我尝试了以下 MySQL 更新，但它只设置了第一个字段c.avg_price_dil而不是第二个字段c.avg_dilution。
奇怪的是，当我将更新分成如下所示的两部分时，两者都可以同时更新两个字段。是否存在影响此调用的基于组的函数？
更新了两个字段- 仅c.avg_price_dil更新。
update corp_act as c
inner join (
select
m.gvkey, m.gvkey_iid, m.date_base, avg(m.price_dil) as avg_price,
avg(m.dilution) as avg_dilution
from master as m
inner join corp_act as c
on c.gvkey = m.gvkey AND
m.date_base between c.date_base AND
LAST_DAY(c.date_base + INTERVAL 11 MONTH)
where c.actioncd not in ('N/C','REA','SPN') AND
c.actioncd IS NOT NULL
group by m.gvkey_iid, c.actioncd) as x
on
x.gvkey = c.gvkey AND
x.date_base = c.date_base
set
c.avg_price_dil = if(x.avg_price is null, 0, x.avg_price) AND
c.avg_dilution = if(x.avg_dilution is null, 0, x.avg_dilution)
当分成两个更新时，两者都有效：
稀释更新： - 工作正常
update corp_act as c
inner join (
select
m.gvkey, m.gvkey_iid, m.date_base, avg(m.dilution) as avg_dilution
from master as m
inner join corp_act as c
on c.gvkey = m.gvkey AND
m.date_base between c.date_base AND
LAST_DAY(c.date_base + INTERVAL 11 MONTH)
where c.actioncd not in ('N/C','REA','SPN') AND
c.actioncd IS NOT NULL
group by m.gvkey_iid, c.actioncd) as x
on
x.gvkey = c.gvkey AND
x.date_base = c.date_base
set
c.avg_dilution = if(x.avg_dilution is null, 0, x.avg_dilution)
价格更新： - 工作正常
update corp_act as c
inner join (
select
m.gvkey, m.gvkey_iid, m.date_base, avg(m.price_dil) as avg_price
from master as m
inner join corp_act as c
on c.gvkey = m.gvkey AND
m.date_base between c.date_base AND
LAST_DAY(c.date_base + INTERVAL 11 MONTH)
where c.actioncd not in ('N/C','REA','SPN') AND
c.actioncd IS NOT NULL
group by m.gvkey_iid, c.actioncd) as x
on
x.gvkey = c.gvkey AND
x.date_base = c.date_base
set
c.avg_price_dil = if(x.avg_price is null, 0, x.avg_price)
这两者之间的唯一区别是我只avg在单个函数中使用该函数一次。
有任何想法吗？谢谢你的帮助。