Assignment one

02_activities/assignments/DC_Cohort/Assignment1.md

@@ -211,3 +211,9 @@ Consider, for example, concepts of fariness, inequality, social structures, marg
 ```
 Your thoughts...
 ```
+
+The issues discussed here are disapointing but frequent issuess in databasing. A lot of variables are continuous, changing, and messy, and that inevitably means it is difficult to describe them using discrete bins. This effort for categorization becomes even more complex when the nuances of human social systems are overlain on them. Even relatively common situations like children born out of wedlock or who were orphaned are unable to be categorized by the system. The situation is made worse by the necessity of having a functioning ID card, where people cannot use basic services without one. It demonstrates an unfortunate mix of a database engineered too rigidly, and a social system too dependent on reality conforming to a specific mold.
+
+It reminds me of a similar (though much less serious) situation I dealt with at my place of work. I volunteered here for several years while in school and was integrated into the various computer and security systems as a volunteer, and recently obtained a position as staff. The systems within the network are not all integrated with each other and that meant that when my status was updated to staff and associated privelages changed in one, other systems would flag a silent error due to the missmatch and I was barred from the whole network without explanation. It was a situation that the business hadn't encountered before and no one had thought about ensuring a person's status can change after joining the network, and that various systems may not respond properly. It was fortunately an easy fix once identified, but demonstrates yet another learning opportunity for system flexibility.
+
+The big take-away from the article is to ensure that databases are flexible and able to accomodate future changes. Most of these future changes are unpredictable until they are encountered, and protocols for flexibility need to be considered early on. I argue it also demonstrates that the initial set-up of the system should be associated with a proof-of-concept to make sure the most frequently encountered edge cases are considered. For example, constructing a database on the geneology of millions of people will inevitably encounter cases of single parents or orphans, and procedures to handle those situations must be considered.

02_activities/assignments/DC_Cohort/assignment1.sql

@@ -6,19 +6,19 @@
 --SELECT
 /* 1. Write a query that returns everything in the customer table. */
 --QUERY 1
-
-
-
+SELECT * 
+FROM customer;
 
 --END QUERY
 
 
 /* 2. Write a query that displays all of the columns and 10 rows from the customer table, 
 sorted by customer_last_name, then customer_first_ name. */
 --QUERY 2
-
-
-
+SELECT * 
+FROM customer
+ORDER BY customer_last_name,customer_first_name
+LIMIT 10;
 
 --END QUERY
 
@@ -27,24 +27,25 @@ sorted by customer_last_name, then customer_first_ name. */
 /* 1. Write a query that returns all customer purchases of product IDs 4 and 9. 
 Limit to 25 rows of output. */
 --QUERY 3
-
-
-
+SELECT *
+FROM customer_purchases
+WHERE product_id IN (4, 9) -- There are no products with product_id of 9?...
+LIMIT 25;
 
 --END QUERY
 
 
-
 /*2. Write a query that returns all customer purchases and a new calculated column 'price' (quantity * cost_to_customer_per_qty), 
 filtered by customer IDs between 8 and 10 (inclusive) using either:
 	1.  two conditions using AND
 	2.  one condition using BETWEEN
 Limit to 25 rows of output.
 */
 --QUERY 4
-
-
-
+SELECT *
+,(quantity*cost_to_customer_per_qty) AS price
+FROM customer_purchases
+WHERE customer_id BETWEEN 8 and 10;
 
 --END QUERY
 
@@ -55,9 +56,13 @@ Using the product table, write a query that outputs the product_id and product_n
 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.” */
 --QUERY 5
+SELECT * FROM product; -- look at the product table
 
-
-
+SELECT product_id,product_name
+,CASE WHEN product_qty_type = 'unit' THEN 'unit'
+ELSE 'bulk'
+END AS prod_qty_type_condensed
+FROM product;
 
 --END QUERY
 
@@ -66,8 +71,14 @@ if the product_qty_type is “unit,” and otherwise displays the word “bulk.
 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. */
 --QUERY 6
-
-
+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;
 
 
 --END QUERY
@@ -78,9 +89,16 @@ contains the word “pepper” (regardless of capitalization), and otherwise out
 vendor_id field they both have in common, and sorts the result by market_date, then vendor_name.
 Limit to 24 rows of output. */
 --QUERY 7
+SELECT * FROM vendor; -- look at the vendor table
+SELECT * FROM vendor_booth_assignments; -- look at the table
 
-
-
+SELECT * -- I THINK THIS WORKED?.....
+FROM vendor
+INNER JOIN vendor_booth_assignments
+	ON vendor.vendor_id = vendor_booth_assignments.vendor_id
+ORDER BY vendor_booth_assignments.market_date,
+vendor.vendor_name
+LIMIT 24;
 
 --END QUERY
 
@@ -92,8 +110,18 @@ Limit to 24 rows of output. */
 /* 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. */
 --QUERY 8
-
-
+--This query requires joining two tables using an aggregate function, and use the HAVING keyword
+SELECT
+v.vendor_id
+,v.vendor_name -- this pulls vendor_name from vendor to list with vendor_id and booth_rental_count
+,COUNT(vba.vendor_id) AS booth_rental_count -- count instances of vendor_id as a new column called booth_rental_count
+FROM vendor v
+JOIN vendor_booth_assignments vba
+	ON v.vendor_id = vba.vendor_id
+GROUP BY
+	v.vendor_id
+	,v.vendor_name
+HAVING COUNT(vba.vendor_id) > 0; -- Specify this is done for vendor_id values greater than 0, though the code still runs without it.
 
 
 --END QUERY
@@ -106,8 +134,22 @@ 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. */
 --QUERY 9
 
-
-
+SELECT 
+    c.customer_id
+    ,c.customer_first_name
+    ,c.customer_last_name
+    ,SUM(p.quantity * p.cost_to_customer_per_qty) AS total_spent
+FROM customer c
+JOIN customer_purchases p
+    ON c.customer_id = p.customer_id
+GROUP BY 
+    c.customer_id
+    ,c.customer_first_name
+    ,c.customer_last_name
+HAVING SUM(p.quantity * p.cost_to_customer_per_qty) > 2000
+ORDER BY 
+    c.customer_last_name
+    ,c.customer_first_name;
 
 --END QUERY
 
@@ -124,8 +166,21 @@ When inserting the new vendor, you need to appropriately align the columns to be
 VALUES(col1,col2,col3,col4,col5) 
 */
 --QUERY 10
+CREATE TABLE temp.new_vendor AS
+SELECT *
+FROM vendor;
+
+SELECT *
+FROM vendor
+
+SELECT *
+FROM temp.new_vendor;
 
+INSERT INTO temp.new_vendor
+VALUES (10, 'Thomas Superfood Store', 'Fresh Focused', 'Thomas', 'Rosenthal');
 
+SELECT *
+FROM temp.new_vendor;
 
 
 --END QUERY
@@ -138,8 +193,15 @@ HINT: you might need to search for strfrtime modifers sqlite on the web to know
 and year are! 
 Limit to 25 rows of output. */
 --QUERY 11
+SELECT *
+FROM customer_purchases;
 
-
+SELECT
+customer_id,
+strftime('%m', market_date) AS month
+,strftime('%Y', market_date) AS year
+FROM customer_purchases
+LIMIT 25;
 
 
 --END QUERY
@@ -152,8 +214,13 @@ HINTS: you will need to AGGREGATE, GROUP BY, and filter...
 but remember, STRFTIME returns a STRING for your WHERE statement...
 AND be sure you remove the LIMIT from the previous query before aggregating!! */
 --QUERY 12
-
-
+SELECT
+customer_id
+,SUM(quantity * cost_to_customer_per_qty) AS total_spent
+FROM customer_purchases
+WHERE strftime('%m', market_date) = '04'
+AND strftime('%Y', market_date) = '2022'
+GROUP BY customer_id;
 
 
 --END QUERY