表:patients
+-------------+---------+ | Column Name | Type | +-------------+---------+ | patient_id | int | | patient_name| varchar | | age | int | +-------------+---------+ patient_id 是这张表的唯一主键。 每一行表示一个患者的信息。
表:covid_tests
+-------------+---------+ | Column Name | Type | +-------------+---------+ | test_id | int | | patient_id | int | | test_date | date | | result | varchar | +-------------+---------+ test_id 是这张表的唯一主键。 每一行代表一个 COVID 检测结果。结果可以是阳性、阴性或不确定。
编写一个解决方案以找到从 COVID 中康复的患者——那些曾经检测呈阳性但后来检测呈阴性的患者。
返回结果表以 recovery_time
升序 排序,然后以 patient_name
升序 排序。
结果格式如下所示。
示例:
输入:
patients 表:
+------------+--------------+-----+ | patient_id | patient_name | age | +------------+--------------+-----+ | 1 | Alice Smith | 28 | | 2 | Bob Johnson | 35 | | 3 | Carol Davis | 42 | | 4 | David Wilson | 31 | | 5 | Emma Brown | 29 | +------------+--------------+-----+
covid_tests 表:
+---------+------------+------------+--------------+ | test_id | patient_id | test_date | result | +---------+------------+------------+--------------+ | 1 | 1 | 2023-01-15 | Positive | | 2 | 1 | 2023-01-25 | Negative | | 3 | 2 | 2023-02-01 | Positive | | 4 | 2 | 2023-02-05 | Inconclusive | | 5 | 2 | 2023-02-12 | Negative | | 6 | 3 | 2023-01-20 | Negative | | 7 | 3 | 2023-02-10 | Positive | | 8 | 3 | 2023-02-20 | Negative | | 9 | 4 | 2023-01-10 | Positive | | 10 | 4 | 2023-01-18 | Positive | | 11 | 5 | 2023-02-15 | Negative | | 12 | 5 | 2023-02-20 | Negative | +---------+------------+------------+--------------+
输出:
+------------+--------------+-----+---------------+ | patient_id | patient_name | age | recovery_time | +------------+--------------+-----+---------------+ | 1 | Alice Smith | 28 | 10 | | 3 | Carol Davis | 42 | 10 | | 2 | Bob Johnson | 35 | 11 | +------------+--------------+-----+---------------+
解释:
输出表以 recovery_time 升序排序,然后以 patient_name 升序排序。