group by where条件的设置

/*
where要放在group by前面
group by 后面加条件只能用having关键字
*/

select case_id, count(*) from  td
    inner join TD_PROC proc
    on td.wf_proc_id = proc.businessid
    and proc.type != ’done’
where case_id is not null --where要放在group by前面
group by case_id

--可用having case_id is not null