I'm in a bit of a pickle, I have to perform a query on a database with rather poor data quality. I am trying to evaluate a field which contains a date, but which was defined as a nvarchar. I thought I would be able to cast the value to an integer but this fails as there also non-date values in the date field (random letters and signs,etc...).

What I decided to do is as follows:

SELECT q.foo, cast( q.bar as int) 
FROM ( SELECT foo,bar FROM table where ISNUMERIC(bar) = 1) as q 
WHERE q.bar > 20140401

But this still crashes stating conversion failed on the nvarchar value '. '. I expected that all values would be castable to int as they were numeric?