使用＆＃34; Count＆＃34;在PreparedStatement中......给出相同的结果

Question

我得到了相同的总数（这是不正确的）＆＃34; Count＆＃34;在下面的代码中。如果我使用＆＃34; Statement＆＃34;，则总数是正确的。控制台上显示的错误结果是......

运行：

Connection Successful
Members 500
Payment 500
BUILD SUCCESSFUL (total time: 0 seconds)

package preparedstatement2;

import java.sql.*;

public class Main {

    public static void main(String[] args) {

        Connection conn = SqliteConn.connectDB();
        try {
            PreparedStatement pst = conn.prepareStatement("Select Count (?) From members");
            pst.setString(1, "mem_id");
            ResultSet rs = pst.executeQuery();
            while (rs.next()) {
                int mem_id = rs.getInt(1);
                System.out.println("Members " + mem_id);
            }

            pst.setString(1, "payment");
            rs = pst.executeQuery();
            while (rs.next()) {
                int payment = rs.getInt(1);
                System.out.println("Payment " + payment);
            }

        } catch (SQLException ex) {
            ex.getMessage();
        }
    }
}

编辑： 预期的输出应该是：

Connection Successful
Members 500
Payment 400
BUILD SUCCESSFUL (total time: 0 seconds)