARY KEY(shop, id)
);

Multilingualized name of option_group.

Column	Type	Constraint	Description
shop	TEXT	PRIMARY KEY	Shop ID. (shop.username)
group_id	INTEGER		Group ID. (option_group.id)
lang	TEXT		Language key.
name	TEXT	NOT NULL	Group name.

CREATE TABLE option_group_content(
shop      TEXT,
lang      TEXT,
group_id  INTEGER,
name      TEXT    NOT NULL,
PRIMARY KEY(shop, lang, group_id)
);