UofT-DSI | SQL - Assignment 1

02_activities/assignments/Cohort_8/FarmersMarket-DB-ER-Diagram-Mermaid.mmd

@@ -0,0 +1,92 @@
+---
+config:
+  layout: elk
+---
+erDiagram
+  POSTAL_DATA ||--o{ CUSTOMER : "fk_postal_code → postal_code_3"
+  PRODUCT_CATEGORY ||--o{ PRODUCT : "fk_product_product_category1"
+  VENDOR ||--o{ VENDOR_INVENTORY : "fk_vendor_inventory_vendor1"
+  PRODUCT ||--o{ VENDOR_INVENTORY : "product_id (FK)"
+  MARKET_DATE_INFO ||--o{ VENDOR_INVENTORY : "market_date (PK part)"
+  VENDOR ||--o{ VENDOR_BOOTH_ASSIGNMENTS : "vendor_id_fk"
+  BOOTH  ||--o{ VENDOR_BOOTH_ASSIGNMENTS : "booth_number_fk"
+  MARKET_DATE_INFO ||--o{ VENDOR_BOOTH_ASSIGNMENTS : "market_date_fk"
+  CUSTOMER ||--o{ CUSTOMER_PURCHASES : "fk_customer_purchases_customer1"
+  VENDOR_INVENTORY ||--o{ CUSTOMER_PURCHASES : "fk_customer_purchases_vendor_inventory1"
+  BOOTH {
+    int booth_number PK
+    varchar booth_price_level
+    varchar booth_description
+    varchar booth_type
+  }
+  CUSTOMER {
+    int customer_id PK
+    nvarchar customer_first_name
+    nvarchar customer_last_name
+    char customer_postal_code FK
+  }
+  CUSTOMER_PURCHASES {
+    int product_id PK, FK
+    int vendor_id PK, FK
+    date market_date PK, FK
+    int customer_id PK, FK
+    time transaction_time PK
+    decimal quantity
+    decimal cost_to_customer_per_qty
+  }
+  MARKET_DATE_INFO {
+    date market_date PK
+    varchar market_day
+    varchar market_week
+    varchar market_year
+    varchar market_start_time
+    varchar market_end_time
+    blob special_notes
+    varchar market_season
+    varchar market_min_temp
+    varchar market_max_temp
+    int market_rain_flag
+    int market_snow_flag
+  }
+  POSTAL_DATA {
+    char postal_code_3 PK
+    nvarchar city
+    nvarchar district
+    int population
+    int median_household_income
+    float percent_under_14
+    float percent_over_65
+    int labour_force
+    float latitude
+    float longitude
+  }
+  PRODUCT {
+    int product_id PK
+    int product_category_id PK, FK
+    varchar product_name
+    varchar product_size
+    varchar product_qty_type
+  }
+  PRODUCT_CATEGORY {
+    int product_category_id PK
+    varchar product_category_name
+  }
+  VENDOR {
+    int vendor_id PK
+    varchar vendor_name
+    varchar vendor_type
+    varchar vendor_owner_first_name
+    varchar vendor_owner_last_name
+  }
+  VENDOR_BOOTH_ASSIGNMENTS {
+    int vendor_id PK, FK
+    int booth_number PK, FK
+    date market_date PK, FK
+  }
+  VENDOR_INVENTORY {
+    date market_date PK, FK
+    int vendor_id PK, FK
+    int product_id PK, FK
+    decimal quantity
+    decimal original_price
+  }

02_activities/assignments/Cohort_8/assignment1.sql

@@ -5,17 +5,23 @@
 --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. */
 
-
+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 customer IDs between 8 and 10 (inclusive) using either:
@@ -24,29 +30,69 @@ filtered by customer IDs between 8 and 10 (inclusive) using either:
 */
 -- option 1
 
+SELECT 
+    *,
+    (quantity * cost_to_customer_per_qty) AS price
+FROM customer_purchases
+WHERE customer_id >= 8 
+  AND customer_id <= 10;
 
 -- option 2
-
+SELECT 
+    *,
+    (quantity * cost_to_customer_per_qty) AS price
+FROM customer_purchases
+WHERE customer_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 
+    v.vendor_id,
+    v.vendor_name,
+    v.vendor_type,
+    v.vendor_owner_first_name,
+    v.vendor_owner_last_name,
+    vba.booth_number,
+    vba.market_date
+FROM vendor AS v
+INNER JOIN vendor_booth_assignments AS vba
+    ON v.vendor_id = vba.vendor_id
+ORDER BY v.vendor_name, vba.market_date;
 
 
 
@@ -56,6 +102,11 @@ 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 
@@ -64,7 +115,23 @@ 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 AS c
+INNER JOIN customer_purchases AS 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
 /* 1. Insert the original vendor table into a temp.new_vendor and then add a 10th vendor: 
@@ -78,14 +145,35 @@ When inserting the new vendor, you need to appropriately align the columns to be
 VALUES(col1,col2,col3,col4,col5) 
 */
 
-
+CREATE TEMPORARY TABLE 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'
+);
 
 -- Date
 /*1. Get the customer_id, month, and year (in separate columns) of every purchase in the customer_purchases table.
 
 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. 
@@ -94,3 +182,10 @@ 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('%m', market_date) = '04' 
+  AND STRFTIME('%Y', market_date) = '2022'
+GROUP BY customer_id;