Ivan Galkin

shop_db.sql

@@ -0,0 +1,129 @@
+CREATE TYPE SEX AS ENUM ('m', 'f');
+
+CREATE TABLE manufacturers (
+    manufacturer_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    manufacturer_name TEXT NOT NULL UNIQUE,
+    contact_info TEXT,
+    address TEXT
+);
+
+CREATE TABLE products (
+    product_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    manufacturer_id INTEGER NOT NULL,
+    product_category TEXT NOT NULL,
+    product_name TEXT NOT NULL,
+    selling_price NUMERIC(10,2) NOT NULL CHECK (selling_price > 0),
+    purchase_cost NUMERIC(10,2) NOT NULL CHECK (purchase_cost >= 0),
+    stock_quantity INTEGER NOT NULL CHECK (stock_quantity >= 0),
+    description TEXT,
+    FOREIGN KEY (manufacturer_id) REFERENCES manufacturers(manufacturer_id)
+);
+
+CREATE TABLE product_descriptions (
+    description_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    product_id INTEGER NOT NULL UNIQUE,
+    description TEXT,
+    FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE
+);
+
+CREATE TABLE table_phone (
+    id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    phone TEXT NOT NULL CHECK ( phone <> '' )
+);
+
+CREATE TABLE table_email (
+    id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    email TEXT NOT NULL CHECK ( email <> '' )
+);
+
+CREATE TABLE persons (
+    person_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    first_name TEXT NOT NULL,
+    second_name TEXT NOT NULL,
+    middle_name TEXT NOT NULL,
+    phone_id INTEGER NOT NULL,
+    email_id INTEGER NOT NULL,
+    sex SEX NOT NULL,
+    FOREIGN KEY (email_id) REFERENCES table_email(id),
+    FOREIGN KEY (phone_id) REFERENCES table_phone(id)
+);
+
+CREATE TABLE employees (
+    employee_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    person_id INTEGER NOT NULL,
+    position TEXT NOT NULL,
+    salary NUMERIC(10,2) NOT NULL,
+    employment_date DATE NOT NULL,
+    FOREIGN KEY (person_id) REFERENCES persons(person_id)
+);
+
+CREATE TABLE customers (
+    customer_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    person_id INTEGER NOT NULL,
+    discount_rate NUMERIC(3,2) NOT NULL DEFAULT 0.00,
+    subscription BOOLEAN NOT NULL DEFAULT FALSE,
+    registration_date DATE DEFAULT CURRENT_DATE,
+    FOREIGN KEY (person_id) REFERENCES persons(person_id)
+);
+
+CREATE TABLE sales_transactions (
+    transaction_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    transaction_date DATE NOT NULL DEFAULT CURRENT_DATE,
+    customer_id INTEGER NOT NULL,
+    employee_id INTEGER NOT NULL,
+    total_before_discount NUMERIC(10,2) NOT NULL,
+    transaction_total NUMERIC(10,2) NOT NULL,
+    FOREIGN KEY (customer_id) REFERENCES customers(customer_id),
+    FOREIGN KEY (employee_id) REFERENCES employees(employee_id)
+);
+
+CREATE TABLE transaction_items (
+    item_id INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    transaction_id INTEGER NOT NULL,
+    product_id INTEGER NOT NULL,
+    quantity INTEGER NOT NULL CHECK (quantity > 0),
+    unit_price NUMERIC(10,2) NOT NULL,
+    applied_discount_rate NUMERIC(5,2) DEFAULT 0,
+    item_total NUMERIC(10,2) NOT NULL,
+    FOREIGN KEY (transaction_id) REFERENCES sales_transactions(transaction_id) ON DELETE CASCADE,
+    FOREIGN KEY (product_id) REFERENCES products(product_id)
+);
+
+CREATE OR REPLACE FUNCTION update_product_stock()
+RETURNS TRIGGER AS $$
+BEGIN
+
+    IF (SELECT stock_quantity FROM products WHERE product_id = NEW.product_id) < NEW.quantity THEN
+        RAISE EXCEPTION 'Недостаточно товара на складе. ', NEW.product_id;
+    END IF;
+
+    UPDATE products
+    SET stock_quantity = stock_quantity - NEW.quantity
+    WHERE product_id = NEW.product_id;
+
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS trg_update_stock_on_sale ON transaction_items;
+CREATE TRIGGER trg_update_stock_on_sale
+BEFORE INSERT ON transaction_items
+FOR EACH ROW
+EXECUTE FUNCTION update_product_stock();
+
+INSERT INTO manufacturers (manufacturer_name) VALUES
+('Производитель 1'),
+('Производитель 2'),
+('Производитель 3')
+
+
+INSERT INTO products (manufacturer_id, product_category, product_name, selling_price, purchase_cost, stock_quantity)
+VALUES
+(1, 'Электроника', 'Телефон', 50000.00, 40000.00, 100),
+(2, 'Одежда', 'Футболка', 1500.00, 800.00, 200)
+
+
+INSERT INTO product_descriptions (product_id, description)
+VALUES
+(1, 'Смартфон'),
+(2, 'футболка')