AmmarMahzan · AmmarMahzan · Apr 24, 2025 · Apr 28, 2025 · Apr 30, 2025 · Apr 30, 2025
diff --git a/02_activities/assignments/AmmarMahzan_SQL_Assignment#2-Section1.pdf b/02_activities/assignments/AmmarMahzan_SQL_Assignment#2-Section1.pdf
diff --git a/02_activities/assignments/Assignment2.md b/02_activities/assignments/Assignment2.md
@@ -45,16 +45,63 @@ There are several tools online you can use, I'd recommend [Draw.io](https://www.
 
 **HINT:** You do not need to create any data for this prompt. This is a conceptual model only. 
 
+ANSWER:
+For this prompt, I designed an Entity-Relationship Diagram (ERD) that includes the following entities:
+	•	Employee
+	•	Customer
+	•	Orders
+	•	Sales
+	•	Books
+	•	OrderDetails
+	•	Date
+
+Each table includes essential attributes and primary/foreign keys to establish relationships:
+	•	Books to Orders: Many-to-Many
+	•	Customer to Orders: One-to-Many
+	•	Employees to Orders: One-to-Many
+	•	Sales to Orders: One-to-Many
+	•	Date to Orders: One-to-Many
+
+📎 See ERD: Prompt#1.png
+
+
 #### Prompt 2
 We want to create employee shifts, splitting up the day into morning and evening. Add this to the ERD.
 
+ANSWER:
+To model employee shifts, I added a new table called Shifts, which includes:
+	•	ShiftID (Primary Key)
+	•	EmployeeID (Foreign Key)
+	•	DateID (Foreign Key)
+	•	ShiftType (Morning or Evening)
+	•	StartTime, EndTime
+
+This links to both the Employee and Date tables, showing when and which shift was assigned.
+
+📎 See updated ERD with Shifts: Prompt#2.png
+
+
 #### Prompt 3
 The store wants to keep customer addresses. Propose two architectures for the CUSTOMER_ADDRESS table, one that will retain changes, and another that will overwrite. Which is type 1, which is type 2? 
 
 **HINT:** search type 1 vs type 2 slowly changing dimensions. 
 
 ```
-Your answer...
+Type 1 – Overwrites Old Address
+	•	This model keeps only the most recent address by updating the same row.
+	•	Pros: Simple, minimal storage
+	•	Cons: Historical address info is lost
+
+📎 See ERD: Prompt#3.Type1.png
+
+Type 2 – Retains Address History
+	•	This model retains old addresses and uses an EffectiveDate (and optionally EndDate or IsActive) to track changes over time.
+	•	Pros: Keeps history, useful for analytics
+	•	Cons: Slightly more complex to manage
+
+📎 See ERD: Prompt3-Type2.png
+
+
 ```
 
 ***

diff --git a/02_activities/assignments/DSI_SQL_A1.png b/02_activities/assignments/DSI_SQL_A1.png
diff --git a/02_activities/assignments/Prompt#1.png b/02_activities/assignments/Prompt#1.png
diff --git a/02_activities/assignments/Prompt#2.png b/02_activities/assignments/Prompt#2.png
diff --git a/02_activities/assignments/Prompt#3.Type1.png b/02_activities/assignments/Prompt#3.Type1.png
diff --git a/02_activities/assignments/Prompt3-Type2.png b/02_activities/assignments/Prompt3-Type2.png
diff --git a/02_activities/assignments/assignment1.sql b/02_activities/assignments/assignment1.sql
@@ -4,53 +4,87 @@
 
 --SELECT
 /* 1. Write a query that returns everything in the customer table. */
+SELECT * FROM customer;
 
 
 
 /* 2. Write a query that displays all of the columns and 10 rows from the cus- tomer table, 
 sorted by customer_last_name, then customer_first_ name. */
-
+SELECT * 
+FROM customer
+ORDER BY customer_last_name, customer_first_name
+LIMIT 10;
 
 
 --WHERE
 /* 1. Write a query that returns all customer purchases of product IDs 4 and 9. */
--- option 1
-
-
--- option 2
+-- option 1: Using IN
+SELECT * 
+FROM customer_purchases
+WHERE product_id IN (4, 9);
 
+-- option 2: Using OR
+SELECT * 
+FROM customer_purchases
+WHERE product_id = 4 OR product_id = 9;
 
 
 /*2. Write a query that returns all customer purchases and a new calculated column 'price' (quantity * cost_to_customer_per_qty), 
 filtered by vendor IDs between 8 and 10 (inclusive) using either:
 	1.  two conditions using AND
 	2.  one condition using BETWEEN
 */
--- option 1
+-- option :  using AND
+SELECT *, 
+       quantity * cost_to_customer_per_qty AS price
+FROM customer_purchases
+WHERE vendor_id >= 8 AND vendor_id <= 10;
 
 
--- option 2
+-- option 2: using BETWEEN
+SELECT *, 
+       quantity * cost_to_customer_per_qty AS price
+FROM customer_purchases
+WHERE vendor_id BETWEEN 8 AND 10;
 
 
-
---CASE
+--CASE: Condense quantity type
 /* 1. Products can be sold by the individual unit or by bulk measures like lbs. or oz. 
 Using the product table, write a query that outputs the product_id and product_name
 columns and add a column called prod_qty_type_condensed that displays the word “unit” 
 if the product_qty_type is “unit,” and otherwise displays the word “bulk.” */
+SELECT product_id, product_name,
+  CASE 
+    WHEN product_qty_type = 'unit' THEN 'unit'
+    ELSE 'bulk'
+  END AS prod_qty_type_condensed
+FROM product;
 
 
 
 /* 2. We want to flag all of the different types of pepper products that are sold at the market. 
 add a column to the previous query called pepper_flag that outputs a 1 if the product_name 
-contains the word “pepper” (regardless of capitalization), and otherwise outputs 0. */
-
+contains the word “pepper” (regardless of capitalization), and otherwise outputs 0. :Add pepper flag */
+SELECT product_id, product_name,
+  CASE 
+    WHEN product_qty_type = 'unit' THEN 'unit'
+    ELSE 'bulk'
+  END AS prod_qty_type_condensed,
+  CASE 
+    WHEN LOWER(product_name) LIKE '%pepper%' THEN 1
+    ELSE 0
+  END AS pepper_flag
+FROM product;
 
 
 --JOIN
 /* 1. Write a query that INNER JOINs the vendor table to the vendor_booth_assignments table on the 
 vendor_id field they both have in common, and sorts the result by vendor_name, then market_date. */
-
+SELECT * 
+FROM vendor v
+INNER JOIN vendor_booth_assignments vba 
+  ON v.vendor_id = vba.vendor_id
+ORDER BY v.vendor_name, vba.market_date;
 
 
 
@@ -59,15 +93,26 @@ vendor_id field they both have in common, and sorts the result by vendor_name, t
 -- AGGREGATE
 /* 1. Write a query that determines how many times each vendor has rented a booth 
 at the farmer’s market by counting the vendor booth assignments per vendor_id. */
-
+SELECT vendor_id, COUNT(*) AS booth_rentals
+FROM vendor_booth_assignments
+GROUP BY vendor_id;
 
 
 /* 2. The Farmer’s Market Customer Appreciation Committee wants to give a bumper 
 sticker to everyone who has ever spent more than $2000 at the market. Write a query that generates a list 
 of customers for them to give stickers to, sorted by last name, then first name. 
 
-HINT: This query requires you to join two tables, use an aggregate function, and use the HAVING keyword. */
-
+HINT: This query requires you to join two tables, use an aggregate function, and use the HAVING keyword. : Customers who spent more than $2000
+SELECT c.customer_id,*/
+SELECT c.customer_id,
+       c.customer_first_name,
+       c.customer_last_name,
+       SUM(cp.quantity * cp.cost_to_customer_per_qty) AS total_spent
+FROM customer c
+JOIN customer_purchases cp ON c.customer_id = cp.customer_id
+GROUP BY c.customer_id
+HAVING total_spent > 2000
+ORDER BY c.customer_last_name, c.customer_first_name;
 
 
 --Temp Table
@@ -81,14 +126,25 @@ When inserting the new vendor, you need to appropriately align the columns to be
 -> To insert the new row use VALUES, specifying the value you want for each column:
 VALUES(col1,col2,col3,col4,col5) 
 */
+-- 1. Create temp table from vendor
+CREATE TEMP TABLE new_vendor AS
+SELECT * FROM vendor;
 
+-- 2. Add 10th vendor
+INSERT INTO new_vendor
+VALUES (10, 'Thomass Superfood Store', 'Fresh Focused', 'Thomas Rosenthal', NULL);
 
 
 -- Date
 /*1. Get the customer_id, month, and year (in separate columns) of every purchase in the customer_purchases table.
 
 HINT: you might need to search for strfrtime modifers sqlite on the web to know what the modifers for month 
 and year are! */
+-- 1. Get customer_id, month, and year of each purchase
+SELECT customer_id,
+       STRFTIME('%m', market_date) AS month,
+       STRFTIME('%Y', market_date) AS year
+FROM customer_purchases;
 
 
 
@@ -97,4 +153,10 @@ Remember that money spent is quantity*cost_to_customer_per_qty.
 
 HINTS: you will need to AGGREGATE, GROUP BY, and filter...
 but remember, STRFTIME returns a STRING for your WHERE statement!! */
-
+-- 2. Total money spent in April 2022
+SELECT customer_id,
+       SUM(quantity * cost_to_customer_per_qty) AS april_2022_spent
+FROM customer_purchases
+WHERE STRFTIME('%m', market_date) = '04'
+  AND STRFTIME('%Y', market_date) = '2022'
+GROUP BY customer_id;