Assignment two submission - Sunday

02_activities/assignments/assignment1.sql

@@ -5,20 +5,33 @@
 --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 1 
+
+--OR 
+SELECT * 
+FROM customer_purchases
+WHERE product_id = 4 OR product_id = 9;
 
 
 -- option 2
 
+--IN
+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), 
@@ -28,30 +41,61 @@ filtered by vendor IDs between 8 and 10 (inclusive) using either:
 */
 -- option 1
 
+--AND
+SELECT *, 
+       quantity * cost_to_customer_per_qty AS price
+FROM customer_purchases
+WHERE vendor_id >= 8 AND vendor_id <= 10;
 
 -- option 2
 
-
+--BETWEEN
+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 * 
+FROM vendor
+INNER JOIN vendor_booth_assignments 
+    ON vendor.vendor_id = vendor_booth_assignments.vendor_id
+ORDER BY vendor.vendor_name, vendor_booth_assignments.market_date;
 
 
 /* SECTION 3 */
@@ -60,14 +104,29 @@ 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 booth_rental_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 total_spent
+FROM customer c
+JOIN customer_purchases 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
@@ -82,7 +141,15 @@ When inserting the new vendor, you need to appropriately align the columns to be
 VALUES(col1,col2,col3,col4,col5) 
 */
 
+DROP TABLE IF EXISTS temp.new_vendor;
+
+CREATE TABLE temp.new_vendor AS
+SELECT * FROM vendor;
+
+ALTER TABLE temp.new_vendor ADD COLUMN vendor_description TEXT;
 
+INSERT INTO temp.new_vendor (vendor_id, vendor_name, vendor_description, vendor_owner_first_name, vendor_owner_last_name)
+VALUES (10, 'Thomass Superfood Store', 'Fresh Focused store', 'Thomas', 'Rosenthal');
 
 -- Date
 /*1. Get the customer_id, month, and year (in separate columns) of every purchase in the customer_purchases table.

02_activities/assignments/assignment2.sql

@@ -20,6 +20,9 @@ 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
@@ -32,18 +35,40 @@ 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(). */
 
-
+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
+) AS unique_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. */
 
-
+FROM (
+  SELECT 
+    customer_id,
+    market_date,
+    DENSE_RANK() OVER (PARTITION BY customer_id ORDER BY market_date DESC) AS visit_number
+  FROM (
+    SELECT DISTINCT customer_id, market_date
+    FROM customer_purchases
+  ) AS unique_visits
+) AS ranked_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 
+  customer_id,
+  product_id,
+  market_date,
+  COUNT(*) OVER (PARTITION BY customer_id, product_id) AS customer_product_purchase_count
+FROM customer_purchases;
 
 -- String manipulations
 /* 1. Some product names in the product table have descriptions like "Jar" or "Organic". 
@@ -57,11 +82,22 @@ 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 
+  product_name,
+  CASE 
+    WHEN INSTR(product_name, '-') > 0 
+    THEN TRIM(SUBSTR(product_name, INSTR(product_name, '-') + 1))
+    ELSE NULL
+  END AS description
+FROM product;
 
 /* 2. Filter the query to show any product_size value that contain a number with REGEXP. */
 
-
+SELECT 
+  product_name,
+  product_size
+FROM product
+WHERE product_size GLOB '*[0-9]*';
 
 -- UNION
 /* 1. Using a UNION, write a query that displays the market dates with the highest and lowest total sales.
@@ -73,7 +109,37 @@ HINT: There are a possibly a few ways to do this query, but if you're struggling
 3) Query the second temp table twice, once for the best day, once for the worst day, 
 with a UNION binding them. */
 
+WITH sales_by_date AS (
+  SELECT 
+    market_date,
+    SUM(quantity * cost_to_customer_per_qty) AS total_sales
+  FROM customer_purchases
+  GROUP BY market_date
+),
+ranked_sales AS (
+  SELECT 
+    market_date,
+    total_sales,
+    RANK() OVER (ORDER BY total_sales DESC) AS best_rank,
+    RANK() OVER (ORDER BY total_sales ASC) AS worst_rank
+  FROM sales_by_date
+)
 
+SELECT 
+  market_date,
+  total_sales,
+  'Best Day' AS day_type
+FROM ranked_sales
+WHERE best_rank = 1
+
+UNION
+
+SELECT 
+  market_date,
+  total_sales,
+  'Worst Day' AS day_type
+FROM ranked_sales
+WHERE worst_rank = 1;
 
 
 /* SECTION 3 */
@@ -89,6 +155,23 @@ Think a bit about the row counts: how many distinct vendors, product names are t
 How many customers are there (y). 
 Before your final group by you should have the product of those two queries (x*y).  */
 
+WITH vendor_products AS (
+  SELECT 
+    v.vendor_name,
+    p.product_name,
+    vi.original_price
+  FROM vendor_inventory vi
+  JOIN vendor v ON vi.vendor_id = v.vendor_id
+  JOIN product p ON vi.product_id = p.product_id
+)
+
+SELECT 
+  vendor_name,
+  product_name,
+  SUM(5 * original_price) AS total_revenue
+FROM vendor_products
+CROSS JOIN customer
+GROUP BY vendor_name, product_name;
 
 
 -- INSERT
@@ -97,18 +180,42 @@ 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 (
+  999,            -- New unique product_id
+  'Apple Pie Supreme', 
+  '1 unit', 
+  3,              -- Category 3 (since it exists)
+  '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.*/
 
+SELECT * FROM product_units WHERE product_name LIKE '%Apple Pie%';
+
+DELETE FROM product_units
+WHERE product_name = 'Apple Pie';
 
 
 -- UPDATE
@@ -128,6 +235,19 @@ 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;
+
+UPDATE product_units
+SET current_quantity = COALESCE((
+    SELECT vi.quantity
+    FROM vendor_inventory vi
+    WHERE vi.product_id = product_units.product_id
+    ORDER BY vi.market_date DESC
+    LIMIT 1
+), 0);
+
+