我想检查数据，但如果它为空或空忽略它。目前查询如下…
Select
Coalesce(listing.OfferText, company.OfferText, '') As Offer_Text,
from tbl_directorylisting listing
Inner Join tbl_companymaster company
On listing.company_id= company.company_id
但我想找个伴。OfferText如果列表。Offertext是一个空字符串，如果它是null。
最好的解决方案是什么?
当前回答
要检查变量是否为空，请使用以下命令:
IF LEN(ISNULL(@var, '')) = 0
-- Is empty or NULL
ELSE
-- Is not empty and is not NULL
其他回答
SELECT
COALESCE(listing.OfferText, 'company.OfferText') AS Offer_Text,
FROM
tbl_directorylisting listing
INNER JOIN tbl_companymaster company ON listing.company_id= company.company_id
[Column_name] > ' '不包含空字符串和空字符串。在单引号之间有一个空格。
这里有一个解决方案，但我不知道它是否是最好的....
Select
Coalesce(Case When Len(listing.Offer_Text) = 0 Then Null Else listing.Offer_Text End, company.Offer_Text, '') As Offer_Text,
from tbl_directorylisting listing
Inner Join tbl_companymaster company
On listing.company_id= company.company_id
您可以使用ISNULL并根据已知输出检查答案:
SELECT case when ISNULL(col1, '') = '' then '' else col1 END AS COL1 FROM TEST
[Column_name] IS NULL OR LEN(RTRIM(LTRIM([Column_name]))) = 0
