参考一,这是若有重复,显示最小id的那一条,"SELECT * FROM ".DB::table('favorites')." WHERE id IN (SELECT min(id) FROM ".DB::table('favorites')." GROUP BY svip) ORDER BY ……";
显示 ID 最大的那个,刚试用了你的代码, $favorites_query = DB::query("SELECT * FROM ".DB::table('favorites')." WHERE id IN (SELECT min(id) FROM ".DB::table('favorites')." GROUP BY svip) ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");出现错误提示: [Type] 查询语句安全威胁 [Query] SELECT * FROM favorites WHERE id IN (SELECT min(id) FROM favorites GROUP BY svip) ORDER BY svupdatetime DESC LIMIT 0, 20
$favorites_query = DB::query("SELECT DISTINCT(svip) FROM ".DB::table('favorites')." ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");
$favorites_query = DB::query("SELECT DISTINCT(svip),uid,svname FROM ".DB::table('favorites')." ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");需要的字段再后面追加即可
奇怪,应该显示数据的地方直接显示空白了。使用下面代码能正常显示,但是怎样让它显示重复数据中最新的一条呢?$favorites_query = DB::query("SELECT * FROM ".DB::table('favorites')." GROUP BY svip ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");
看到一个例子,但有点不理解:SELECT emp2.dept_id, emp1.name, emp1.gender, emp2.max_salary FROM ( SELECT dept_id, Max(salary) as max_salary FROM employees GROUP BY dept_id ) as emp2 JOIN employees as emp1 ON emp1.salary = emp2.max_salary GROUP BY dept_id;
显示 ID 最大的那个,刚试用了你的代码, $favorites_query = DB::query("SELECT * FROM ".DB::table('favorites')." WHERE id IN (SELECT min(id) FROM ".DB::table('favorites')." GROUP BY svip) ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");出现错误提示:
[Type] 查询语句安全威胁
[Query] SELECT * FROM favorites WHERE id IN (SELECT min(id) FROM favorites GROUP BY svip) ORDER BY svupdatetime DESC LIMIT 0, 20
奇怪,应该显示数据的地方直接显示空白了。使用下面代码能正常显示,但是怎样让它显示重复数据中最新的一条呢?$favorites_query = DB::query("SELECT * FROM ".DB::table('favorites')." GROUP BY svip ORDER BY svupdatetime DESC LIMIT $start_limit, $perpage");
emp1.name,
emp1.gender,
emp2.max_salary
FROM (
SELECT dept_id,
Max(salary) as max_salary
FROM employees
GROUP BY dept_id
) as emp2 JOIN employees as emp1 ON emp1.salary = emp2.max_salary
GROUP BY dept_id;