Update README.md

README.md

@@ -1,2 +1,68 @@
 # prawo-jazdy-resources
 
+`db/main.py` is an *extremely* badly-written script that reads files published by the Ministry of Infrastructure and imports them into a database; reads data from `pytania.csv` and `punkty.csv`
+- `db/pytania.csv` is the `katalog_pytania_egzminacyjne_kandydat__14112024.xlsx` file from [here](https://www.gov.pl/web/infrastruktura/prawo-jazdy), opened in Libreoffice Calc and saved as csv
+- `db/punkty.csv` isn't published by the Ministry, so you have to send a freedom of information request to acquire it; it is processed the same way as `pytania.csv`
+
+The database structure is as follows: 
+```sql
+CREATE TABLE tasks (
+    id integer NOT NULL,
+    correct_answer boolean,
+    media_url text,
+    weight smallint
+);
+
+CREATE TABLE questions (
+    task_id integer,
+    lang character(2),
+    text text
+);
+
+CREATE TABLE tasks_advanced (
+    id integer NOT NULL,
+    correct_answer character(1),
+    media_url text,
+    weight smallint
+);
+
+CREATE TABLE questions_advanced (
+    task_id integer,
+    lang character(2),
+    text text,
+    answer_a text,
+    answer_b text,
+    answer_c text
+);
+
+CREATE TABLE categories (
+    name text,
+    task_id integer
+);
+```
+
+The basic tasks can be queried like so:
+```sql
+SELECT tasks.correct_answer, tasks.media_url, tasks.weight, questions.text
+FROM tasks
+    LEFT JOIN questions ON tasks.id = questions.task_id
+    LEFT JOIN categories ON tasks.id = categories.task_id
+WHERE
+    categories.name = 'B' AND
+    questions.lang = 'PL'
+ORDER BY random()
+LIMIT (20);
+```
+And the advanced tasks like this:
+```sql
+SELECT tasks_advanced.correct_answer, tasks_advanced.media_url, tasks_advanced.weight,
+       questions_advanced.text, questions_advanced.answer_a, questions_advanced.answer_b, questions_advanced.answer_c
+FROM tasks_advanced
+    LEFT JOIN questions_advanced ON tasks_advanced.id = questions_advanced.task_id
+    LEFT JOIN categories ON tasks_advanced.id = categories.task_id
+WHERE
+    categories.name = 'B' AND
+    questions_advanced.lang = 'PL'
+ORDER BY random()
+LIMIT (20);
+```