[ Renier Leenders]

"SELECT FROM law WHERE article_number >= x and article_number <= y". Unfortunately not all law articles are numbered with 1, 2, 3, etc. If they were I could define article_number as integer. But some articles are numbered with 1, 2, 2a ... 13ab etc. When I define the article_number as char and I retrieve I get a result with an sorting order like this: 1,10,11,11a,11b,12, 13ab ... 2a, 20, 21,21a. I could not find a database who supports "natural sort". Has someone an idea to work around this problem with Zope? Any suggestions would be appreciated.

This can be difficult, especially if the depth of the subdivisions can be unbounded. Sometimes it is possible to use a computed column as the sort index. This is easiest when there are just numbers, no letters. If the numbers have no subdivisions, as you seem to be showing, and ther can only be a single letter after the number, I would probably try to sort using computed columns like this (using imaginary functions - look up to see what string handling functions your database supports): Select substring(article_number, 1, len(article_number)-1) as main_index, right(article_number,1) as secondary_index, article_title Order by main_index, secondary_index For a more complicated numbering system, you may still be able to do something similar using database functions. Otherwise you would have to compute the sort order with Python. With numbers like 1, 1.1, 1.1.1, 1.1.2, I like to multiply each division be a corresponding power of ten and add them up to get a single sort index. 1.2.3 would become 1*10^2 + 2*10^1 + 3 = 123 , for example. Note that this is not exactly like just removing the separaators because the trailing number might be missing (e.g., 1.2).Again, whether you can do this depends on the database. Some people like to precompute the sort order and store it in the database. I try to avoid this, but once in a while it can be useful. Cheers, Tom P