Solution Lab | SQL Basics Week 11 Day 1

files_for_lab/solutions.sql

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+-- Lab | SQL basics (selection and aggregation)
+
+-- Query 1
+-- Get the `id` values of the first 5 clients from `district_id` with a value equals to 1.
+SELECT client_id FROM client WHERE district_id = 1 ORDER BY client_id ASC LIMIT 5;
+
+-- Query 2
+-- In the `client` table, get an `id` value of the last client where the `district_id` equals to 72.
+SELECT client_id FROM client WHERE district_id = 72 ORDER BY client_id DESC LIMIT 1;
+
+-- Query 3
+-- Get the 3 lowest amounts in the `loan` table.
+SELECT amount FROM loan ORDER BY amount ASC LIMIT 3;
+
+-- Query 4
+-- What are the possible values for `status`, ordered alphabetically in ascending order in the `loan` table?
+SELECT DISTINCT(status) FROM loan ORDER BY status;
+
+-- Query 5
+-- What is the `loan_id` of the highest payment received in the `loan` table?
+SELECT loan_id FROM loan ORDER BY payments DESC LIMIT 1;
+
+-- Query 6
+-- What is the loan `amount` of the lowest 5 `account_id`s in the `loan` table? Show the `account_id` and the corresponding `amount`
+SELECT account_id, amount FROM loan ORDER BY account_id ASC LIMIT 5;
+
+-- Query 7
+-- What are the `account_id`s with the lowest loan `amount` that have a loan `duration` of 60 in the `loan` table?
+-- From the expected output the limit is missing (5)
+SELECT account_id FROM loan WHERE duration = 60 ORDER BY amount ASC LIMIT 5;
+
+-- Query 8
+-- What are the unique values of `k_symbol` in the `order` table?
+-- Skipping blank values (with space char)
+SELECT DISTINCT(k_symbol) FROM `order` WHERE k_symbol != ' ' ORDER by k_symbol;
+
+-- Query 9
+-- In the `order` table, what are the `order_id`s of the client with the `account_id` 34?
+SELECT order_id FROM `order` WHERE account_id = 34;
+
+-- Query 10
+-- In the `order` table, which `account_id`s were responsible for orders between `order_id` 29540 and `order_id` 29560 (inclusive)?
+SELECT DISTINCT(account_id) FROM `order` where order_id BETWEEN 29540 AND 29560;
+
+-- Query 11
+-- In the `order` table, what are the individual amounts that were sent to (`account_to`) id 30067122?
+SELECT DISTINCT(amount) FROM `order` WHERE account_to = 30067122;
+
+-- Query 12
+-- In the `trans` table, show the `trans_id`, `date`, `type` and `amount` of the 10 first transactions from `account_id` 793 in chronological order, from newest to oldest.
+SELECT trans_id, date, type, amount FROM trans WHERE account_id = 793 ORDER BY date DESC LIMIT 10;
+
+-- Query 13
+-- In the `client` table, of all districts with a `district_id` lower than 10, how many clients are from each `district_id`? Show the results sorted by the `district_id` in ascending order.
+SELECT COUNT(client_id) FROM client WHERE district_id < 10 GROUP BY district_id ORDER BY district_id;
+
+-- Query 14
+-- In the `card` table, how many cards exist for each `type`? Rank the result starting with the most frequent `type`.
+SELECT type, COUNT(*) AS total FROM card GROUP BY type ORDER BY total DESC;
+
+-- Query 15
+-- Using the `loan` table, print the top 10 `account_id`s based on the sum of all of their loan amounts.
+SELECT account_id, SUM(amount) as total_amount FROM loan GROUP BY account_id ORDER BY total_amount DESC LIMIT 10;
+
+-- Query 16
+-- In the `loan` table, retrieve the number of loans issued for each day, before (excl) 930907, ordered by date in descending order.
+SELECT date, count(*) FROM loan WHERE date < 930907 GROUP BY date ORDER BY date DESC;
+
+-- Query 17
+-- In the `loan` table, for each day in December 1997, count the number of loans issued for each unique loan duration, ordered by date and duration, both in ascending order. You can ignore days without any loans in your output.
+SELECT date, duration, COUNT(*) FROM loan WHERE date BETWEEN 971201 and 971231 GROUP BY date, duration ORDER BY date, duration ASC;
+
+-- Query 18
+-- In the `trans` table, for `account_id` 396, sum the amount of transactions for each type (`VYDAJ` = Outgoing, `PRIJEM` = Incoming). Your output should have the `account_id`, the `type` and the sum of amount, named as `total_amount`. Sort alphabetically by type.
+SELECT account_id, type, SUM(amount) from trans WHERE account_id = 396 GROUP BY type;