Here is my scenario, I'm creating a dynamic query using a select statement which uses functions to generate the query. I am storing it into a variable and running it using exec. i.e.

declare @dsql nvarchar(max)
set @dsql = ''

select @dsql = @dsql + dbo.getDynmicQuery(column1, column2)
from Table1

exec(@dsql)

Now it produces the many errors in this scenario, like 'Incorrect syntax near ','' and 'Case expressions may only be nested to level 10.'

But if i take the text from @dsql and assign it a variable manually like:

declare @dsql nvarchar(max)
set @dsql = ''

set @dsql = N'<Dynamic query text>'
exec(@dsql)

it runs and generates the result, what could be the reason for that ??

Thanks..