Tạo mảng JSON lồng nhau bằng FOR JSON PATH

Bạn có thể sử dụng truy vấn sau:

SELECT pr.person_id AS [person.id], pr.person_name AS [person.name],
    (
        SELECT pt.pet_id AS id, pt.pet_name AS name 
        FROM @Pets pt WHERE pt.pet_owner=pr.person_id 
        FOR JSON PATH
    ) AS [person.pet]
FROM @Persons pr 
FOR JSON PATH, ROOT('pet owners')

Để biết thêm thông tin, hãy xem https://blogs.msdn.microsoft.com/sqlserverstorageengine/2015/10/09/returning-child-rows-formatted-as-json-in-sql-server-queries/