.env-tp

@@ -1,2 +0,0 @@
-MYSQL_ROOT_PASSWORD=password
-MYSQL_PASSWORD=password

.gitignore

@@ -1,4 +1,3 @@
 /.idea/
 **/target/
 *.iml
-*.env

.tool-versions

@@ -1,3 +1,2 @@
 java temurin-21.0.3+9.0.LTS
 maven 3.9.6
-ghc 9.8.4

README.md

@@ -1,8 +1,7 @@
 # Field Kit
 
-* a collection of easy-to-use tools that cover common use cases.
+Meant as a collection of easy-to-use tools that cover common use cases.
-* also serves as workspace for exercises.
+WIP.
-    * those results should be migrated to their respective `about-foo` once some knowledge is consolidated.
 
 ## List of Use Cases
 
@@ -21,8 +20,3 @@
 
 * WIN
     * pyenv win
-
-
-### Haskell Kit
-
-asdf plugin add ghc

docker-compose.yaml

@@ -23,19 +23,6 @@ services:
             - ME_CONFIG_MONGODB_ADMINUSERNAME=admin
             - ME_CONFIG_MONGODB_ADMINPASSWORD=password
             - ME_CONFIG_MONGODB_SERVER=mongodb
-
-
-    mariadb:
-        image: mariadb:11.3.2-jammy
-        command: --transaction-isolation=READ-COMMITTED --log-bin=binlog --binlog-format=ROW
-        environment:
-            - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
-            - MYSQL_USER=user
-            - MYSQL_PASSWORD=${MYSQL_PASSWORD}
-            - MYSQL_DATABASE=DB
-        ports:
-            - "24001:3306"
-
 volumes:
     mongo-data:
         driver: local

exercises/sql/company.sql

@@ -1,90 +0,0 @@
--- CREATE
-CREATE TABLE Company
-(
-    company_code VARCHAR(255) PRIMARY KEY,
-    founder      VARCHAR(255)
-);
-
-
-CREATE TABLE Lead_Manager
-(
-    lead_manager_code VARCHAR(255) PRIMARY KEY,
-    company_code      VARCHAR(255)
-);
-
-
-CREATE TABLE Senior_Manager
-(
-    senior_manager_code VARCHAR(255) PRIMARY KEY,
-    lead_manager_code   VARCHAR(255),
-    company_code        VARCHAR(255)
-);
-
-CREATE TABLE Manager
-(
-    manager_code        VARCHAR(255) PRIMARY KEY,
-    senior_manager_code VARCHAR(255),
-    lead_manager_code   VARCHAR(255),
-    company_code        VARCHAR(255)
-);
-
-CREATE TABLE Employee
-(
-    employee_code       VARCHAR(255) PRIMARY KEY,
-    manager_code        VARCHAR(255),
-    senior_manager_code VARCHAR(255),
-    lead_manager_code   VARCHAR(255),
-    company_code        VARCHAR(255)
-);
-
--- INSERT
-
-INSERT INTO Company (company_code, founder)
-VALUES ('C001', 'Alice Johnson'),
-       ('C002', 'Bob Smith');
-
-INSERT INTO Lead_Manager (lead_manager_code, company_code)
-VALUES ('LM001', 'C001'),
-       ('LM002', 'C002');
-
-INSERT INTO Senior_Manager (senior_manager_code, lead_manager_code, company_code)
-VALUES ('SM001', 'LM001', 'C001'),
-       ('SM002', 'LM002', 'C002');
-
-INSERT INTO Manager (manager_code, senior_manager_code, lead_manager_code, company_code)
-VALUES ('M001', 'SM001', 'LM001', 'C001'),
-       ('M002', 'SM002', 'LM002', 'C002');
-
-INSERT INTO Employee (employee_code, manager_code, senior_manager_code, lead_manager_code, company_code)
-VALUES ('E001', 'M001', 'SM001', 'LM001', 'C001'),
-       ('E002', 'M001', 'SM001', 'LM001', 'C001'),
-       ('E003', 'M002', 'SM002', 'LM002', 'C002'),
-       ('E004', 'M002', 'SM002', 'LM002', 'C002');
-
-
--- QUERY
-
-SELECT DISTINCT C.company_code,
-                C.founder,
-                COALESCE(LM.total_lead_managers, 0)   AS total_lead_managers,
-                COALESCE(SM.total_senior_managers, 0) AS total_senior_managers,
-                COALESCE(M.total_managers, 0)         AS total_managers,
-                COALESCE(E.total_employees, 0)        AS total_employees
-FROM Company AS C
-         LEFT JOIN (SELECT DISTINCT company_code,
-                                    COUNT(lead_manager_code) AS total_lead_managers
-                    FROM Lead_Manager
-                    GROUP BY company_code) AS LM ON C.company_code = LM.company_code
-         LEFT JOIN (SELECT DISTINCT company_code,
-                                    COUNT(senior_manager_code) AS total_senior_managers
-                    FROM Senior_Manager
-                    GROUP BY company_code) AS SM ON C.company_code = SM.company_code
-         LEFT JOIN (SELECT DISTINCT company_code,
-                                    COUNT(manager_code) AS total_managers
-                    FROM Manager
-                    GROUP BY company_code) AS M ON C.company_code = M.company_code
-         LEFT JOIN (SELECT DISTINCT company_code,
-                                    COUNT(employee_code) AS total_employees
-                    FROM Employee
-                    GROUP BY company_code) AS E ON C.company_code = E.company_code
-ORDER BY C.company_code;

exercises/sql/diff-counts.sql

@@ -1,48 +0,0 @@
-WITH city_counts AS (SELECT COUNT(CITY)          AS total_cities,
-                            COUNT(DISTINCT CITY) AS distinct_cities
-                     FROM STATION)
-SELECT total_cities - distinct_cities AS city_difference
-FROM city_counts;
--- city_counts is a CTE (Common Table Expression )
--- it is a temp table, which in this case has just one row
-
-
---         Query the list of CITY names from STATION which have vowels (i.e., a, e, i, o, and u) as both their first and last characters.
---             Your result cannot contain duplicates.
-SELECT DISTINCT CITY
-FROM STATION
-WHERE CITY REGEXP '^[aeiouAEIOU].*[aeiouAEIOU]$';
-
-SELECT DISTINCT CITY
-FROM STATION
-WHERE LOWER(SUBSTR(CITY, 1, 1)) IN ('a', 'e', 'i', 'o', 'u')
-  AND LOWER(SUBSTR(CITY, LENGTH(CITY), 1)) IN ('a', 'e', 'i', 'o', 'u');
-
--- NOT start with vowels
-SELECT DISTINCT CITY
-FROM STATION
-WHERE CITY REGEXP '^[^aeiouAEIOU]'; -- ^ae.. negates the expression
-
-
--- NOT end with vowels
-SELECT DISTINCT CITY
-FROM STATION
-WHERE CITY REGEXP '[^aeiouAEIOU]$'; -- ^ae.. negates the expression
-
--- NOT start or END with vowels
-SELECT DISTINCT CITY
-FROM STATION
-WHERE CITY REGEXP '^[^aeiouAEIOU]'
-AND CITY REGEXP '[^aeiouAEIOU]$';
-
-
--- order by last 3 characters, then by ID
-SELECT NAME FROM STUDENTS
-WHERE MARKS > 75
-ORDER BY SUBSTR(NAME, -3), ID;
-
-
-SELECT CITY, LENGTH(CITY) AS NAME_LENGTH
-FROM STATION
-ORDER BY LENGTH(CITY) DESC, CITY ASC
-    LIMIT 1;

exercises/sql/hackers.sql

@@ -1,53 +0,0 @@
--- Create the HACKERS table
-CREATE TABLE HACKERS
-(
-    hacker_id INT PRIMARY KEY,
-    name      VARCHAR(255) NOT NULL
-);
-
--- Create the SUBMISSIONS table
-CREATE TABLE SUBMISSIONS
-(
-    submission_id INT PRIMARY KEY,
-    hacker_id     INT,
-    challenge_id  INT,
-    score         INT,
-    FOREIGN KEY (hacker_id) REFERENCES HACKERS (hacker_id)
-);
-
--- Optional: Insert some sample data into HACKERS
-INSERT INTO HACKERS (hacker_id, name)
-VALUES (1, 'Alice'),
-       (2, 'Bob'),
-       (3, 'Charlie');
-
--- Optional: Insert some sample data into SUBMISSIONS
-INSERT INTO SUBMISSIONS (submission_id, hacker_id, challenge_id, score)
-VALUES (101, 1, 1001, 95),
-       (102, 1, 1002, 90),
-       (103, 2, 1001, 85),
-       (104, 3, 1003, 80);
-
--- Select data to verify the setup
-SELECT *
-FROM HACKERS;
-SELECT *
-FROM SUBMISSIONS;
-
-
-SELECT H.hacker_id,
-       H.name,
-       HTS.total_score
-FROM HACKERS H
-         JOIN
-     (SELECT MaxScores.hacker_id,
-             SUM(MaxScores.max_score) AS total_score
-      FROM (SELECT S.hacker_id,
-                   MAX(S.score) AS max_score
-            FROM SUBMISSIONS S
-            GROUP BY S.hacker_id,
-                     S.challenge_id) AS MaxScores
-      GROUP BY MaxScores.hacker_id
-      HAVING SUM(MaxScores.max_score) > 0) AS HTS ON H.hacker_id = HTS.hacker_id
-ORDER BY HTS.total_score DESC,
-         H.hacker_id;

exercises/sql/population.sql

@@ -1,39 +0,0 @@
--- CREATE
-CREATE TABLE CITY
-(
-    ID          INT PRIMARY KEY,
-    NAME        VARCHAR(255) NOT NULL,
-    COUNTRYCODE VARCHAR(3)   NOT NULL,
-    DISTRICT    VARCHAR(255) NOT NULL,
-    POPULATION  INT          NOT NULL
-);
-
--- INSERT
-INSERT INTO CITY (ID, NAME, COUNTRYCODE, DISTRICT, POPULATION)
-VALUES (1, 'Tokyo', 'JPN', 'Tokyo', 13929286),
-       (2, 'Delhi', 'IN', 'Delhi', 16787941),
-       (3, 'Shanghai', 'CN', 'Shanghai', 24183300),
-       (4, N'São Paulo', 'BR', N'São Paulo', 12106920),
-       (5, 'Mumbai', 'IN', 'Maharashtra', 12442373),
-       (6, 'Cairo', 'EG', 'Cairo', 9500000),
-       (7, 'Dhaka', 'BD', 'Dhaka', 8906039),
-       (8, 'Mexico City', 'MX', 'Mexico City', 9209944),
-       (9, 'Beijing', 'CN', 'Beijing', 21542000),
-       (10, 'Osaka', 'JPN', 'Osaka Prefecture', 8839469);
-
--- QUERY
-
-SELECT ROUND(AVG(POPULATION), 0) AS average_population
-FROM CITY;
-
-SELECT SUM(POPULATION)
-FROM CITY
-WHERE COUNTRYCODE = 'JPN';
-
-
-SELECT MAX(POPULATION) - MIN(POPULATION) AS population_difference
-FROM CITY;
-
-
-
-DROP TABLE CITY;

haskell-kit/hello.hs

@@ -1,4 +0,0 @@
-main =
---    print "Hello World!"
---    putStr "Hello World!"
-    putStrLn "Hello World!"