Databases
StackOverflow2013
Postsdbo
POAssociative array with multiple keys types, possible?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POAssociative array with multiple keys types, possible?
    primarykey
    data
    text
    <p>Ive got a large bunch of objects (potentially 1000's) which I need to store in a container. I need to be able to find specific instances in two ways, either by its ID number (64bit unsigned int), or its name (std::string). Generally by ID will be the most common, however in some cases the name is known, but not the ID.</p> <p>std::map can provide a single &lt;-> value, however I'm not sure if having 2 sets of std::map containers, one for the Ids and another for the strings is the best approach here.</p> <p>EDIT - REVISED code and error:</p> <p>Ok, I figured i'd give the multi index a try since I have boost anyways, however I can't seem to get it to compile even though I've done it exactly the same as in the documentation as far as I can tell :(</p> <p>test code:</p> <pre><code>namespace common { class MyBaseClass { public: typedef boost::uint64_t Id; //name and id are constant, at least for the period im intrested in //when I want it in the container... const std::string &amp;getName()const{return name;} Id getId()const{return id;} ...other stuff... }; } class MyClass : public common::MyBaseClass { ...other stuff... }; typedef boost::multi_index_container &lt; MyClass*, boost::indexed_by &lt; boost::ordered_unique&lt;boost::const_mem_fun&lt;MyBaseClass, MyBaseClass::Id, &amp;MyBaseClass::getId &gt; &gt;, boost::ordered_unique&lt;boost::const_mem_fun&lt;MyBaseClass, const std::string&amp;, &amp;MyBaseClass::getName&gt; &gt; &gt; &gt;MyClassList; </code></pre> <p>and your average boost template error...</p> <blockquote> <p>c:\lib\c++\boost\boost\aligned_storage.hpp(69) : error C2872: 'detail' : ambiguous symbol<br> could be 'boost::detail'<br> or 'boost::multi_index::detail'<br> c:\lib\c++\boost\boost\multi_index\detail\index_node_base.hpp(42) : see reference to class template instantiation 'boost::aligned_storage' being compiled<br> with<br> [<br> size_=4,<br> alignment_=4<br> ]<br> c:\lib\c++\boost\boost\multi_index\detail\index_node_base.hpp(47) : see reference to class template instantiation 'boost::multi_index::detail::pod_value_holder' being compiled<br> with<br> [<br> Value=MyClass *<br> ]<br> c:\lib\c++\boost\boost\multi_index\detail\ord_index_node.hpp(582) : see reference to class template instantiation 'boost::multi_index::detail::index_node_base' being compiled<br> with<br> [<br> Value=MyClass *,<br> Allocator=std::allocator<br> ]<br> c:\lib\c++\boost\boost\multi_index\ordered_index.hpp(137) : see reference to class template instantiation 'boost::multi_index::detail::ordered_index_node' being compiled<br> with<br> [<br> Super=boost::multi_index::detail::index_node_base><br> ]<br> c:\lib\c++\boost\boost\multi_index\ordered_index.hpp(119) : see reference to class template instantiation 'boost::multi_index::detail::ordered_index' being compiled<br> with<br> [<br> KeyFromValue=boost::multi_index::const_mem_fun,<br> Compare=std::less,std::allocator>>,<br> SuperMeta=boost::multi_index::detail::nth_layer&lt;2,MyClass *,boost::multi_index::indexed_by>,boost::multi_index::ordered_unique>>,std::allocator>,<br> TagList=boost::mpl::vector0,<br> Category=boost::multi_index::detail::ordered_unique_tag<br> ]<br> c:\lib\c++\boost\boost\multi_index_container.hpp(86) : see reference to class template instantiation 'boost::multi_index::detail::ordered_index' being compiled<br> with<br> [<br> KeyFromValue=boost::multi_index::const_mem_fun,<br> Compare=std::less,<br> SuperMeta=boost::multi_index::detail::nth_layer&lt;1,MyClass *,boost::multi_index::indexed_by>,boost::multi_index::ordered_unique>>,std::allocator>,<br> TagList=boost::mpl::vector0,<br> Category=boost::multi_index::detail::ordered_unique_tag<br> ]<br> c:\projects\bad_angle_studios\brak3\trunk\source\source\server\MyClass.cpp(18) : see reference to class template instantiation 'boost::multi_index::multi_index_container' being compiled<br> with<br> [<br> Value=MyClass *,<br> IndexSpecifierList=boost::multi_index::indexed_by>,boost::multi_index::ordered_unique>><br> ]<br> c:\lib\c++\boost\boost\aligned_storage.hpp(53) : error C2872: 'detail' : ambiguous symbol<br> could be 'boost::detail'<br> or 'boost::multi_index::detail'<br> c:\lib\c++\boost\boost\aligned_storage.hpp(56) : see reference to class template instantiation 'boost::detail::aligned_storage::aligned_storage_imp::data_t' being compiled<br> with<br> [<br> size_=4,<br> alignment_=4<br> ]<br> c:\lib\c++\boost\boost\aligned_storage.hpp(69) : see reference to class template instantiation 'boost::detail::aligned_storage::aligned_storage_imp' being compiled<br> with<br> [<br> size_=4,<br> alignment_=4<br> ]<br> c:\lib\c++\boost\boost\aligned_storage.hpp(73) : error C2872: 'detail' : ambiguous symbol<br> could be 'boost::detail'<br> or 'boost::multi_index::detail'<br> c:\projects\bad_angle_studios\brak3\trunk\source\source\server\MyClass.cpp(44) : error C2676: binary '[' : 'MyClassList' does not define this operator or a conversion to a type acceptable to the predefined operator</p> </blockquote>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USFire Lancer
    1. USFire Lancer
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POAssociative array with multiple keys types, possible?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POAssociative array with multiple keys types, possible?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI am sorry i have no dev environment on my laptop here. Does it compile if you use common::MyBaseClass instead of MyClass when typedef'ing MyClassList ?
      singulars
      1. POAssociative array with multiple keys types, possible?
      1. USBenoît
    2. COok, I changed it to the base class and made it use "cosnt std::string&", however now I get a different error...
      singulars
      1. POAssociative array with multiple keys types, possible?
      1. USFire Lancer
    3. COok I edited the main post to reflect he changes and new error
      singulars
      1. POAssociative array with multiple keys types, possible?
      1. USFire Lancer
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload