ChristopherYYChan · ChristopherYYChan · Nov 10, 2025 · Nov 11, 2025
diff --git a/02_activities/assignments/DC_Cohort/Assignment1.md b/02_activities/assignments/DC_Cohort/Assignment1.md
@@ -205,5 +205,13 @@ Consider, for example, concepts of fariness, inequality, social structures, marg
 
 
 ```
-Your thoughts...
+The NADRA provides a great example of how value systems are embedded in databases and data systems. At first glance, these systems may appear neutral or purely technical, but their underlying structures reflect deep assumptions about identity, family, and social norms. In NADRA’s case, the database enforces a rigid model of the family unit: every individual must belong to a “complete” biological family, children are registered under married parents, and patriarchal hierarchies are encoded in how family relationships are tracked. This design systematically excludes or marginalizes those whose lives do not fit these norms, such as single mothers, orphans, children born out of wedlock, and the trans-gender community.
+
+Interestingly, while it is an easy fix for programmers technically, it isn’t the same in terms of traditions. This report highlights a broader lesson about the intersection of technology and society: data systems are never neutral. They encode assumptions about social order, gender, family, and legitimacy. They privilege certain forms of identity while rendering others invisible or difficult to verify. Even when social norms evolve, these systems can lag behind, preserving outdated notions and entrenching inequality. Path dependencies in design—such as reliance on paper registries, historical definitions of family, and legacy bureaucratic structures—make these inequities persistent and difficult to rectify.
+
+For everyday data systems, the implications are important. We often interact with identity verification platforms, social services databases, or educational records assuming neutrality. Yet, as NADRA shows, the structure of a database can dictate who is “legitimate” and who is marginalized. Questions of fairness, inclusivity, and justice must therefore extend beyond policy into technical design. System architects and users alike must critically examine who is counted, whose relationships are recognized, and what assumptions are baked into the schema.
+
+It is important to consider how databases can reinforce existing power structures and social hierarchies. Reflecting on its design allows us to ask whether the systems we build—and use—promote inclusivity or exclusion, fairness or bias. While different countries may have different rituals, they should be more inclusive. Recognizing the values embedded in technical infrastructure is the first step toward creating more equitable and socially responsible data systems.
+
+
 ```
diff --git a/02_activities/assignments/DC_Cohort/Assignment1_session1.pdf b/02_activities/assignments/DC_Cohort/Assignment1_session1.pdf
diff --git a/02_activities/assignments/DC_Cohort/assignment1.sql b/02_activities/assignments/DC_Cohort/assignment1.sql
@@ -4,18 +4,20 @@
 
 --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. */
-
-
+SELECT *
+FROM customer_purchases
+WHERE product_id IN (4, 9);
 
 /*2. Write a query that returns all customer purchases and a new calculated column 'price' (quantity * cost_to_customer_per_qty), 
 filtered by customer IDs between 8 and 10 (inclusive) using either:
@@ -26,45 +28,82 @@ filtered by customer IDs between 8 and 10 (inclusive) using either:
 
 
 -- option 2
-
-
+SELECT *,
+       (quantity * cost_to_customer_per_qty) AS price
+FROM customer_purchases
+WHERE customer_id BETWEEN 8 AND 10;
 
 --CASE
 /* 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. */
-
+SELECT 
+    product_id,
+    product_name,
+    CASE 
+        WHEN product_qty_type = 'unit' THEN 'unit'
+        ELSE 'bulk'
+    END AS prod_qty_type_condensed,
+    CASE 
+        WHEN 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 as v
+INNER JOIN vendor_booth_assignments as vba
+    ON v.vendor_id = vba.vendor_id
+ORDER BY v.vendor_name, vba.market_date;
 
 /* SECTION 3 */
 
 -- 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 (market_date) as rental_time
+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. */
-
-
+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 AS c
+INNER JOIN customer_purchases AS cp
+    ON c.customer_id = cp.customer_id
+GROUP BY 
+    c.customer_id, 
+    c.customer_first_name, 
+    c.customer_last_name
+HAVING 
+    SUM(cp.quantity * cp.cost_to_customer_per_qty) > 2000
+ORDER BY 
+    c.customer_last_name,
+    c.customer_first_name;
 
 --Temp Table
 /* 1. Insert the original vendor table into a temp.new_vendor and then add a 10th vendor: 
@@ -77,20 +116,50 @@ 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) 
 */
-
-
+DROP TABLE IF EXISTS temp.new_vendor;
+CREATE TABLE temp.new_vendor AS
+SELECT *
+FROM vendor;
+
+INSERT INTO temp.new_vendor (
+    vendor_id,
+    vendor_name,
+    vendor_type,
+    vendor_owner_first_name,
+    vendor_owner_last_name
+)
+VALUES (
+    10,
+    'Thomass Superfood Store',
+    'Fresh Focused',
+    'Thomas',
+    'Rosenthal'
+);
+SELECT * FROM temp.new_vendor;
 
 -- 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! */
-
+SELECT 
+    customer_id,
+    strftime('%m', market_date) AS month,
+    strftime('%Y', market_date) AS year
+FROM customer_purchases;
 
 
 /* 2. Using the previous query as a base, determine how much money each customer spent in April 2022. 
 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!! */
+SELECT
+    customer_id,
+    SUM(quantity * cost_to_customer_per_qty) AS total_spent
+FROM customer_purchases
+WHERE 
+    strftime('%Y', market_date) = '2022' AND
+    strftime('%m', market_date) = '04'
+GROUP BY customer_id;