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10_stored_routines_as_functions/script.sql

@@ -1 +1,31 @@
--- Write your SQL code here
+-- Write your SQL code here
+--1.Calculate Total Cost for an Order
+DELIMITER //
+
+CREATE FUNCTION calculate_order_total (order_id_in INT) 
+RETURNS DECIMAL(10, 2)
+DETERMINISTIC
+BEGIN
+    DECLARE total_cost DECIMAL(10, 2) DEFAULT 0;
+    SELECT SUM(m.price * oi.quantity) INTO total_cost 
+    FROM Order_Item oi
+    INNER JOIN Menu m ON oi.dish_id = m.dish_id
+    WHERE oi.order_id = order_id_in;
+    RETURN total_cost;
+END //
+
+DELIMITER ;
+
+--2.Calculate Average Menu Item Cost by Category
+DELIMITER //
+
+CREATE FUNCTION calculate_average_menu_cost (category_in VARCHAR(50))
+RETURNS DECIMAL(10, 2)
+DETERMINISTIC
+BEGIN
+    DECLARE avg_cost DECIMAL(10, 2);
+    SELECT AVG(price) INTO avg_cost FROM Menu WHERE category = category_in;
+    RETURN avg_cost;
+END //
+
+DELIMITER ;

11_views/script.sql

@@ -1 +1,26 @@
--- Write your SQL code here
+-- Write your SQL code here
+-- Write your SQL code here
+
+CREATE VIEW ReservationSummary AS
+SELECT 
+    r.reservation_id,
+    c.customer_name, 
+    c.customer_contact, 
+    r.reservation_timeid
+JOIN Tables t ON r.table_id = t.table_id;
+
+
+
+-- View: Customer Order Summary
+CREATE VIEW CustomerOrderSummary AS
+SELECT 
+    c.customer_name, 
+    c.customer_contact,
+    o.order_id, 
+    o.order_timestamp, 
+    o.total_amount,
+    p.payment_date, 
+    p.amount, 
+    p.payment_method  --  Assuming PaymentMethod table linked to Payment 
+FROM Order_Table o
+JOIN Customers c ON o.customer_id = c.customer_id

12_database_transactions/script.sql

@@ -1 +1,12 @@
--- Write your SQL code here
+-- Write your SQL code here
+START TRANSACTION;  
+
+-- Transaction 1: Add a new order   
+INSERT INTO `Order` (Order_ID, Customer_ID, Order_Date, Expected_Delivery_Date, Status, Total_Amount)  
+VALUES (1, 1, NOW(), DATE_ADD(NOW(), INTERVAL 7 DAY), 1, 100);  
+
+--Transaction 2: Add a new payment
+INSERT INTO Payment (Payment_ID, Payment_Date, Order_ID, Amount, Payment_Method, Payment_Status)  
+VALUES (1, NOW(), 1, 100, 'Credit Card', 1);  
+
+COMMIT;

1_database/script.sql

@@ -1 +1,17 @@
--- Write your SQL code here
+-- Write your SQL code here
+-- Database: cjs
+-- DROP DATABASE IF EXISTS cjs;
+CREATE DATABASE cjs WITH
+OWNER = postgres
+TEMPLATE = template0
+ENCODING = 'UTF8'
+CONNECTION LIMIT = 10;
+
+-- SCHEMA: cjs_schema
+-- DROP SCHEMA IF EXISTS cjs_schema;
+CREATE SCHEMA cjs_schema
+    AUTHORIZATION postgres;
+COMMENT ON SCHEMA cjs_schema
+    IS 'CJs schema as used by Advanced Databases group A7 (2024)';
+GRANT USAGE ON SCHEMA cjs_schema TO postgres;
+GRANT ALL ON SCHEMA cjs_schema TO postgres;

2_base_tables/script.sql

@@ -1 +1,101 @@
--- Write your SQL code here
+-- Write your SQL code here
+--Tables without check constraints
+CREATE TABLE Menu (  
+    Menu_ID INT PRIMARY KEY,  
+    Description VARCHAR(100),  
+    Cost INT,  
+    Category VARCHAR(100)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Menu_Ingredient (  
+    Menu_ID INT,  
+    Ingredient VARCHAR(100),  
+    PRIMARY KEY (Menu_ID, Ingredient),  
+    FOREIGN KEY (Menu_ID) REFERENCES Menu(Menu_ID)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Supplier (  
+    Supplier_ID INT PRIMARY KEY,  
+    Item_Description VARCHAR(100)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Supplier_Frequency (  
+    Supplier_ID INT,  
+    Frequency TINYINT,  
+    PRIMARY KEY (Supplier_ID, Frequency),  
+    FOREIGN KEY (Supplier_ID) REFERENCES Supplier(Supplier_ID)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Supplier_Payment (  
+    Supplier_ID INT,  
+    Payment_Method TINYINT,  
+    Payment_Date TIMESTAMP,  
+    Payment_Status TINYINT,  
+    Order_Status TINYINT,  
+    PRIMARY KEY (Supplier_ID, Payment_Date),  
+    FOREIGN KEY (Supplier_ID) REFERENCES Supplier(Supplier_ID)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Reservation (  
+    Reservation_ID INT PRIMARY KEY,  
+    Table_ID INT,  
+    Customer_ID INT,  
+    Customer_Name VARCHAR(100),  
+    Customer_Contact VARCHAR(15),  
+    Capacity INT,  
+    Reservation_Date TIMESTAMP  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Department (  
+    Department_ID INT PRIMARY KEY,  
+    Department_Name VARCHAR(100),  
+    Head_of_Department_ID INT,  
+    Budget_Allocated INT  
+) ENGINE=MyISAM;  
+
+CREATE TABLE `Order` (  
+    Order_ID INT PRIMARY KEY,  
+    Customer_ID INT,  
+    Order_Date TIMESTAMP,  
+    Expected_Delivery_Date TIMESTAMP,  
+    Actual_Delivery_Date TIMESTAMP,  
+    Status TINYINT,  
+    Total_Amount INT  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Payment (  
+    Payment_ID INT PRIMARY KEY,  
+    Payment_Date TIMESTAMP,  
+    Order_ID INT,  
+    Amount INT,  
+    Payment_Method VARCHAR(50),  
+    Payment_Status INT,  
+    FOREIGN KEY (Order_ID) REFERENCES `Order`(Order_ID)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Customer (  
+    Customer_ID INT PRIMARY KEY,  
+    Customer_Name VARCHAR(100),  
+    Customer_Contact VARCHAR(15),  
+    Street_Address VARCHAR(255),  
+    City VARCHAR(255),  
+    Postal_Code VARCHAR(255)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Delivery (  
+    Delivery_ID INT PRIMARY KEY,  
+    Customer_ID INT,  
+    Delivery_Type VARCHAR(30),  
+    Item_ID INT,  
+    Employee_ID INT,  
+    Delivery_Status VARCHAR(20),  
+    Scheduled_Date TIMESTAMP,  
+    FOREIGN KEY (Customer_ID) REFERENCES Customer(Customer_ID)  
+) ENGINE=InnoDB;  
+
+CREATE TABLE Employee (  
+    Employee_ID INT PRIMARY KEY,  
+    Employee_Name VARCHAR(100),  
+    Position_ID INT,  
+    Hire_Date TIMESTAMP  
+) ENGINE=InnoDB;

3_normal_triggers/script.sql

@@ -1 +1,86 @@
--- Write your SQL code here
+-- Write your SQL code here
+-- normal triggers
+
+--trigger 1
+DELIMITER //
+
+CREATE TRIGGER check_stock_before_order
+BEFORE INSERT ON Orders
+FOR EACH ROW
+BEGIN
+    DECLARE insufficient_stock BOOLEAN DEFAULT FALSE;
+    DECLARE ingredient_stock INT;
+
+    DECLARE done INT DEFAULT FALSE;
+    DECLARE cur CURSOR FOR 
+        SELECT i.stock_level 
+        FROM DishIngredients di
+        JOIN Ingredients i ON di.ingredient_id = i.ingredient_id
+        WHERE di.dish_id = NEW.dish_id;
+    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
+
+    OPEN cur;
+
+    read_loop: LOOP
+        FETCH cur INTO ingredient_stock;
+        IF done THEN
+            LEAVE read_loop;
+        END IF;
+
+        -- Check if sufficient stock for each ingredient
+        IF ingredient_stock < (SELECT quantity FROM DishIngredients WHERE dish_id = NEW.dish_id AND ingredient_id = (SELECT ingredient_id FROM DishIngredients WHERE dish_id = NEW.dish_id LIMIT 1)) THEN
+            SET insufficient_stock = TRUE;
+            LEAVE read_loop;
+        END IF;
+    END LOOP;
+
+    CLOSE cur;
+
+    IF insufficient_stock THEN
+        SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Insufficient stock for this order.';
+    END IF;
+END; //
+
+DELIMITER ;
+
+--trigger 2
+DELIMITER //
+
+CREATE TRIGGER check_stock_before_order_update
+BEFORE UPDATE ON Orders
+FOR EACH ROW
+BEGIN
+    DECLARE insufficient_stock BOOLEAN DEFAULT FALSE;
+    DECLARE ingredient_stock INT;
+
+    DECLARE done INT DEFAULT FALSE;
+    DECLARE cur CURSOR FOR 
+        SELECT i.stock_level 
+        FROM DishIngredients di
+        JOIN Ingredients i ON di.ingredient_id = i.ingredient_id
+        WHERE di.dish_id = NEW.dish_id;
+    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
+
+    OPEN cur;
+
+    read_loop: LOOP
+        FETCH cur INTO ingredient_stock;
+        IF done THEN
+            LEAVE read_loop;
+        END IF;
+
+        -- Check if sufficient stock for each ingredient
+        IF ingredient_stock < (SELECT quantity FROM DishIngredients WHERE dish_id = NEW.dish_id AND ingredient_id = (SELECT ingredient_id FROM DishIngredients WHERE dish_id = NEW.dish_id LIMIT 1)) THEN
+            SET insufficient_stock = TRUE;
+            LEAVE read_loop;
+        END IF;
+    END LOOP;
+
+    CLOSE cur;
+
+    IF insufficient_stock THEN
+        SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Insufficient stock for this order.';
+    END IF;
+END; //
+
+DELIMITER ;