java.sql.SQLException：对空结果集的非法操作。对于选择语句

Question

我正在尝试从测试用例表中获取值，但它抛出 java.sql.SQLException: Illegal operation on empty result set 和 这是我的代码，

try {
            tcID=con.prepareStatement("select tc_id,tc_name from testcase where project_id=?  and tc_id=? ");
            tcID.setString(1,project);
            tcID.setString(2,tciD);
            ResultSet rs = tcID.executeQuery();
            System.out.println("Loop TC ID....."+rs.getString("tc_id"));
            System.out.println("Loop TC Name......"+rs.getString("tc_name"));
            while(rs.next()){
                System.out.println("Inside While.....");
                ps = con.prepareStatement("insert into execution_testcases (project_id, Rel_id, testcase_id, testcase_name, Flag) values(?,?,?,?,?)");
                ps.setString(1, project);
                ps.setString(2, RelName);
                ps.setString(3, rs.getString("tc_id"));
                ps.setString(4, rs.getString("tc_name"));
                ps.setString(5, "true");
                ps.executeUpdate();
            }
            String cmd= "java -jar D:\\FrameworkCodeDev\\Backups\\WebDriverJarFiles\\Build Release\\Framework_TAF_V10.jar";
            Runtime.getRuntime().exec(cmd);
        } catch (SQLException e) {          
            e.printStackTrace();
        }

谢谢。

Answer 1

如果没有数据，您将无法从ResultSet 中获取字符串。调用rs.getString()之前需要检查是否有数据，可以使用isBeforeFirst()进行。

    ResultSet rs = tcID.executeQuery();
    if(rs.isBeforeFirst()) {
        System.out.println("Loop TC ID....."+rs.getString("tc_id"));
        System.out.println("Loop TC Name......"+rs.getString("tc_name"));
        while(rs.next()){
            System.out.println("Inside While.....");
            ps = con.prepareStatement("insert into execution_testcases (project_id, Rel_id, testcase_id, testcase_name, Flag) values(?,?,?,?,?)");
            ps.setString(1, project);
            ps.setString(2, RelName);
            ps.setString(3, rs.getString("tc_id"));
            ps.setString(4, rs.getString("tc_name"));
            ps.setString(5, "true");
            ps.executeUpdate();
        }
    } else {
        System.out.println("No data in RS!");
    }

原答案链接：https://stackoverflow.com/a/6813771/1627055

Answer 2

当您尝试打印空结果集的元素时，问题出在您的 System.out.println 语句中。您应该尝试删除它们：

try {
    tcID=con.prepareStatement("select tc_id,tc_name from testcase where project_id=?  and tc_id=? ");
    tcID.setInt(1,project);
    tcID.setInt(2,tciD);
    ResultSet rs = tcID.executeQuery();

    while(rs.next()){
        System.out.println("Inside While.....");
        ps = con.prepareStatement("insert into execution_testcases (project_id, Rel_id, testcase_id, testcase_name, Flag) values(?,?,?,?,?)");
        ps.setString(1, project);
        ps.setString(2, RelName);
        ps.setString(3, rs.getString("tc_id"));
        ps.setString(4, rs.getString("tc_name"));
        ps.setString(5, "true");
        ps.executeUpdate();
    }
    String cmd= "java -jar D:\\FrameworkCodeDev\\Backups\\WebDriverJarFiles\\Build Release\\Framework_TAF_V10.jar";
    Runtime.getRuntime().exec(cmd);
} catch (SQLException e) {          
    e.printStackTrace();
}