正在阅读：使用JDBC创建数据库访问程序使用JDBC创建数据库访问程序

            results = stmt.executeQuery("select * from  客户;");
            ResultSetMetaData resultMetaData = results.getMetaData();
            int cols = resultMetaData.getColumnCount();
            String resultRow = "";
            for (int i = 1; i < cols; i++) {
                resultRow += resultMetaData.getColumnName(i) + ";";
            }
            System.out.println(resultRow);
            while (results.next()) {
                resultRow = "";
                for (int i = 1; i < cols; i++) {
                    try {
                        resultRow += results.getString(i) + ";";
                    } catch (NullPointerException e) {
                        System.out.println(e.getMessage());
                    }
                }
                System.out.println(resultRow);
            }
        } catch (Exception e) {
            System.out.println("query exception");
        } finally {
            results.close();
        }
    }
  }