簡(jiǎn)單的sql語(yǔ)句,由于自己水平一般,不知道錯(cuò)在哪里...忘熟悉語(yǔ)句的人指導(dǎo)一二,謝謝!select new_name as 年度,count(new_name) as 總份數(shù),round(sum(case new_q01 when '0' then filterednew_survey.new_q01when filterednew_survey.new_q01 is null then '0'else(filterednew_survey.new_q01-1.00)end),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分from filterednew_surveygroup by new_name為什么這句提示關(guān)鍵字 'is' 附近有語(yǔ)法錯(cuò)誤???selectnew_name as year,count(new_name) as quantity,round(sum(isnull(new_q01,1.00)-1.00)/sum(casewhen new_q01 is null then 0else 1 end ),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分from filterednew_surveygroup by new_name這句沒(méi)有問(wèn)題.selectnew_name as year,count(new_name) as quantity,round(sum(isnull(new_q01,1.00)-1.00)/sum(casewhen new_q01 is null then 0else 1 end ),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分from filterednew_surveygroup by new_name這句也沒(méi)有問(wèn)題請(qǐng)各位指導(dǎo)下~~~經(jīng)過(guò)幾位的幫忙,我自己修改了一下,改成select new_name as 年度,count(new_name) as 總份數(shù),round(sum(case new_q01 when '0' then filterednew_survey.new_q01else (isnull(filterednew_survey.new_q01,1.00)-1.00)end),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分from filterednew_surveygroup by new_name也重新理解了下isnull但是有還是有點(diǎn)小小的不明白selectnew_name as year,count(new_name) as quantity,round(sum(isnull(new_q01,1.00)-1.00)/sum(casewhen new_q01 is null then 0else 1 end ),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分from filterednew_surveygroup by new_name為什么這句的也是is null then 0就可以呢?
2 回答
慕少森
TA貢獻(xiàn)2019條經(jīng)驗(yàn) 獲得超9個(gè)贊
select new_name as 年度,
count(new_name) as 總份數(shù),
round(sum(case isnull(new_q01,0) when '0' then '0'
else(filterednew_survey.new_q01-1.00) end),2) as 產(chǎn)品的銷(xiāo)售價(jià)格打分
from filterednew_survey
group by new_name
改成這個(gè)試一下
-------------------------------
when new_q01 is null then 0
else 1 end
這個(gè)是不行的 你會(huì)發(fā)現(xiàn) 不管他是不是null 他返回的都是1
拉風(fēng)的咖菲貓
TA貢獻(xiàn)1995條經(jīng)驗(yàn) 獲得超2個(gè)贊
ISNULL使用指定的替換值替換 NULL。
語(yǔ)法
ISNULL ( check_expression , replacement_value )
IS NULL 是兩個(gè)關(guān)鍵字，在一起用是判斷指定的內(nèi)容是否是 null
兩個(gè)似乎沒(méi)有什么可比性
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