Perl's text handling to the rescue....

There was a very interesting proble set forward at the Ingres forum, quoting :

"I have to use an Ingres Database to store my data which is in several languages (like french, german, and so on). In my web site, the user can use the function "search".
The problem are the special characters like éàèâ in french, or öäü in german. The user doesn't enter these characters, but it should be found anyway.

For example:
 

In the database is the word "château". The user types "chateau" (whithout â)
The program should find the "château", even if "chateau" was typed.

So all accents in the database should be replaced by something more
useful (like "_") 

Has someone an idea how to do that?

Ingres database version : 9.2.1 
 

Thanks a lot, Kakmael"

 and this is my attempt to tackle it,using Perl,of course


Ok you so you get the latin1 encoded string "Chateu" from your web form and you pass it to a CGI Perl script which does the following :

use charnames ':full';
use strict;
my $input_string="Chateau";
my @results;
my %mappings=( "\N{LATIN SMALL LETTER A}" => ["\N{LATIN SMALL LETTER A WITH GRAVE}","\N{LATIN SMALL LETTER A WITH DIAERESIS}"]);

@results=("'".$input_string."'");

foreach my $hash_key (keys %mappings) {
    foreach my $array_key ( @{$mappings{$hash_key}} ) {
        my $temp;
        ($temp=$input_string)=~ s/$hash_key/$array_key/;
        push @results, "'".$temp."'";
    }
}

my $search_string;
 {
local $"=",";
$search_string= 'SELECT * FROM test WHERE col2 in ' . '(' . "@results" . ')' ;
}

print $search_string;

basically you have a hash that maps the to be replaced characters to their counterparts by storing them into an anonymous array reference :

my %mappings=( "\N{LATIN SMALL LETTER A}" => ["\N{LATIN SMALL LETTER A WITH GRAVE}","\N{LATIN SMALL LETTER A WITH DIAERESIS}"]);

then you iterate through the nested data structure and you substitute the sought after character with its counterpart (the two foreach loops) and then you build the final string with a neat trick to get the right amount of commas correct
So the final $search_string will contain ('Chateu','Chàteu','Chäteu')

Of course this does not cover all possible cases (for example do you want all the 'a' replaced or just the first one??) since after all I don't know what the exact requirements are, and will need some tweaking, but you get the drift