Ejercicio 1: Calcula la tasa de infección

SELECT RefugeID,
Population,
Infected,InfectionRate FROM
(SELECT
RefugeID,
Population,
Infected,
Round(CAST((Infected * 100.0 / Population) AS DECIMAL(5,2)),2) AS InfectionRate
FROM
SurvivorStats) As IR
WHERE
InfectionRate > 5
ORDER BY
InfectionRate DESC;

Ejercicio 2: Clasifica refugios según estado crítico

SELECT
RefugeID,
FoodRations,
WaterLiters,
CASE
WHEN FoodRations < 10 OR WaterLiters < 50 THEN 'CRITICAL'
ELSE 'OK'
END AS Status
FROM RefugeSupplies
ORDER BY Status,RefugeID;

Ejercicio 3: Cuenta refugios por estado

SELECT RS.Status, COUNT(*) AS RefugeCount
FROM
(SELECT
CASE
WHEN FoodRations < 10 OR WaterLiters = DATEADD(DAY, -7, GETDATE())) AS MS
GROUP BY SightingDate
ORDER BY SightingDate;

Ejercicio 5: Mutantes cerca de refugios críticos

SELECT
rs.RefugeID,
ms.SightingDate,
ms.Latitude,
ms.Longitude
FROM RefugeSupplies rs
INNER JOIN MutantSightings ms
ON ABS(rs.Latitude – ms.Latitude) <= 0.5
AND ABS(rs.Longitude – ms.Longitude) <= 0.5
WHERE (rs.FoodRations < 10 OR rs.WaterLiters = DATEADD(DAY, -3, (SELECT MAX(SightingDate) AS MaxDate
FROM MutantSightings))
ORDER BY RefugeID, SightingDate;