获取 mysql 中最近记录的组的所有 ID
Getting all id's of group with recent record in mysql
我的 MySQL 数据库中有不同组代码的用户。我正在根据他们当前的位置将他们的经纬度保存在数据库中。
Problem is I am not able to get their recent records according to their group code.
我试过了
SELECT * FROM tracklatlong WHERE id IN (SELECT MAX( id ) FROM
tracklatlong GROUP BY 'track_CfiUw');
但我只得到这个 track_CfiUw 组代码的最后一条记录。
我想要如下结果
您的查询应该是这样的,
SELECT tl1.id,tl1.admin_id,tl1.name,tl1.groupcode
FROM tracklatlong tl1
LEFT JOIN tracklatlong tl2 ON (tl1.name = tl2.name AND tl1.id < tl2.id)
WHERE tl2.id IS NULL AND tl1.groupcode = 'track_CfiUw';
但您却按 group_code value
对它进行分组。
我的 MySQL 数据库中有不同组代码的用户。我正在根据他们当前的位置将他们的经纬度保存在数据库中。
Problem is I am not able to get their recent records according to their group code.
我试过了
SELECT * FROM tracklatlong WHERE id IN (SELECT MAX( id ) FROM
tracklatlong GROUP BY 'track_CfiUw');
但我只得到这个 track_CfiUw 组代码的最后一条记录。
我想要如下结果
您的查询应该是这样的,
SELECT tl1.id,tl1.admin_id,tl1.name,tl1.groupcode
FROM tracklatlong tl1
LEFT JOIN tracklatlong tl2 ON (tl1.name = tl2.name AND tl1.id < tl2.id)
WHERE tl2.id IS NULL AND tl1.groupcode = 'track_CfiUw';
但您却按 group_code value
对它进行分组。