CREATE TABLE properties (property_id VARCHAR2)
CREATE TABLE residents (property_id VARCHAR2)

How many residents does each property have? List property id and resident count.
SELECT T1.property_id, COUNT(*) FROM properties AS T1 JOIN residents AS T2 ON T1.property_id = T2.property_id GROUP BY T1.property_id
SELECT "T1"."property_id", COUNT(*) FROM "properties" "T1" JOIN "residents" "T2" ON "T1"."property_id" = "T2"."property_id" GROUP BY "T1"."property_id"