Re: [Boost-users] [Boost][multi_index] proper way to make a complex query

I will definetly try what you have suggested and get back to you, thank you for your quick reply! JOAQUIN LOPEZ MU?Z wrote:

[...]

Hello Sebastien,

I'm not sure I've fully understood all the details of your problem, but seems to me that composite keys ( http://tinyurl.com/hdf3q ) might be of help here. A composite key accepts several attributes and presents the records sorted in lexicographical order with respect to them. In your particular case, suppose you've got an index (non-unique) whose key is

composite_key< meteo_record, const_mem_fun, const_mem_fun, const_mem_fun, const_mem_fun, const_mem_fun

(where I've used some imaginary names for the attribute getters). This index sorts records lexicographically by

grid_type,var_name,ip2,ip1Kind,ip1

which looks like what you're after, from what I understand about the description of your current query process. The different groups can be then traversed like follows (for simplicity I assume the composite key is used in index #0, you'll probably want to have it in an additional index):

for(recordIter=set.begin();recordIter!=set.end();) { recordIter2=set.upper_range( boost::make_tuple( it->get_grid_type(), it->get_var_name(), it->get_ip2(), it->get_ipKind(), ) );

// [recorditer1,recorditer2) is a range of elements with equal // grid_type,var_name,ip2 and ipKind, sorted by ip1 process(recordIter1,recordIter2);

recordIter1=recordIter2; }

Is this what you were looking for? Thank you for using Boost.MultiIndex,

Joaquín M López Muñoz Telefónica, Investigación y Desarrollo _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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