Re^4: need to parse firts part of SQL-query (regex question)

It's rather like a solution I came up with, albeit without using the module in question:

my $str = 'f1,f2, SUM(f3),CONCAT(f4,f5, f6), f7';

my ( $tok, @toks, $parens );

while ( $str ) {
  my $char = substr $str, 0, 1, '';
  
  $char eq ' ' and next;
  $char eq '(' and $parens++;
  $char eq ')' and $parens--; 
  $char eq ',' && ! $parens
               and push( @toks, $tok ), $tok = '', next;
  
  $tok .= $char;
  push @toks, $tok if ! $str;    
}

print join ' -- ', @toks;
[download]

...but I didn't want to post it for fear that it wouldn't be very robust. :)

Comment on Re^4: need to parse firts part of SQL-query (regex question) Download Code

Replies are listed 'Best First'.
Re^5: need to parse firts part of SQL-query (regex question) by grinder (Bishop) on Jan 17, 2008 at 18:12 UTC
fear that it wouldn't be very robust Yes indeed. Real-world SQL is likely to have named the columns, so you have to deal with `concat(f4, f5, f6) as "foobarquux (combined)"`. Before you know it, you have reimplemented SQL::Tokenizer! • another intruder with the mooring in the heart of the Perl	[reply]