DDevelopment & Design

Sorting strings in Oracle by national rules

  • byModulo
  • February 18, 2011
  • 1 minute read

Sometimes we need to sort a list by rules of a national letter order, e.g. in Polish the national charactes are mostly place between original the Latin ones: … b, c, ć, d, e, ę, f … In other languages, it can be even more sophisticated, like in Spanish, where ll is located after lz, so a single character replacement wouldn’t work.

If we sort the following way:

SELECT * FROM TABLE (SYS.ODCIVARCHAR2LIST(‘cde’, ‘ća’, ‘dx’, ‘ca’)) ORDER BY COLUMN_VALUE;

We’ll get: ca, cde, dx, ća and that’s wrong. To sort the list correctly, we can specify a language rule: NLSSORT(COLUMN_VALUE,’NLS_LANG=pl’):

SELECT * FROM TABLE (SYS.ODCIVARCHAR2LIST(‘cde’, ‘ća’, ‘dx’, ‘ca’)) RDER BY NLSSORT(COLUMN_VALUE,’NLS_LANG=pl’);

Finally we’ll get the correct result: ca, cde, ća, dx.

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Grails render as JSON catch

One of a reasons your controller doesn't render a proper response in JSON format might be wrong package name that you use. It is easy to overlook. Import are on top of a file, you look at your code and everything seems to be fine. Except response is still not in JSON format.

Consider this simple controller:

class RestJsonCatchController {
def grailsJson() {
render([first: 'foo', second: 5] as grails.converters.JSON)
    }

def netSfJson() {
render([first: 'foo', second: 5] as net.sf.json.JSON)
    }
}

And now, with finger crossed... We have a winner!

$ curl localhost:8080/example/restJsonCatch/grailsJson
{"first":"foo","second":5}
$ curl localhost:8080/example/restJsonCatch/netSfJson
{first=foo, second=5}

As you can see only grails.converters.JSON converts your response to JSON format. There is no such converter for net.sf.json.JSON, so Grails has no converter to apply and it renders Map normally.

Conclusion: always carefully look at your imports if you're working with JSON in Grails!

Edit: Burt suggested that this is a bug. I've submitted JIRA issue here: GRAILS-9622 render as class that is not a codec should throw exception