Assignment two

02_activities/assignments/Assignment2.md

@@ -54,9 +54,9 @@ The store wants to keep customer addresses. Propose two architectures for the CU
 **HINT:** search type 1 vs type 2 slowly changing dimensions. 
 
 ```
-Your answer...
+Architecture 1 overwrites the old address, which would be Type 1. Simpler to build but doesn't retain old addresses, useful for situations where historical data is not important.
 ```
-
+Architecture 2 is able to assign more than one address to a customer and retain their old addresses. This would be Type 2. Helpful for analytical approach as it keeps historical records
 ***
 
 ## Section 2:

02_activities/assignments/assignment2.sql

@@ -20,6 +20,15 @@ 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 || ', ' || product_size|| ' (' || product_qty_type || ')'
+FROM product;
+
+SELECT 
+    COALESCE(product_name, '') || ', ' || 
+    COALESCE(product_size, '') || ' (' || 
+    COALESCE(product_qty_type, 'unit') || ')' AS product_description
+FROM product;
 
 
 --Windowed Functions
@@ -31,18 +40,34 @@ You can either display all rows in the customer_purchases table, with the counte
 each new market date for each customer, or select only the unique market dates per customer 
 (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,
+    ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY market_date) AS visit_number
+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. */
-
+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
+) unique_visits;
 
 
 /* 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 purchase_count,
+    market_date
+FROM customer_purchases;
 
 
 -- String manipulations
@@ -56,11 +81,19 @@ Remove any trailing or leading whitespaces. Don't just use a case statement for
 | Habanero Peppers - Organic | Organic     |
 
 Hint: you might need to use INSTR(product_name,'-') to find the hyphens. INSTR will help split the column. */
-
+SELECT 
+    product_name,
+    TRIM(SUBSTR(product_name, INSTR(product_name, '-') + 1)) AS description
+FROM product
+WHERE INSTR(product_name, '-') > 0;
 
 
 /* 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 REGEXP '[0-9]';
 
 
 -- UNION
@@ -73,7 +106,27 @@ 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. */
 
-
+SELECT market_date, daily_sales
+FROM
+(select market_date
+,quantity*cost_to_customer_per_qty as sales 
+,sum(quantity*cost_to_customer_per_qty) as daily_sales
+,rank()over (order by sum(quantity*cost_to_customer_per_qty)) as sales_rank
+FROM customer_purchases
+GROUP BY market_date)
+WHERE sales_rank = 1
+
+UNION
+
+SELECT market_date, daily_sales
+FROM
+(select market_date
+,quantity*cost_to_customer_per_qty as sales 
+,sum(quantity*cost_to_customer_per_qty) as daily_sales
+,rank()over (order by sum(quantity*cost_to_customer_per_qty)DESC) as sales_rank
+FROM customer_purchases
+GROUP BY market_date)
+WHERE sales_rank = 1;
 
 
 /* SECTION 3 */
@@ -89,27 +142,57 @@ 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, 
+	(5*cp.cost_to_customer_per_qty*c.total_customers) AS 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
+JOIN
+	customer_purchases cp ON p.product_id = cp.product_id
+CROSS JOIN (
+    SELECT COUNT (customer_id) AS total_customers
+    FROM 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 TEMP 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 (27, 'Apple Pie', '10"', 3, '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 = 27;
 
 -- UPDATE
 /* 1.We want to add the current_quantity to the product_units table. 
@@ -129,5 +212,15 @@ 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 = 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);