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Assignment two #2

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08b254d
Commit for SQL assignment 1
JesusSolisR Aug 11, 2025
5885ffc
Adding required files for SQL Assignment 2:
JesusSolisR Aug 18, 2025
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Binary file added 02_activities/assignments/Assignment 2 - Bookstore Logical Model - Jesus Solis.pdf
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Binary file added 02_activities/assignments/FarmersMarket DB - Logical Data Model of two tables .pdf
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65 changes: 57 additions & 8 deletions 02_activities/assignments/assignment1.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -6,20 +6,25 @@
/* 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

SELECT * FROM customer_purchases c WHERE c.product_id IN (4,9);

-- option 2


SELECT * FROM customer_purchases c WHERE c.product_id = 4 OR c.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:
Expand All @@ -28,30 +33,48 @@ filtered by vendor IDs between 8 and 10 (inclusive) using either:
*/
-- option 1

SELECT *, (quantity * cost_to_customer_per_qty) AS 'price' FROM customer_purchases WHERE vendor_id >= 8 AND vendor_id <= 10;

-- option 2


SELECT *, (quantity * cost_to_customer_per_qty) AS 'price' FROM customer_purchases WHERE vendor_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 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 v.vendor_id, v.vendor_name, v.vendor_type, v.vendor_owner_first_name, v.vendor_owner_last_name, vb.booth_number, vb.market_date
FROM vendor v
INNER JOIN vendor_booth_assignments vb
ON v.vendor_id = vb.vendor_id
ORDER BY v.vendor_name, vb.market_date;


/* SECTION 3 */
Expand All @@ -60,14 +83,21 @@ vendor_id field they both have in common, and sorts the result by vendor_name, t
/* 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 count 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 spent
FROM customer AS c
JOIN customer_purchases AS cp ON cp.customer_id = c.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
Expand All @@ -82,19 +112,38 @@ When inserting the new vendor, you need to appropriately align the columns to be
VALUES(col1,col2,col3,col4,col5)
*/


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'
);

-- 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('%m', market_date) = '04'
AND strftime('%Y', market_date) = '2022'
GROUP BY customer_id;
134 changes: 127 additions & 7 deletions 02_activities/assignments/assignment2.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,11 @@ The `||` values concatenate the columns into strings.
Edit the appropriate columns -- you're making two edits -- and the NULL rows will be fixed.
All the other rows will remain the same.) */

SELECT
product_name || ', ' ||
COALESCE(product_size, '') || ' (' ||
COALESCE(product_qty_type, 'unit') || ')'
FROM product;


--Windowed Functions
Expand All @@ -32,18 +37,48 @@ each new market date for each customer, or select only the unique market dates p
(without purchase details) and number those visits.
HINT: One of these approaches uses ROW_NUMBER() and one uses DENSE_RANK(). */

/*Approach using ROW_NUMBER() */
SELECT
customer_id,
market_date,
ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY market_date) AS visit_number
FROM customer_purchases;

/*Approach using DENSE_RANK() selecting distinct market dates */
SELECT
customer_id,
market_date,
DENSE_RANK() OVER (PARTITION BY customer_id ORDER BY market_date) AS visit_number
FROM ( SELECT DISTINCT customer_id, market_date FROM customer_purchases ) visits;

/* 2. Reverse the numbering of the query from a part so each customer’s most recent visit is labeled 1,
then write another query that uses this one as a subquery (or temp table) and filters the results to
only the customer’s most recent visit. */

/*Reversing the result to customer's most recent visit */
SELECT
customer_id,
market_date,
ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY market_date DESC) AS visit_number
FROM customer_purchases;


/*Using Temporary table */

DROP TABLE IF EXISTS temp.customer_visits;
CREATE TEMP TABLE IF NOT EXISTS temp.customer_visits AS
SELECT *, ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY market_date DESC) AS visit_number
FROM customer_purchases;

SELECT * FROM temp.customer_visits WHERE visit_number = 1;


/* 3. Using a COUNT() window function, include a value along with each row of the
customer_purchases table that indicates how many different times that customer has purchased that product_id. */


SELECT *, COUNT(*) OVER (PARTITION BY customer_id, product_id) AS count_cstmr_prod_purchase FROM customer_purchases;


-- String manipulations
/* 1. Some product names in the product table have descriptions like "Jar" or "Organic".
Expand All @@ -57,10 +92,23 @@ Remove any trailing or leading whitespaces. Don't just use a case statement for

Hint: you might need to use INSTR(product_name,'-') to find the hyphens. INSTR will help split the column. */


SELECT p.*, p.product_name,
TRIM(CASE
WHEN INSTR(p.product_name, '-') > 0
THEN SUBSTR(p.product_name, INSTR(p.product_name, '-') + 1)
ELSE NULL
END) AS description
FROM product p;

/* 2. Filter the query to show any product_size value that contain a number with REGEXP. */

SELECT p.*, p.product_name,
TRIM(CASE
WHEN INSTR(p.product_name, '-') > 0
THEN SUBSTR(p.product_name, INSTR(p.product_name, '-') + 1)
ELSE NULL
END) AS description
FROM product p
WHERE p.product_size REGEXP '[0-9]';


-- UNION
Expand All @@ -74,8 +122,35 @@ HINT: There are a possibly a few ways to do this query, but if you're struggling
with a UNION binding them. */


DROP TABLE IF EXISTS temp.date_sales;
DROP TABLE IF EXISTS temp.date_sales_ranked;

CREATE TEMP TABLE IF NOT EXISTS temp.date_sales AS
SELECT
market_date,
SUM(quantity * cost_to_customer_per_qty) AS total_sales
FROM customer_purchases
GROUP BY market_date;

CREATE TEMP TABLE IF NOT EXISTS temp.date_sales_ranked AS
SELECT
market_date,
total_sales,
DENSE_RANK() OVER (ORDER BY total_sales DESC) AS best_day_rank,
DENSE_RANK() OVER (ORDER BY total_sales ASC) AS worst_day_rank
FROM date_sales;


SELECT market_date, total_sales, 'Best Day' AS day
FROM temp.date_sales_ranked
WHERE best_day_rank = 1

UNION

SELECT market_date, total_sales, 'Worst Day' AS day
FROM temp.date_sales_ranked
WHERE worst_day_rank = 1;

/* SECTION 3 */

-- Cross Join
Expand All @@ -88,7 +163,15 @@ Remember, CROSS JOIN will explode your table rows, so CROSS JOIN should likely b
Think a bit about the row counts: how many distinct vendors, product names are there (x)?
How many customers are there (y).
Before your final group by you should have the product of those two queries (x*y). */

SELECT
v.vendor_name,
p.product_name,
(customer_count * vi.original_price * 5) AS potential_sales_per_product
FROM vendor_inventory vi
JOIN vendor v ON vi.vendor_id = v.vendor_id
JOIN product p ON vi.product_id = p.product_id
CROSS JOIN (SELECT COUNT(*) AS customer_count FROM customer)
GROUP BY v.vendor_name, p.product_name, vi.original_price;


-- INSERT
Expand All @@ -97,18 +180,22 @@ This table will contain only products where the `product_qty_type = 'unit'`.
It should use all of the columns from the product table, as well as a new column for the `CURRENT_TIMESTAMP`.
Name the timestamp column `snapshot_timestamp`. */


CREATE TABLE product_units AS
SELECT *,CURRENT_TIMESTAMP AS snapshot_timestamp
FROM product
WHERE product_qty_type = 'unit';

/*2. Using `INSERT`, add a new row to the product_units table (with an updated timestamp).
This can be any product you desire (e.g. add another record for Apple Pie). */


INSERT INTO product_units (product_id, product_name, product_size, product_category_id, product_qty_type, snapshot_timestamp) VALUES (100, 'Mango Pie', 'Large', 1, 'unit', CURRENT_TIMESTAMP);

-- DELETE
/* 1. Delete the older record for the whatever product you added.

HINT: If you don't specify a WHERE clause, you are going to have a bad time.*/

DELETE FROM product_units WHERE product_id = 100 AND product_name = 'Mango Pie';


-- UPDATE
Expand All @@ -128,6 +215,39 @@ Finally, make sure you have a WHERE statement to update the right row,
you'll need to use product_units.product_id to refer to the correct row within the product_units table.
When you have all of these components, you can run the update statement. */



ALTER TABLE product_units ADD current_quantity INT;


/*Determining last single quantity with a sum() per product and coalesce */
SELECT *, COALESCE(
(SELECT SUM(vi.quantity)
FROM vendor_inventory vi
WHERE vi.product_id = pu.product_id
AND vi.market_date =
(SELECT MAX(vi2.market_date)
FROM vendor_inventory vi2
WHERE vi2.product_id = pu.product_id
)
),
0)
FROM product_units pu
WHERE pu.product_qty_type = 'unit';


/*UPDATE statement with WHERE clause */

UPDATE product_units AS pu
SET current_quantity =
COALESCE(
(SELECT SUM(vi.quantity)
FROM vendor_inventory vi
WHERE vi.product_id = pu.product_id
AND vi.market_date =
(SELECT MAX(vi2.market_date)
FROM vendor_inventory vi2
WHERE vi2.product_id = pu.product_id
)
),
0)
WHERE pu.product_qty_type = 'unit';