multiple definitions of symbol linker error using sql_create_#

[Graham Reitz]

I created a header file where I placed all of my sql_create_# macros.

I keep getting multiple definition linker errors.

/usr/bin/ld: multiple definitions of symbol agencies::names
(there are more, but similar)

What am I missing?

The code looks as follows:

// start file my_tables.h
#include <mysql++.h>
#include <custom.h>
#include <string>

#ifndef _TABLES_HPP_
#define _TABLES_HPP_

sql_create_3(agencies, 1, 3,
               unsigned int,          agency_id,
               std::string,           agency_name,
               std::string,           agency_contact)

sql_create_3(billing, 1, 3,
               unsigned int,         billing_id,
               std::string,          billing_agency_name,
               std::string,          billing_first_name)
#endif // _TABLES_HPP_
// end file my_tables.h

// start file my_db.h
#ifndef _MY_DB_H_
#define _MY_DB_H_

#include <string>
#include <vector>

#include <boost/noncopyable.hpp>
#include "my_tables.h"

class my_db : boost::noncopyable
{
public:
     explicit my_db(std::string tcp_ip_address, unsigned int  
port_number,
                     std::string db_name, std::string db_username,
                     std::string db_password);
};
#endif // _MY_DB_H_
// end file my_db.h

// start file my_db.cpp
#include <mysql++.h>
#include "tac_db.h"

my_db::my_db(std::string tcp_ip_address, unsigned int port_number,
                std::string db_name, std::string db_username,
                std::string db_password)
{
     // Connect to the database
     mysqlpp::Connection connection(db_name.c_str(),  
tcp_ip_address.c_str(),
         db_username.c_str(), db_password.c_str(), port_number, false);
}
// end file my_db.cpp