lower_bound

Searches for the object_type with the lowest primary key that is greater than or equal to a given primary key.

Parameters

• primary - Primary key that establishes the target value for the lower bound search.

Returns

An iterator pointing to the object_type that has the lowest primary key that is greater than or equal to primary. If an object could not be found, it will return the end iterator. If the table does not exist** it will return -1.

Example:

C++

#include <eosiolib/eosio.hpp>
using namespace eosio;
using namespace std;
class addressbook: contract {
  struct address {
     uint64_t account_name;
     string first_name;
     string last_name;
     string street;
     string city;
     string state;
     uint32_t zip = 0;
     uint64_t primary_key() const { return account_name; }
     uint64_t by_zip() const { return zip; }
     EOSLIB_SERIALIZE( address, (account_name)(first_name)(last_name)(street)(city)(state)(zip) )
  };
  public:
    addressbook(account_name self):contract(self) {}
    typedef eosio::multi_index< N(address), address, indexed_by< N(zip), const_mem_fun<address, uint64_t, &address::by_zip> > address_index;
    void myaction() {
      address_index addresses(_self, _self);  // code, scope
      // add to table, first argument is account to bill for storage
      addresses.emplace(payer, [&](auto& address) {
        address.account_name = N(dan);
        address.first_name = "Daniel";
        address.last_name = "Larimer";
        address.street = "1 EOS Way";
        address.city = "Blacksburg";
        address.state = "VA";
        address.zip = 93446;
      });
      addresses.emplace(payer, [&](auto& address) {
        address.account_name = N(brendan);
        address.first_name = "Brendan";
        address.last_name = "Blumer";
        address.street = "1 EOS Way";
        address.city = "Hong Kong";
        address.state = "HK";
        address.zip = 93445;
      });
      uint32_t zipnumb = 93445;
      auto zip_index = addresses.get_index<N(zip)>();
      auto itr = zip_index.lower_bound(zipnumb);
      eosio_assert(itr->account_name == N(brendan), "Incorrect First Lower Bound Record ");
      itr++;
      eosio_assert(itr->account_name == N(dan), "Incorrect Second Lower Bound Record");
      itr++;
      eosio_assert(itr == zip_index.end(), "Incorrect End of Iterator");
    }
}
EOSIO_ABI( addressbook, (myaction) )