Implement SQL assessment queries

calculate_largest_expensors.sql

@@ -0,0 +1,20 @@
+SELECT
+    e.employee_id,
+    e.first_name || ' ' || e.last_name AS employee_name,
+    e.manager_id,
+    m.first_name || ' ' || m.last_name AS manager_name,
+    SUM(x.unit_price * x.quantity) AS total_expensed_amount
+FROM employee e
+JOIN expense x
+    ON e.employee_id = x.employee_id
+LEFT JOIN employee m
+    ON e.manager_id = m.employee_id
+GROUP BY
+    e.employee_id,
+    e.first_name,
+    e.last_name,
+    e.manager_id,
+    m.first_name,
+    m.last_name
+HAVING SUM(x.unit_price * x.quantity) > DECIMAL '1000.00'
+ORDER BY total_expensed_amount DESC;

create_employees.sql

@@ -0,0 +1,26 @@
+CREATE TABLE employee (
+    employee_id TINYINT,
+    first_name VARCHAR,
+    last_name VARCHAR,
+    job_title VARCHAR,
+    manager_id TINYINT
+);
+
+INSERT INTO employee (
+    employee_id,
+    first_name,
+    last_name,
+    job_title,
+    manager_id
+)
+VALUES
+    (1, 'Ian', 'James', 'CEO', 4),
+    (2, 'Umberto', 'Torrielli', 'CSO', 1),
+    (3, 'Alex', 'Jacobson', 'MD EMEA', 2),
+    (4, 'Darren', 'Poynton', 'CFO', 2),
+    (5, 'Tim', 'Beard', 'MD APAC', 2),
+    (6, 'Gemma', 'Dodd', 'COS', 1),
+    (7, 'Lisa', 'Platten', 'CHR', 6),
+    (8, 'Stefano', 'Camisaca', 'GM Activation', 2),
+    (9, 'Andrea', 'Ghibaudi', 'MD NAM', 2);
+

create_expenses.sql

@@ -0,0 +1,20 @@
+CREATE TABLE expense (
+    employee_id TINYINT,
+    unit_price DECIMAL(8, 2),
+    quantity TINYINT
+);
+
+INSERT INTO expense (
+    employee_id,
+    unit_price,
+    quantity
+)
+VALUES
+    (3, DECIMAL '6.50', 14),
+    (3, DECIMAL '11.00', 20),
+    (3, DECIMAL '22.00', 18),
+    (3, DECIMAL '13.00', 75),
+    (9, DECIMAL '300.00', 1),
+    (4, DECIMAL '40.00', 9),
+    (2, DECIMAL '17.50', 4);
+

create_invoices.sql

@@ -0,0 +1,35 @@
+CREATE TABLE supplier (
+    supplier_id TINYINT,
+    name VARCHAR
+);
+
+CREATE TABLE invoice (
+    supplier_id TINYINT,
+    invoice_ammount DECIMAL(8, 2),
+    due_date DATE
+);
+
+INSERT INTO supplier (
+    supplier_id,
+    name
+)
+VALUES
+    (1, 'Catering Plus'),
+    (2, 'Dave''s Discos'),
+    (3, 'Entertainment tonight'),
+    (4, 'Ice Ice Baby'),
+    (5, 'Party Animals');
+
+INSERT INTO invoice (
+    supplier_id,
+    invoice_ammount,
+    due_date
+)
+VALUES
+    (5, DECIMAL '6000.00', DATE '2026-09-30'),
+    (1, DECIMAL '2000.00', DATE '2026-08-31'),
+    (1, DECIMAL '1500.00', DATE '2026-09-30'),
+    (2, DECIMAL '500.00', DATE '2026-07-31'),
+    (3, DECIMAL '6000.00', DATE '2026-09-30'),
+    (4, DECIMAL '4000.00', DATE '2026-12-31');
+

find_manager_cycles.sql

@@ -0,0 +1,35 @@
+WITH RECURSIVE manager_paths (
+    start_employee_id,
+    current_employee_id,
+    path,
+    cycle_found
+) AS (
+    SELECT
+        employee_id AS start_employee_id,
+        manager_id AS current_employee_id,
+        ARRAY[employee_id, manager_id] AS path,
+        employee_id = manager_id AS cycle_found
+    FROM employee
+
+    UNION ALL
+
+    SELECT
+        mp.start_employee_id,
+        e.manager_id AS current_employee_id,
+        concat(mp.path, ARRAY[e.manager_id]) AS path,
+        contains(mp.path, e.manager_id) AS cycle_found
+    FROM manager_paths mp
+    JOIN employee e
+        ON mp.current_employee_id = e.employee_id
+    WHERE mp.cycle_found = false
+)
+SELECT DISTINCT
+    element_at(path, cardinality(path)) AS employee_id,
+    slice(
+        path,
+        array_position(path, element_at(path, cardinality(path))),
+        cardinality(path) - array_position(path, element_at(path, cardinality(path))) + 1
+    ) AS loop
+FROM manager_paths
+WHERE cycle_found = true
+ORDER BY employee_id;

generate_supplier_payment_plans.sql

@@ -0,0 +1,69 @@
+WITH invoice_payment_months AS (
+    SELECT
+        invoice.supplier_id,
+        supplier.name AS supplier_name,
+        invoice.invoice_ammount,
+        invoice.due_date,
+        date_diff('month', DATE '2026-06-30', invoice.due_date) AS payment_month_count
+    FROM invoice
+    JOIN supplier
+        ON invoice.supplier_id = supplier.supplier_id
+),
+invoice_monthly_payments AS (
+    SELECT
+        supplier_id,
+        supplier_name,
+        invoice_ammount / payment_month_count AS payment_amount,
+        last_day_of_month(date_add('month', month_offset, DATE '2026-06-01')) AS payment_date
+    FROM invoice_payment_months
+    CROSS JOIN UNNEST(sequence(0, payment_month_count - 1)) AS months(month_offset)
+),
+supplier_monthly_payments AS (
+    SELECT
+        supplier_id,
+        supplier_name,
+        payment_date,
+        SUM(payment_amount) AS payment_amount
+    FROM invoice_monthly_payments
+    GROUP BY
+        supplier_id,
+        supplier_name,
+        payment_date
+),
+supplier_totals AS (
+    SELECT
+        supplier_id,
+        SUM(invoice_ammount) AS total_invoice_amount
+    FROM invoice
+    GROUP BY supplier_id
+),
+payment_plan AS (
+    SELECT
+        supplier_monthly_payments.supplier_id,
+        supplier_monthly_payments.supplier_name,
+        supplier_monthly_payments.payment_date,
+        supplier_monthly_payments.payment_amount,
+        supplier_totals.total_invoice_amount
+    FROM supplier_monthly_payments
+    JOIN supplier_totals
+        ON supplier_monthly_payments.supplier_id = supplier_totals.supplier_id
+)
+SELECT
+    supplier_id,
+    supplier_name,
+    CAST(payment_amount AS DECIMAL(8, 2)) AS payment_amount,
+    CAST(
+        total_invoice_amount
+        - SUM(payment_amount) OVER (
+            PARTITION BY supplier_id
+            ORDER BY payment_date
+            ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+        )
+        AS DECIMAL(8, 2)
+    ) AS balance_outstanding,
+    payment_date
+FROM payment_plan
+ORDER BY
+    supplier_id,
+    payment_date;
+