php - 使用 where in 条件和最新时间​​戳连接两个 MySQL 查询

Question

第一个查询是针对选定的机构，第二个查询是为了获取对该机构的最新评论。

第一个查询:

SELECT 
    instituteId, 
    instituteName, 
    description 
FROM institutions 
WHERE instituteId IN ('1','2','3')";

第二个查询:

SELECT 
    name,
    review, 
    timestamp 
FROM reviews 
WHERE instituteId='1' 
ORDER BY timestamp DESC 
LIMIT 1; 

Answer 1

SELECT i.instituteId, 
       i.instituteName, 
       i.description ,
       r.name,
       r.review, 
       r.timestamp
FROM institutions i
INNER JOIN review r
ON i.instituteid = r.instituteId
INNER JOIN (SELECT instituteId,
                   MAX(timestamp) as timestamp
            FROM reviews
            GROUP BY instituteId 
            ) r1
ON r.instituteid = r1.instituteId 
AND r.timestamp = r1.timestamp
WHERE instituteId IN ('1','2','3')