Assignment two

02_activities/assignments/Assignment2.md

@@ -56,7 +56,9 @@ The store wants to keep customer addresses. Propose two architectures for the CU
 ```
 Your answer...
 ```
+The Customer Address table that will retain changes is type 2 SCD where apart from storing the Customer_ID,Customer_Name,Customer_Address_line_1 , Customer_Address_Line_2 ,City, State,Country and Pincode, the table would also have columns to track changes made to the record, such as Customer_Address_Active_Flag, Customer_Addr_Start_Date and Customer_Addr_End_date.
 
+The Customer Address table that will overwrite changes is type 1 SCD where each record will be overwritten with columns such as the Customer_Name,Customer_Address_line_1 , Customer_Address_Line_2 ,City, State,Country and Pincode.The CustomerID column would be the primary key that cannot be overwritten.
 ***
 
 ## Section 2:

02_activities/assignments/assignment2.sql

@@ -1,4 +1,4 @@
-/* ASSIGNMENT 2 */
+/* ASSIGNMENT 2 Sucharitha S*/
 /* SECTION 2 */
 
 -- COALESCE
@@ -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 +35,20 @@ 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 market_date,customer_id, row_number() over (partition by customer_id order by market_Date asc) as market_visit from customer_purchases
+order by customer_id;
 
 /* 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 x.customer_id, x.market_Date as recent_market_visit from
+(select market_date,customer_id, row_number() over (partition by customer_id order by market_Date desc) as market_visit_count from customer_purchases) x
+where x.market_visit_count = 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 purchased_count from customer_purchases;
 
 -- String manipulations
 /* 1. Some product names in the product table have descriptions like "Jar" or "Organic". 
@@ -57,10 +62,13 @@ 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,
+iif(instr(product_name,'-')=0,null,rtrim(ltrim(substr(product_name,INSTR(product_name,'-')+1))))as description
+from product;
 
 /* 2. Filter the query to show any product_size value that contain a number with REGEXP. */
 
+select * from product where product_size  regexp ( '\d');
 
 
 -- UNION
@@ -72,7 +80,15 @@ HINT: There are a possibly a few ways to do this query, but if you're struggling
 "best day" and "worst day"; 
 3) Query the second temp table twice, once for the best day, once for the worst day, 
 with a UNION binding them. */
-
+with sales_rank as (
+select x.market_date, x.total_sales,
+dense_rank() over (order by x.total_sales asc) as sales_rank_low, 
+dense_rank() over (order by x.total_sales desc) as sales_rank_high from  
+(select sum(quantity * cost_to_customer_per_qty) as total_sales, market_date from customer_purchases group by market_date) x
+) 
+select market_date, total_sales from sales_rank where sales_rank_low = 1 
+UNION
+select market_date, total_sales from sales_rank where sales_rank_high = 1;
 
 
 
@@ -88,7 +104,17 @@ 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).  */
-
+with cr_join_op as
+(
+select distinct vi.vendor_id, vi.product_id, v.vendor_name, p.product_name, vi.original_price, c.customer_id from 
+vendor_inventory vi inner join vendor v on
+vi.vendor_id = v.vendor_id
+inner join product p 
+on p.product_id = vi.product_id 
+cross join customer c
+)
+select vendor_name,product_name,sum(original_price * 5)total_sales from 
+cr_join_op group by vendor_name,product_name
 
 
 -- INSERT
@@ -97,19 +123,26 @@ 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 temp.product_units;
+CREATE TEMP TABLE product_units AS 
+	SELECT * FROM product where product_qty_type = 'unit';
+
+ALTER TABLE temp.product_units
+ADD snapshot_timestamp CURRENT_TIMESTAMP;
 
+SELECT * FROM temp.product_units;
 
 /*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, 'Sweet Corn', 'Ear',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 =24;
 
 -- UPDATE
 /* 1.We want to add the current_quantity to the product_units table. 
@@ -128,6 +161,24 @@ 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 temp.product_units
+ADD current_quantity INT;
 
-
-
+WITH product_last_quantity AS (
+  SELECT 
+    product_id, 
+    COALESCE(quantity, 0) AS quantity
+  FROM (
+    SELECT 
+      product_id, 
+      market_date, 
+      quantity, 
+      ROW_NUMBER() OVER (PARTITION BY product_id ORDER BY market_date DESC) AS rn
+    FROM vendor_inventory
+  ) subquery
+  WHERE rn = 1
+)
+UPDATE product_units
+SET current_quantity = plq.quantity
+FROM product_last_quantity plq
+WHERE product_units.product_id = plq.product_id;