-- Aggregate-only starter queries. Do not select VIN, plate, email, session,
-- upload-log, or raw JSON fields into a public-facing application.
BEGIN TRANSACTION READ ONLY;

SELECT
    count(*) AS registration_records,
    min(registration_date) AS earliest_registration,
    max(registration_date) AS latest_registration
FROM data.dmv_tax;

SELECT
    extract(year FROM registration_date)::integer AS registration_year,
    count(*) AS records
FROM data.dmv_tax
GROUP BY 1
ORDER BY 1;

SELECT
    upper(trim(county)) AS county,
    count(*) AS records
FROM data.dmv_tax
GROUP BY 1
ORDER BY 2 DESC;

SELECT
    upper(replace(trim(fuel_type), '-', ' ')) AS canonical_fuel_type,
    count(*) AS records
FROM data.dmv_tax_vehicle
GROUP BY 1
ORDER BY 2 DESC;

SELECT
    count(*) AS inspection_records,
    min(test_start) AS earliest_test,
    max(test_start) AS latest_test
FROM data.inspection_search;

SELECT
    extract(year FROM test_start)::integer AS test_year,
    count(*) AS records
FROM data.inspection_search
GROUP BY 1
ORDER BY 1;

SELECT
    lower(trim(county)) AS county_source,
    coalesce(nullif(upper(trim(overall_result)), ''), '<BLANK/NULL>') AS result,
    count(*) AS records
FROM data.inspection_search
GROUP BY 1, 2
ORDER BY 1, 3 DESC;

ROLLBACK;