sql server - SQL to retrieve first sentence from a block of text -

i have following sql sql server:

declare @summary1 nvarchar(max) declare @summary2 nvarchar(max)  set @summary1='this long text. rest of text' set @summary2='some text no full stops'  select substring(@summary1, 1,charindex('.', @summary1)) sentence select substring(@summary2, 1,charindex('.', @summary2)) sentence 

i want able first sentence "summary" , if there no full stop return text. example @summary1 works fine no full stop in text nothing returned.

anyone have bright ideas how can achieve this?

i use caseexpression:

select  case charindex('.', @summary1)  -- determine if sentence contains full stop     when 0 @summary1       -- if not return whole sentence     else substring(@summary1, 1, charindex('.', @summary1))  -- else first part end sentence