Finished wasb sql test commit

calculate_largest_expensors.sql

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+USE memory.default;
+
+WITH EmployeeExpenses AS (
+    SELECT
+        employee_id,
+        SUM(unit_price * quantity) AS total_expensed_amount
+    FROM
+        memory.default.EXPENSE
+    GROUP BY
+        employee_id
+    HAVING
+        SUM(unit_price * quantity) > 1000
+)
+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,
+    ee.total_expensed_amount
+FROM
+    memory.default.EMPLOYEE e
+    JOIN EmployeeExpenses ee ON e.employee_id = ee.employee_id
+    LEFT JOIN memory.default.EMPLOYEE m ON e.manager_id = m.employee_id
+ORDER BY
+    ee.total_expensed_amount DESC;

create_employees.sql

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+USE memory.default;
+
+-- DROP TABLE memory.default.EMPLOYEE;
+
+CREATE TABLE memory.default.EMPLOYEE (
+    employee_id TINYINT,
+    first_name VARCHAR,
+    last_name VARCHAR,
+    job_title VARCHAR,
+    manager_id TINYINT
+);
+
+INSERT INTO memory.default.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

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+USE memory.default;
+
+-- DROP TABLE memory.default.EXPENSE;
+
+CREATE TABLE memory.default.EXPENSE (
+    employee_id TINYINT,
+    unit_price DECIMAL(8,2),
+    quantity TINYINT
+);
+
+INSERT INTO memory.default.EXPENSE VALUES
+(3,6.50,14),
+(3,11.0,22),
+(3,22.0,18),
+(3,13.00,75),
+(9,300.00,1),
+(4,40.00,9),
+(2,17.50,4);
+

create_invoices.sql

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+USE memory.default;
+
+-- DROP TABLE memory.default.INVOICE;
+
+CREATE TABLE memory.default.INVOICE (
+    supplier_id TINYINT,
+    invoice_amount DECIMAL(8,2),
+    due_date DATE
+);
+
+-- DROP TABLE memory.default.SUPPLIER;
+
+
+CREATE TABLE memory.default.SUPPLIER (
+    supplier_id TINYINT,
+    name VARCHAR
+);
+
+INSERT INTO memory.default.SUPPLIER (supplier_id, name) VALUES
+(1, 'Catering Plus'),
+(2, 'Dave''s Discos'),
+(3, 'Entertainment tonight'),
+(4, 'Ice Ice Baby'),
+(5, 'Party Animals');
+
+INSERT INTO memory.default.INVOICE (supplier_id, invoice_amount, due_date) VALUES
+(1, 2000.00, DATE '2025-01-31'),
+(1, 1500.00, DATE '2025-02-28'),
+(2, 500.00, DATE '2024-12-31'),
+(3, 6000.00, DATE '2025-02-28'),
+(4, 4000.00, DATE '2025-04-30'),
+(5, 6000.00, DATE '2025-02-28');

find_manager_cycles.sql

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+USE memory.default;
+
+WITH RECURSIVE Hierarchy (employee_id, manager_id, path) AS (
+    SELECT
+        employee_id,
+        manager_id,
+        ARRAY[CAST(employee_id AS VARCHAR)] AS path
+    FROM
+        memory.default.EMPLOYEE
+
+    UNION ALL
+
+
+    SELECT
+        h.employee_id,
+        m.manager_id,
+        h.path || CAST(m.employee_id AS VARCHAR)
+    FROM
+        Hierarchy h
+        JOIN memory.default.EMPLOYEE m ON h.manager_id = m.employee_id
+    WHERE
+        NOT contains(h.path, CAST(m.employee_id AS VARCHAR))
+)
+SELECT
+    employee_id,
+    array_join(path, ' -> ') AS cycle
+FROM
+    Hierarchy
+WHERE
+    contains(path, CAST(manager_id AS VARCHAR));

generate_supplier_payment_plans.sql

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+USE memory.default;
+
+-- STEPS I TOOK - thought process:
+--       1. Count the number of 'payments' (instalments) for each supplier.
+--       2. Divide all invoices into payments
+--       3. Aggregate payments per supplier for each month
+--       4. Set payment_date (last day of each consecutive month until payment month)
+--       5. Join with SUPPLIER table to get supplier names.
+--       6. Optimise code using CTE to improve readability and reusability
+
+-- Get data about invoices
+WITH invoice_data AS (
+    SELECT
+        supplier_id,
+        invoice_amount,
+        due_date,
+        date_diff('month', current_date, due_date) AS months_until_due,
+        current_date
+    FROM memory.default.INVOICE
+), -- Generate payment schedule
+     payment_schedule AS (
+         SELECT
+             supplier_id,
+             invoice_amount / months_until_due AS monthly_payment,
+             last_day_of_month(date_add('month', month_index - 1, current_date)) AS payment_date
+         FROM invoice_data
+                  CROSS JOIN UNNEST(sequence(1, months_until_due)) AS t(month_index)
+     ), -- Aggregate monthly payments for each supplier
+     monthly_totals AS (
+         SELECT
+             supplier_id,
+             payment_date,
+             SUM(monthly_payment) AS total_monthly_payment,
+             SUM(SUM(monthly_payment)) OVER (PARTITION BY supplier_id) AS total_amount
+         FROM payment_schedule
+         GROUP BY supplier_id, payment_date
+     )
+
+-- Generate balance_outstanding (left to pay after each payment) and join table SUPPLIERS to get supplier names
+SELECT
+    monthly_totals.supplier_id,
+    suppliers.name AS supplier_name,
+    monthly_totals.total_monthly_payment AS payment_amount,
+    GREATEST(monthly_totals.total_amount - SUM(monthly_totals.total_monthly_payment) OVER (
+        PARTITION BY monthly_totals.supplier_id
+        ORDER BY monthly_totals.payment_date
+        ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+    ), 0) AS balance_outstanding,
+    monthly_totals.payment_date
+FROM monthly_totals
+         JOIN memory.default.SUPPLIER AS suppliers ON monthly_totals.supplier_id = suppliers.supplier_id
+ORDER BY monthly_totals.supplier_id, monthly_totals.payment_date;