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我试过以下MySQL更新,但它只设置第一个字段c.avg_price_dil
而不是第二个字段c.avg_dilution
。为什么MySQL只更新1字段而不是2?
奇怪的部分是,当我将更新分成两部分,如下所示,两个字段都更新。是否存在影响此调用的基于组的函数?
已更新两个字段 - 仅更新了c.avg_price_dil
。
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,无论工作:
稀释更新时间: - 正常工作
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: - 正常工作
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)
唯一的d这两者之间的区别在于,我仅在个别函数中使用了一次函数avg
。
任何想法? 感谢您的帮助。
哇,我是个白痴。为此非常感谢。 –