Assignment-two

02_activities/assignments/assignment1.sql

@@ -5,21 +5,25 @@
 --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
 
+select * from customer_purchases where product_id = 4 or product_id = 9;
 
 -- option 2
 
-
+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), 
 filtered by vendor IDs between 8 and 10 (inclusive) using either:
@@ -28,30 +32,50 @@ filtered by vendor IDs between 8 and 10 (inclusive) using either:
 */
 -- option 1
 
+select *, (quantity * cost_to_customer_per_qty) as price from customer_purchases
+where vendor_id >= 8 and vendor_id <= 10;
 
 -- option 2
 
-
+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 v
+inner join vendor_booth_assignments vba on v.vendor_id = vba.vendor_id
+order by v.vendor_name, vba.market_date;
 
 
 /* SECTION 3 */
@@ -60,6 +84,9 @@ 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 
@@ -68,6 +95,14 @@ 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
@@ -82,6 +117,12 @@ When inserting the new vendor, you need to appropriately align the columns to be
 VALUES(col1,col2,col3,col4,col5) 
 */
 
+create table temp.new_vendor as
+select * from vendor;
+
+insert into temp.new_vendor (vendor_id, vendor_name, vendor_type, vendor_owner_first_name, vendor_owner_last_name)
+values (10, 'Thomass Superfood Store', 'Fresh Focused store', 'Thomas', 'Rosenthal');
+
 
 
 -- Date
@@ -90,11 +131,19 @@ VALUES(col1,col2,col3,col4,col5)
 HINT: you might need to search for strfrtime modifers sqlite on the web to know what the modifers for month 
 and year are! */
 
-
+select customer_id,
+       strftime('%m', market_date) as month,
+       strftime('%Y', market_date) as year
+from customer_purchases;
 
 /* 2. Using the previous query as a base, determine how much money each customer spent in April 2022. 
 Remember that money spent is quantity*cost_to_customer_per_qty. 
 
 HINTS: you will need to AGGREGATE, GROUP BY, and filter...
 but remember, STRFTIME returns a STRING for your WHERE statement!! */
 
+select customer_id, sum(quantity * cost_to_customer_per_qty) as total_spent
+from customer_purchases
+where strftime('%Y', market_date) = '2022'
+  and strftime('%m', market_date) = '04'
+group by customer_id;

02_activities/assignments/assignment2.sql

@@ -20,6 +20,13 @@ 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 * from product
+where product_size is null or product_qty_type is null;
+
+select product_name || ', ' || 
+    coalesce(product_size, '') || ' (' || 
+    coalesce(product_qty_type, 'unit') || ')' as formatted_product
+from product;
 
 
 --Windowed Functions
@@ -32,17 +39,37 @@ 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,
+    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 * from (
+    select customer_id, market_date,
+        row_number() over (
+            partition by customer_id
+            order by market_date desc
+        ) AS visit_number
+    from customer_purchases
+) 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, quantity, cost_to_customer_per_qty,
+    count(*) over (
+        partition by customer_id, product_id
+    ) as times_purchased
+from customer_purchases;
 
 
 -- String manipulations
@@ -57,10 +84,18 @@ 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_id, product_name,
+    trim(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 product_id, product_name, product_size from product
+where product_size regexp '[0-9]';
 
 
 -- UNION
@@ -73,6 +108,26 @@ 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. */
 
+-- Get highest and lowest sales days
+select market_date, total_sales from (
+    select 
+        market_date,
+        SUM(quantity * cost_to_customer_per_qty) as total_sales
+    from customer_purchases
+    group by market_date
+    order by total_sales desc
+    limit 1
+)
+union
+select market_date, total_sales from (
+    select 
+        market_date,
+        SUM(quantity * cost_to_customer_per_qty) as total_sales
+    from customer_purchases
+    group by market_date
+    order by total_sales asc
+    limit 1
+);
 
 
 
@@ -89,6 +144,13 @@ 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,
+    count(distinct c.customer_id) * 5 * vi.original_price as total_revenue
+from vendor_inventory vi
+cross join customer c
+join vendor v on vi.vendor_id = v.vendor_id
+join product p on vi.product_id = p.product_id
+group by v.vendor_name, p.product_name, vi.original_price;
 
 
 -- INSERT
@@ -97,18 +159,30 @@ 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 the new table with the extra column
+create table product_units as
+select product_id, product_name, product_size, product_qty_type,
+    product_category_id, 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_qty_type,
+    product_category_id, snapshot_timestamp
+)
+values (999, 'Apple Pie', '12"', '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_name = 'apple pie' and snapshot_timestamp is null;
 
 
 -- UPDATE
@@ -128,6 +202,21 @@ 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 T1.quantity
+     from vendor_inventory as T1
+     where T1.product_id = product_units.product_id
+     and T1.market_date = (
+         select MAX(T2.market_date)
+         from vendor_inventory as T2
+         where T2.product_id = product_units.product_id
+     )
+    ), 0
+);