CREATE TABLE Procuctcat (
    id   TEXT PRIMARY KEY
              UNIQUE
              NOT NULL,
    name TEXT NOT NULL
);

CREATE TABLE Product (
    id      TEXT    UNIQUE
                    NOT NULL
                    PRIMARY KEY,
    itemid  TEXT    UNIQUE
                    NOT NULL,
    cat     TEXT    NOT NULL
                    REFERENCES Procuctcat (id) ON UPDATE CASCADE,
    name    TEXT    NOT NULL,
    price   INTEGER NOT NULL,
    count   INTEGER NOT NULL,
    archive INTEGER NOT NULL
);

CREATE TABLE Sales (
    id       TEXT    UNIQUE
                     NOT NULL
                     PRIMARY KEY,
    itemid   TEXT    NOT NULL
                     REFERENCES Product (itemid) ON UPDATE CASCADE,
    cat      TEXT    NOT NULL
                     REFERENCES Procuctcat (id) ON UPDATE CASCADE,
    name     TEXT    NOT NULL
                     REFERENCES Product (name) ON UPDATE CASCADE,
    price    INTEGER NOT NULL,
    count    INTEGER NOT NULL,
    discount INTEGER NOT NULL,
    date     NUMERIC NOT NULL
);

SELECT Sales.count, Sales.discount, Product.name
	FROM Sales
	INNER JOIN Product
	ON Sales.product_id = Product.id
	WHERE id = '$id';"

SELECT Sales.count, Sales.discount, Product.name
	FROM Sales
	INNER JOIN Product
	ON Sales.product_id = Product.id
	WHERE Sales.id = '$id';"