LAB | SQL basics

solutions.sql

@@ -0,0 +1,156 @@
+----------------------- 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  
+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 
+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_ids in the loan table? Show the account_id and the corresponding amount
+
+SELECT account_id , amount 
+FROM loan
+ORDER BY account_id   
+LIMIT 5
+
+-- Query 7
+-- What are the account_ids with the lowest loan amount that have a loan duration of 60 in the loan table?
+
+SELECT account_id 
+FROM loan
+WHERE duration == 60
+ORDER BY amount    
+LIMIT 5
+
+
+-- Query 8
+-- What are the unique values of k_symbol in the order table?
+-- Note: There shouldn't be a table name order, since order is reserved from the ORDER BY clause. 
+-- You have to use backticks to escape the order table name.
+
+SELECT DISTINCT (k_symbol) 
+FROM 'order'
+
+-- Query 9
+-- In the order table, what are the order_ids 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_ids 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 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(district_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(card_id)
+FROM card
+GROUP BY type
+ORDER BY COUNT(card_id) DESC
+
+-- Query 15
+-- Using the loan table, print the top 10 account_ids based on the sum of all of their loan amounts.
+
+SELECT account_id, SUM(amount)
+FROM loan
+GROUP BY account_id
+ORDER BY SUM(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(loan_id)
+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(loan_id)
+FROM loan
+WHERE date BETWEEN 971201 AND 971231  -- from 97 12 01  to  97 12 31
+GROUP BY date, duration
+ORDER BY date, duration
+
+-- 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) AS total_amount
+FROM trans
+WHERE account_id == 396
+GROUP BY type
+ORDER BY type
+
+