Month: February 2012
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SQL Having
The having clause is used when filtering has to be performed on aggregate functions since the where clause can not be used in this situation. Since the having clause is often used in conjunction with the group by clause the examples on this page use the same data as was used in the group by article…
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SQL Group By
The group by statement is generally used in conjunction with the various aggregate functions in order to produce results that are grouped by one or more columns. This is a very powerful way to report results for groups of results that share some common trait – in the example below the shared trait we are…
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MikroTik RB751G Configuration
This page describes the initial set up of my MikroTik RB751G router with a Thompson Gateway TG585v7 BeBox. Although that sounds quite specific these settings are should work with most or all ADSL routers that are in bridge mode and other RouterBoard devices.
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Setting a value to null with EL
Beginning with Expression Language (EL) 2.2 it is possible to call method with arguments. I feel that most of the time it is generally a good idea to try not to use this feature because it breaks the KISS principal but when you need it it can be a life saver.
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Dynamic DataTable with JSF 2.0
A project I’m working on recently presented me with the problem of totally dynamically creating a data table on a JSF page. At first sight I assumed this would be fairly trivial since I had created a number of other components dynamically with no problems. The difference though was that the other components (for example…
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JSF Object Not Found
I recently decided to try writing my own JSF component as I had a need that wasn’t met by the excellent PrimeFaces component library. I had read some horror stories about how hard it is to write custom components so I’d put off doing it as I didn’t want to get bogged down when I had so…