sql 查询ids

id	value1	value2	value3
1	1	1	1
2	32	2	1
4	1	3	1

这时要 查出结果为 1，2，4 sql语句

select GROUP_CONCAT(id) as ids from databases limit 0,1

结果为string 1,2,4

SELECT group_concat(id separator ';') as a FROM `cmf_portal_category` WHERE  (  parent_id = 37 ) limit 0,1

//tp5写法：
$cate_drivers_infos = Db::name('portal_category')->field("group_concat(id separator ';') as ids")->where('parent_id = 37')->find()['ids'];

//结果集
结果为string  1;2;4;5