如何用SQL语句查询后，返回不存在的值，并用一个0代替
如何用SQL语句查询后，返回不存在的值，并用0代替
select isNull(PremiumOld,0) as PremiumOld from view_Prodect
where Material='304HC' and [Name]='GB818' and Specification='M1.6*18'
如果这个语句查询没有结果。则显示 列名 PremiumOld 显示为 0
[解决办法]
select isNull(PremiumOld,0) as PremiumOld from view_Prodect
where Material='304HC' and [Name]='GB818' and Specification='M1.6*18'
union all
select 0 as PremiumOld from (select 0 as A) as TB where not exists(select 1 from view_Prodect
where Material='304HC' and [Name]='GB818' and Specification='M1.6*18')
[解决办法]
select case when isNull(PremiumOld,'')='' then 0 Else PremiumOld End as PremiumOld from view_Prodect
where Material='304HC' and [Name]='GB818' and Specification='M1.6*18'
