this_is_assignment_2

02_activities/assignments/Microcredential_Cohort/Assignment2.md

@@ -57,6 +57,9 @@ The store wants to keep customer addresses. Propose two architectures for the CU
 
 ```
 Your answer...
+
+One architecture would contain coulmns as customer_id, address, city, province, postal_code and country. if customer moves, we can simply update the address but will lost any previopus record (TYPE 1)
+Second architecture would be to include above coulomns witha ddition 3 columns, start_date, end_date as well as current_status. when the address changes, a new address can be added and the end date will be the start date of the new address and if current_status is 1 it will mean that address is valid, if 0 it means that is the old record. (Type 2) 
 ```
 
 ***

02_activities/assignments/Microcredential_Cohort/assignment2.sql

@@ -22,13 +22,12 @@ 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. */
 --QUERY 1
-
-
-
+Select 
+COALESCE(product_name, '') || ', ' || COALESCE(product_size, '') || ' (' || COALESCE(product_qty_type, 'unit') || ')'
+From product
 
 --END QUERY
 
-
 --Windowed Functions
 /* 1. Write a query that selects from the customer_purchases table and numbers each customer’s  
 visits to the farmer’s market (labeling each market date with a different number). 
@@ -41,8 +40,13 @@ HINT: One of these approaches uses ROW_NUMBER() and one uses DENSE_RANK().
 Filter the visits to dates before April 29, 2022. */
 --QUERY 2
 
-
-
+SELECT customer_id, market_date,
+row_number()OVER(
+PARTITION BY customer_id
+ORDER BY market_date ASC
+) as 'customer_visit_number'
+FROM customer_purchases
+WHERE market_date < '2022-04-29'
 
 --END QUERY
 
@@ -53,8 +57,16 @@ only the customer’s most recent visit.
 HINT: Do not use the previous visit dates filter. */
 --QUERY 3
 
-
-
+SELECT *
+FROM(
+	Select customer_id, market_date, 
+	ROW_NUMBER() OVER 
+	(PARTITION BY customer_id 
+	ORDER BY market_date DESC
+	) AS "customer_visit_number"
+	From customer_purchases
+) AS visits
+Where "customer_visit_number" = 1
 
 --END QUERY
 
@@ -66,8 +78,13 @@ You can make this a running count by including an ORDER BY within the PARTITION
 Filter the visits to dates before April 29, 2022. */
 --QUERY 4
 
-
-
+Select customer_id, product_id, market_date, 
+COUNT(product_id) OVER 
+(PARTITION BY customer_id, product_id 
+ORDER BY market_date
+) AS purchase_count
+From customer_purchases
+Where market_date < '2022-04-29'
 
 --END QUERY
 
@@ -85,17 +102,22 @@ 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. */
 --QUERY 5
 
-
-
+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
 
 --END QUERY
 
 
 /* 2. Filter the query to show any product_size value that contain a number with REGEXP. */
 --QUERY 6
-
-
-
+Select product_name, product_size
+From product
+Where product_size REGEXP '[0-9]'
 
 --END QUERY
 
@@ -111,9 +133,42 @@ HINT: There are a possibly a few ways to do this query, but if you're struggling
 with a UNION binding them. */
 --QUERY 7
 
-
-
-
+WITH daily_sales AS (
+    SELECT
+        market_date,
+        SUM(quantity * cost_per_quantity) AS total_sales
+    FROM customer_purchases
+    GROUP BY market_date
+),
+
+ranked_sales AS (
+    SELECT
+        market_date,
+        total_sales,
+        ROW_NUMBER() OVER (
+            ORDER BY total_sales DESC
+        ) AS best_day,
+        ROW_NUMBER() OVER (
+            ORDER BY total_sales ASC
+        ) AS worst_day
+    FROM daily_sales
+)
+
+SELECT
+    market_date,
+    total_sales,
+    'best day' AS day_type
+FROM ranked_sales
+WHERE best_day = 1
+
+UNION
+
+SELECT
+    market_date,
+    total_sales,
+    'worst day' AS day_type
+FROM ranked_sales
+WHERE worst_day = 1;
 --END QUERY
 
 
@@ -132,9 +187,16 @@ How many customers are there (y).
 Before your final group by you should have the product of those two queries (x*y).  */
 --QUERY 8
 
-
-
-
+SELECT v.vendor_name, p.product_name, 
+SUM(vi.original_price * 5) AS total_sales
+FROM vendor_inventory vi
+JOIN vendor AS v 
+ON vi.vendor_id = v.vendor_id
+JOIN product AS p
+ON vi.product_id = p.product_id
+CROSS JOIN (
+	SELECT COUNT(DISTINCT customer_id) AS customer_count FROM customer) AS c
+GROUP BY v.vendor_name, p.product_name
 --END QUERY
 
 
@@ -144,20 +206,20 @@ 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`. */
 --QUERY 9
-
-
-
+CREATE TABLE product_units AS
+Select *, 
+CURRENT_TIMESTAMP AS snapshot_timestamp
+FROM product
+Where product_qty_type = 'unit'	
 
 --END QUERY
 
 
 /*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). */
 --QUERY 10
-
-
-
-
+INSERT INTO product_units (product_id, product_name, product_size, product_category_id, product_qty_type, snapshot_timestamp)
+VALUES (257, 'Apple Pie', '1 pie', '10', 'unit', CURRENT_TIMESTAMP);
 --END QUERY
 
 
@@ -167,12 +229,11 @@ This can be any product you desire (e.g. add another record for Apple Pie). */
 HINT: If you don't specify a WHERE clause, you are going to have a bad time.*/
 --QUERY 11
 
-
-
+DELETE FROM product_units
+WHERE product_id = 7;
 
 --END QUERY
 
-
 -- UPDATE
 /* 1.We want to add the current_quantity to the product_units table. 
 First, add a new column, current_quantity to the table using the following syntax.
@@ -190,9 +251,29 @@ 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. */
 --QUERY 12
+ALTER TABLE product_units
+ADD current_quantity INT;
 
-
-
+UPDATE product_units
+SET current_quantity = COALESCE(
+    (
+        SELECT quantity
+        FROM (
+            SELECT
+                product_id,
+                quantity,
+                market_date,
+                ROW_NUMBER() OVER (
+                    PARTITION BY product_id
+                    ORDER BY market_date DESC
+                ) AS rn
+            FROM vendor_inventory
+        ) AS latest
+        WHERE latest.product_id = product_units.product_id
+          AND latest.rn = 1
+    ),
+    0
+);
 
 --END QUERY