Simple SQL-request

SQLrequest.sql

CREATE TABLE customers (
id INTEGER PRIMARY KEY,
CustomerId INTEGER, 
RegistrationDateTime DATE, 
Name TEXT);

INSERT INTO customers (CustomerId, RegistrationDateTime, Name)
VALUES (1, "2017-11-25", "Bulat");
INSERT INTO customers (CustomerId, RegistrationDateTime, Name)
VALUES (2, "2017-12-15", "Alina");
INSERT INTO customers (CustomerId, RegistrationDateTime, Name)
VALUES (3, "2018-01-13", "Sever");
INSERT INTO customers (CustomerId, RegistrationDateTime, Name)
VALUES (4, "2018-01-14", "Vasya");

CREATE TABLE purchase (
id INTEGER PRIMARY KEY,
CustomerId INTEGER, 
PurchaiseDatetime DATE, 
ProductName TEXT);

INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (1, "2017-11-25", "Milk");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (2, "2017-12-15", "Milk");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (1, "2017-12-15", "Sour cream");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (2, "2018-01-01", "Milk");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (3, "2018-01-13", "Milk");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (1, "2018-01-14", "Milk");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (4, "2018-01-14", "Sour cream");
INSERT INTO purchase (CustomerId, PurchaiseDatetime, ProductName)
VALUES (4, "2018-01-15", "Milk");

SELECT purchase.PurchaiseDatetime, purchase.CustomerId, customers.Name, purchase.ProductName
FROM purchase
INNER JOIN customers ON purchase.CustomerId = customers.CustomerId
WHERE ProductName = "Milk" AND ProductName != "Sour cream" AND PurchaiseDatetime < '2018-01-16' AND PurchaiseDatetime > '2017-12-16'
GROUP BY PurchaiseDatetime;