Sociはテーブル内のすべてのデータを行単位で出力します

Question

スキーマを知らなければ、どのようにすればいいですか？これは私がこれまで持っているものです。

row r; 
soci::statement st = (mSql->prepare << 
       "select * from tab", 
       soci::into(r)); 

st.execute(); 
while (st.fetch()) 
{ 
     //want a way to print each row 
} 

Answer 1

私はこのようにそれをやった、それが列で出力します：

soci::row v; 
    soci::statement st = (mSql->prepare << "SELECT * FROM tab", into(v)); 
    st.execute(true); /* with data exchange */ 
    unsigned int num_fields = v.size(); 
    std::cout << "fields: " << num_fields << std::endl; 
    num_fields = (num_fields <= 9) ? num_fields : 9; 
    unsigned long num_rows = (unsigned long)st.get_affected_rows(); 
    std::cout << "rows: " << num_rows << std::endl; 
for (size_t i = 0; i < num_fields; ++i) { 
      const soci::column_properties &props = v.get_properties(i); 
      std::string s = (std::string)props.get_name(); 
      int row; 
      soci::statement st = (mSql->prepare << "select " << props.get_name().c_str() <<" from map", soci::into(row)); 
      st.execute(); 
      while (st.fetch()) 
      { 
        std::stringstream ss; 
        ss << row; 
        std::string str = ss.str(); 
        cout<<str<<" "; 
      } 
      cout<<endl; 
    }