when
‘ChangeProductName‘=
case --联名借姓名
--when a.ChangeProductName is not null then (substring(a.ChangeProductName,0,charindex(‘,‘, ChangeProductName))) --联名借姓名
--when a.ChangeProductName <> ‘‘ then (substring(a.ChangeProductName,0,charindex(‘,‘, ChangeProductName)))
when (a.ChangeProductName is not null and a.ChangeProductName <> ‘‘) then substring(a.ChangeProductName,0,charindex(‘,‘, ChangeProductName)) --联名借姓名
end,
sql case when 多条件
原文：http://www.cnblogs.com/dullbaby/p/5485428.html
