WHERE some_col > ''
Since null > '' produces unknown, this has the effect of filtering out both null and empty strings.
@JoshPinter: coalesce(some_col, '') = ''
REQUEST: Only when the request comes directly from the client
FORWARD: Only when the request has been forwarded to a component (see Transferring Control to Another Web Component)
INCLUDE: Only when the request is being processed by a component that has been included (see Including Other Resources in the Response)
ERROR: Only when the request is being processed with the error page mechanism (see Handling Servlet Errors)
You can direct the filter to be applied to any combination of the preceding situations by selecting multiple dispatcher types. If no types are specified, the default option is REQUEST.
Der rechtlich einwandfreie Umgang mit Spam erhitzt die Gemüter: Es gilt nicht nur, den täglich wachsenden Schaden durch unerwünschte E-Mail-Massen zu begrenzen, sondern auch durch geeignete Gestaltung der Gegenmaßnahmen keinen Straftatbestand zu erfüllen – ein Spagat.
The order the container uses in building the chain of filters to be applied for a particular request URI is as follows:
First, the <url-pattern> matching filter mappings in the same order that these elements appear in the deployment descriptor.
Next, the <servlet-name> matching filter mappings in the same order that these elements appear in the deployment descriptor.
A. Snoeren. SIGCOMM '01: Proceedings of the 2001 conference on Applications,
technologies, architectures, and protocols for computer communications, page 3--14. New York, NY, USA, ACM, (2001)
S. Czerwinski, B. Zhao, T. Hodes, A. Joseph, and R. Katz. MobiCom '99: Proceedings of the 5th annual ACM/IEEE international
conference on Mobile computing and networking, page 24--35. New York, NY, USA, ACM, (1999)
Y. Lim, and B. Farhang-Boroujeny. IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 39 (5):
316-318(May 1992)description of fast filter bank construction.
S. Nicolas, B. Moulin, and G. Mineau. Proceedings of the 11th International Conference on Conceptual Structures (ICCS 2003), volume 2746 of Lecture Notes in Computer Science, page 362-377. Springer, (2003)