Assignment two

02_activities/assignments/Cohort_8/assignment1.sql

@@ -175,7 +175,7 @@ SELECT *
 FROM vendor
 
 INSERT INTO temp.new_vendor (vendor_id, vendor_name, vendor_owner_first_name, vendor_owner_last_name, vendor_type)
-VALUES ('10', 'Thomass Superfood Store','Fresh Focused','Thomas','Rosenthal'); --
+VALUES ('10', 'Thomass Superfood Store','Fresh Focused','Thomas','Rosenthal'); --complete
 
 -- Date
 /*1. Get the customer_id, month, and year (in separate columns) of every purchase in the customer_purchases table.

02_activities/assignments/Cohort_8/assignment2.sql

@@ -7,7 +7,7 @@ We tell them, no problem! We can produce a list with all of the appropriate deta
 
 Using the following syntax you create our super cool and not at all needy manager a list:
 
-SELECT 
+SELECT
 product_name || ', ' || product_size|| ' (' || product_qty_type || ')'
 FROM product
 
@@ -21,7 +21,12 @@ 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
+    COALESCE(product_name, '') || ', ' ||
+    COALESCE(product_size, '') ||
+    ' (' || COALESCE(product_qty_type, 'unit') || ')'
+        AS product_summary
+FROM product;
 
 
 --Windowed Functions
@@ -34,17 +39,51 @@ 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 ASC
+	) as customer_visit_order
 
+FROM customer_purchases;
 
 /* 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. */
 
+DROP TABLE IF EXISTS customer_first_visit;
+
+CREATE TEMP TABLE customer_first_visit AS
+	SELECT
+		customer_id, 
+		market_date,
+
+		dense_rank() OVER(
+			PARTITION BY customer_id 
+			ORDER BY market_date DESC
+			) as customer_visit_order
 
+	FROM customer_purchases;
+
+SELECT*
+FROM customer_first_visit
+WHERE customer_visit_order=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,
+
+
+COUNT(*) OVER (
+	PARTITION BY customer_id, product_id)
+	AS count_of_product_per_customer
+FROM customer_purchases;
 
 
 -- String manipulations
@@ -59,11 +98,27 @@ 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 NULL
+	ELSE TRIM(substr(
+		product_name,
+		instr(product_name,'-')+1 -- starts right after hyphen
+	))
+	END as description
+FROM product;
 
 /* 2. Filter the query to show any product_size value that contain a number with REGEXP. */
 
 
+SELECT
+	product_size
+		FROM product
+	WHERE product_size REGEXP '[0-9]'
+;
+
 
 -- UNION
 /* 1. Using a UNION, write a query that displays the market dates with the highest and lowest total sales.
@@ -75,8 +130,39 @@ 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. */
 
-
-
+DROP TABLE IF EXISTS sales_per_market_day;
+
+CREATE TEMP TABLE sales_per_market_day as
+
+	SELECT
+		market_date
+		,SUM(quantity*cost_to_customer_per_qty) as total_sales
+		FROM customer_purchases
+		Group BY market_date;
+
+WITH ranked as (
+	SELECT
+		market_date,
+		total_sales,
+		RANK() OVER (ORDER BY total_sales DESC) as rank_desc,
+		RANK() OVER (ORDER BY total_sales ASC) as rank_asc
+				FROM sales_per_market_day)
+
+SELECT
+	market_date,
+	total_sales,
+	'highest' AS day_type
+FROM ranked
+WHERE rank_desc = 1
+
+UNION
+
+SELECT
+	market_date,
+	total_sales,
+	'lowest' AS day_type
+FROM ranked
+WHERE rank_asc = 1;
 
 /* SECTION 3 */
 
@@ -91,27 +177,59 @@ 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).  */
 
-
-
+SELECT
+    v.vendor_name,
+    p.product_name,
+    SUM(5 * vi.original_price) AS total_revenue
+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 customer c
+GROUP BY
+    v.vendor_name,
+    p.product_name
+ORDER BY
+    v.vendor_name,
+    p.product_name;
+
+
 -- INSERT
 /*1.  Create a new table "product_units". 
 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`. */
 
+DROP TABLE IF EXISTS product_units;
 
+CREATE TABLE product_units AS
+SELECT 
+	product_id,
+	product_name,
+	product_size,
+	product_category_id,
+	product_qty_type,
+	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]
+VALUES (24, Yellow Potatoes, small, 1, lbs)
 
 -- 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 = (
+		SELECT max_product_id FROM (SELECT MAX(product_id) AS max_product_id 
+		FROM product_units)
+		);
 
 -- UPDATE
 /* 1.We want to add the current_quantity to the product_units table. 
@@ -131,5 +249,14 @@ Finally, make sure you have a WHERE statement to update the right row,
 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 = (
+    SELECT COALESCE(quantity, 0)
+    FROM vendor_inventory vi
+    WHERE vi.product_id = product_units.product_id
+    ORDER BY market_date DESC
+    LIMIT 1
+);