java - 尝试检索多个 JDBC 结果

Question

因此，我试图打印出我的程序中处理某些严重程度的医疗状况(高、中和低)的所有医院，这些医院是从我的程序的另一部分传递过来的。

最初，它会找到正确的严重级别，因此它会检查数据库中的另一个表以查找医院并打印它们。然而，它只打印其中一家医院(有两家医院的严重程度很高，我正在测试)，而不是另一家。

任何帮助将不胜感激，我觉得我的循环是错误的。

谢谢。

// Create selection query, get relevant hospitals
String select = "SELECT * FROM hospitals WHERE hospitalSeverityHandling = '" + medicalCondition + "'";


// Get results hospitals in the database
ResultSet results = statement.executeQuery(select);

// When hospitals have been found 

if (results.next())
{
    results.first();

    // Get hospitals with relevant severity
    //String hospital = results.getString("hospitalName");
    //System.out.println(hospital);

    // Respond to user, get hospital selection
    // TODO Hospital Selection
    JOptionPane.showMessageDialog(null, "A list of hospitals have been retrieved for severity level: " + medicalCondition, "Select available hospital", JOptionPane.INFORMATION_MESSAGE);   

    // Loop hospitals
    while(results.next())
    {
        String hospital = results.getString("hospitalName");
        System.out.println(hospital);
    }
}

Answer 1

您丢失了一条记录，因为您使用了 results.next() 两次。

相反，您可以按如下方式使用它:

   String select = "SELECT * FROM hospitals WHERE    
       hospitalSeverityHandling = '" + medicalCondition + "'";

    // Get results hospitals in the database
    ResultSet results = statement.executeQuery(select);

     // Loop hospitals
        while(results.next())
        {
            String hospital = results.getString("hospitalName");
            System.out.println(hospital);
        }
    }