diff --git a/02_activities/assignments/EntityRelationshipDiagram_Chun-YuanChen.pdf b/02_activities/assignments/EntityRelationshipDiagram_Chun-YuanChen.pdf new file mode 100644 index 000000000..d46e5d000 Binary files /dev/null and b/02_activities/assignments/EntityRelationshipDiagram_Chun-YuanChen.pdf differ diff --git a/02_activities/assignments/assignment1.sql b/02_activities/assignments/assignment1.sql index 2e89fa7af..f327d4ccb 100644 --- a/02_activities/assignments/assignment1.sql +++ b/02_activities/assignments/assignment1.sql @@ -1,25 +1,34 @@ + +--Module: SQL +--Name: Chun-Yuan Chen +--Assignment: 1 +--Sections: 2 & 3 + + /* ASSIGNMENT 1 */ /* SECTION 2 */ --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; /* Note: I found no records with product_id = 9 in the dataset. */ -- 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: @@ -27,10 +36,14 @@ filtered by vendor IDs between 8 and 10 (inclusive) using either: 2. one condition using BETWEEN */ -- option 1 - +SELECT *, quantity * cost_to_customer_per_qty AS price +FROM customer_purchases +WHERE vendor_id >= 8 AND vendor_id <= 10; /* Note: I found no records with vendor_id = 9 or 10 in the dataset. */ -- option 2 - +SELECT *, quantity * cost_to_customer_per_qty AS price +FROM customer_purchases +WHERE vendor_id BETWEEN 8 AND 10; /* Note: Just curious myself, unsure if BETWEEN can be set as inclusive or exclusive like other languages. */ --CASE @@ -38,36 +51,61 @@ filtered by vendor IDs between 8 and 10 (inclusive) using either: 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' + WHEN product_qty_type IS NULL THEN NULL /* Note: I added this command in order to account for NULL in the product_qty_type column. */ + 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' + WHEN product_qty_type IS NULL THEN NULL + ELSE 'bulk' + END AS prod_qty_type_condensed, + CASE + WHEN 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 v.*, vba.booth_number, vba.market_date +FROM vendor v + INNER JOIN vendor_booth_assignments vba ON v.vendor_id = vba.vendor_id +ORDER BY v.vendor_name ASC, vba.market_date ASC; /* Note: I added ASC just in case.*/ /* SECTION 3 */ + -- AGGREGATE /* 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 /* Note: I determined using an asterisk after confirming no redundant or empty rows.*/ +FROM vendor_booth_assignments +GROUP BY vendor_id; /* 2. The Farmer’s Market Customer Appreciation Committee wants to give a bumper sticker to everyone who has ever spent more than $2000 at the market. Write a query that generates a list 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 + INNER JOIN customer_purchases cp ON c.customer_id = cp.customer_id +GROUP BY c.customer_id +HAVING total_spent > 2000 +ORDER BY c.customer_last_name ASC, c.customer_first_name ASC; --Temp Table @@ -81,7 +119,15 @@ When inserting the new vendor, you need to appropriately align the columns to be -> To insert the new row use VALUES, specifying the value you want for each column: VALUES(col1,col2,col3,col4,col5) */ +DROP TABLE IF EXISTS temp.new_vendor; + +CREATE TABLE temp.new_vendor AS +SELECT * FROM vendor; + +INSERT INTO new_vendor (vendor_id, vendor_name, vendor_type, vendor_owner_first_name, vendor_owner_last_name) +VALUES (10, 'Thomass Superfood Store', 'Fresh Focused', 'Thomas', 'Rosenthal'); +SELECT * FROM new_vendor; -- Date @@ -89,12 +135,18 @@ 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, strftime('%m', market_date) AS month, strftime('%Y', market_date) AS year, SUM(quantity * cost_to_customer_per_qty) AS total_spent /* Note: The last one for the aggregate purpose. */ +FROM customer_purchases +WHERE month = '04' AND year = '2022' /* Note: Here for the filter purpose. */ +GROUP BY customer_id; /* Note: Here for the group by purpose. */ + +/* Completed! */