我有三个表,并期望得到如下结果,但我不知道如何更正我的sql语句。stay, isnull(guest.nights,0) as nightsleftjoin(select company,count(*) as stay,sum(nights) as nights from guest group by company) guest on guest.company=history.company
leftjoin (selec
select event_slots.id as event_slot_id, u.first_name, u.id AS user_id,
sum(case when next_round = 2 then 1 else 0 end) AS no
leftjoin users as u on u.id = event_slots.selected_by_u
我有一个有几千行的表:从这个表中,我需要为列band中的每个值提取列WTE的总数,包括总数为0的那些值。我还需要每个合计都在它自己的列中,这样我就可以轻松地更新汇总表。我目前拥有的代码返回相关行的值: IF(band="E",WTE,0) AS `Band6_WTE`LEFTJOIN `instances` AS iWHERE i.region
name)
我想要得到所有大学,所有学生和单个学生每个月的费用(如果学生在某所大学没有花费任何东西:select year(sm.date) as year, s.id_student, s.name, u.university_name as university_name
from ((schema.students s <em
下面是我的ActiveRecord代码:.select("computers.id, SUM(services.cost) asSCOST, SUM(repairs.cost) as RCOST")此操作运行良好,并返回以下正确的SQL:
`SELECT computers.id, SUM(services.cost) as S