feat: succesfully complete all challenges

src/answers.sql

@@ -1,15 +1,278 @@
 -- Your answers here:
 -- 1
+SELECT
+    type,
+    SUM(mount) AS total_money
+FROM
+    accounts
+GROUP BY
+    type
+ORDER BY
+    type ASC;
 
 -- 2
+WITH eligible_users AS (
+    SELECT
+        user_id
+    FROM
+        accounts
+    WHERE
+        type = 'CURRENT_ACCOUNT'
+    GROUP BY
+        user_id
+    HAVING
+        COUNT(*) >= 2
+)
+SELECT
+    COUNT(*) AS total_users
+FROM
+    eligible_users;
+
 
 -- 3
+SELECT
+    TYPE,
+    account_id,
+    mount
+FROM
+    accounts
+ORDER BY
+    mount DESC
+LIMIT
+    5;
 
 -- 4
 
+SELECT 
+    usr.id AS user_uuid, 
+    SUM(CASE 
+            WHEN mov.type = 'IN' THEN mov.mount 
+            WHEN mov.type IN ('OUT', 'TRANSFER', 'OTHER') THEN -mov.mount 
+            ELSE 0 
+        END) + SUM(act.mount) AS final_balance
+FROM users usr
+INNER JOIN accounts act 
+    ON usr.id = act.user_id
+INNER JOIN movements mov
+    ON mov.account_from = act.id
+GROUP BY usr.id
+ORDER BY final_balance DESC
+LIMIT 3;
+
+
+
+
 -- 5
 
+--(A) First, get the ammount for the account 3b79e403-c788-495a-a8ca-86ad7643afaf and fd244313-36e5-4a17-a27c-f8265bc46590 after all their movements. 
+SELECT 
+    a.id AS account_id,
+    a.mount+
+	(SUM(
+        CASE 
+            WHEN m.account_from = a.id THEN -m.mount 
+            WHEN m.account_to = a.id THEN m.mount  
+        END
+    )) AS final_account_amount,
+FROM 
+    accounts a
+INNER JOIN 
+    movements m
+ON 
+    a.id IN (m.account_from, m.account_to)
+WHERE 
+    a.id IN ('3b79e403-c788-495a-a8ca-86ad7643afaf', 'fd244313-36e5-4a17-a27c-f8265bc46590')
+GROUP BY 
+    a.id, a.mount;
+
+
+
+
+--(B) Add a new movement with the information: from: 3b79e403-c788-495a-a8ca-86ad7643afaf make a transfer to fd244313-36e5-4a17-a27c-f8265bc46590 mount: 50.75
+DO $$ 
+DECLARE
+    issuing_account UUID := '3b79e403-c788-495a-a8ca-86ad7643afaf';
+    receiving_account UUID := 'fd244313-36e5-4a17-a27c-f8265bc46590';
+    transfer_amount NUMERIC := 50.75;
+BEGIN
+
+    UPDATE accounts
+    SET mount = mount - transfer_amount
+    WHERE id = first_account;
+
+    UPDATE accounts
+    SET mount = mount + transfer_amount
+    WHERE id = second_account;
+
+    INSERT INTO movements (id, type, account_from, account_to, mount, created_at, updated_at)
+    VALUES (
+        gen_random_uuid(),  
+        'TRANSFER',         
+        issuing_account,      
+        receiving_account,     
+        transfer_amount,    
+        NOW(),              
+        NOW()               
+    );
+
+    RAISE NOTICE 'Transaction completed from % to % with the amount of %', 
+                issuing_account, receiving_account, transfer_amount;
+END $$;
+
+
+
+
+-----------------------------------------
+--Shows the result of the tranfer--
+-----------------------------------------
+SELECT 
+    m.type, 
+    m.account_from, 
+    m.account_to, 
+    m.mount AS transferred_amount
+FROM movements m
+WHERE m.account_from = '3b79e403-c788-495a-a8ca-86ad7643afaf'
+    OR m.account_to = '3b79e403-c788-495a-a8ca-86ad7643afaf'
+ORDER BY m.created_at ASC;
+
+
+
+--(c) Add a new movement with the information: from: 3b79e403-c788-495a-a8ca-86ad7643afaf type: OUT mount: 731823.56
+DO $$ 
+DECLARE
+    current_balance NUMERIC;
+	affected_account UUID:= '3b79e403-c788-495a-a8ca-86ad7643afaf';
+	out_amount NUMERIC := 731823.56;
+BEGIN
+
+    SELECT a.mount INTO current_balance
+    FROM accounts a
+    WHERE a.id = affected_account;
+
+    IF current_balance < out_amount THEN
+        RAISE EXCEPTION 'Insufficient balance to do the movement, Transaction rejected';
+    END IF;
+
+    INSERT INTO movements (id, type, account_from, account_to, mount, created_at, updated_at)
+    VALUES (
+        gen_random_uuid(),
+        'OUT', 
+        affected_account,
+		NULL,
+		-- out_amount, --5.e you need to pass less money or
+        now(),
+        now()
+    );
+
+EXCEPTION
+WHEN OTHERS THEN
+    RAISE NOTICE '*** Error processing the transaction %. current balance: % % ** Doing ROLLBACK **', 
+                out_amount, current_balance, CHR(10);
+    ROLLBACK;
+    RETURN;
+
+
+--( f). f. Once the transaction is correct, make a commit
+END $$; --> the same as commit
+
+
+
+--(g) How much money the account fd244313-36e5-4a17-a27c-f8265bc46590 have:
+
+CREATE FUNCTION get_user_balance(account_id UUID)
+RETURNS DOUBLE PRECISION AS $$
+DECLARE
+    final_balance DOUBLE PRECISION;
+BEGIN
+    SELECT 
+        SUM(CASE 
+                WHEN mov.type = 'IN' THEN mov.mount 
+                WHEN mov.type IN ('OUT', 'TRANSFER', 'OTHER') THEN -mov.mount 
+                ELSE 0 
+            END) + SUM(act.mount)
+    INTO final_balance
+    FROM users usr
+    INNER JOIN accounts act 
+        ON usr.id = act.user_id
+    INNER JOIN movements mov
+        ON mov.account_from = act.id
+    WHERE usr.id = user_id
+    GROUP BY usr.id;
+    RETURN final_balance;
+END;
+$$ LANGUAGE plpgsql;
+
+
+SELECT get_user_balance('fd244313-36e5-4a17-a27c-f8265bc46590') AS net_balance; --<==== directly the net balance of the account
+
+
 -- 6
 
+SELECT 
+    u.id AS user_id,
+    u.name AS user_name,
+    u.email AS user_email,
+    a.id AS account_id,
+    m.id AS movement_id,
+    m.type AS movement_type,
+    m.account_from AS account_from,
+    m.account_to AS account_to
+FROM 
+    users u
+INNER JOIN 
+    accounts a
+ON 
+    u.id = a.user_id
+INNER JOIN 
+    movements m
+ON 
+    a.id IN (m.account_from, m.account_to)
+WHERE 
+    a.id = '3b79e403-c788-495a-a8ca-86ad7643afaf'
+ORDER BY 
+    m.created_at ASC;
+
 -- 7
 
+SELECT 
+    u.name AS user,
+    u.email AS email,
+    SUM(a.mount) AS total_money
+FROM 
+    users u
+INNER JOIN 
+    accounts a
+ON 
+    u.id = a.user_id
+GROUP BY 
+    u.id, u.name, u.email
+ORDER BY 
+    total_money DESC
+LIMIT 1;
+
+--8
+SELECT 
+    u.name AS user_name,
+    a.id AS account_id,
+    a.type AS account_type,
+    m.id AS UUID_movement,
+    m.type AS movement_type,
+    m.account_from AS account_from,
+    m.account_to AS account_to,
+    m.created_at AS movement_date
+FROM 
+    users u
+INNER JOIN 
+    accounts a
+ON 
+    u.id = a.user_id
+LEFT JOIN 
+    movements m
+ON 
+    a.id IN (m.account_from, m.account_to)
+WHERE 
+    u.email = '[email protected]'
+ORDER BY 
+    a.type ASC,
+    m.created_at ASC;
+

src/partitionBy.sql

@@ -0,0 +1,35 @@
+SELECT 
+    u.id AS user_id,
+    u.name AS user_name,
+    u.email AS user_email,
+    a.id AS account_id,
+    a.mount AS initial_money,
+    m.id AS movement_id,
+    m.type AS movement_type,
+    m.account_from AS account_from,
+    m.account_to AS account_to,
+    m.mount AS movement_amount,
+    a.mount + 
+    SUM(
+        CASE 
+            WHEN m.account_from = a.id THEN -m.mount
+            WHEN m.account_to = a.id THEN m.mount
+        END
+    ) OVER (
+        PARTITION BY a.id 
+        ORDER BY m.created_at
+    ) AS total_money
+FROM 
+    users u
+INNER JOIN 
+    accounts a
+ON 
+    u.id = a.user_id
+LEFT JOIN 
+    movements m
+ON 
+    a.id IN (m.account_from, m.account_to)
+WHERE 
+    a.id = '3b79e403-c788-495a-a8ca-86ad7643afaf'
+ORDER BY 
+    m.created_at ASC;