java - 如何获取 ResultSet 的整数值并将其分配给 int 变量？

Question

int bookID 返回值 0，它应该返回 1。 (表中的第一个 ID。)请帮忙。

public void ID(){

   conn = ConnectDB();

   String sql = "Select Book_ID From Student Biblio";
   try {
       pst = conn.prepareStatement(sql);
       rs = pst.executeQuery();

       if(rs.next()){
        int bookID = rs.getInt(1); //IDTable


       }

   } catch (SQLException ex) {
       Logger.getLogger(Student.class.getName()).log(Level.SEVERE, null, ex);
   }
}

Answer 1

试试这个可能会对你有帮助

public void ID(){

   conn = ConnectDB();

   String sql = "Select Book_ID From Student Biblio";
   try {
       pst = conn.prepareStatement(sql);
       rs = pst.executeQuery();

       while(rs.next()){
        int bookID = rs.getInt("Book_ID"); //IDTable


       }

   } catch (SQLException ex) {
       Logger.getLogger(Student.class.getName()).log(Level.SEVERE, null, ex);
   }
}