由于:java.sql.SQLException:未找到列'id'

6

我希望获取一些字段并将其设置到我的Test.entity中。我的SQL查询:

                query = "SELECT t.id as tId, t.test_name, t.duration, q.id as qId, " +
                    "q.question as question, q.is_multichoice as is_multichoice, " +
                    "q.is_open as is_open, a.id as aId, a.answer_text as answer_text  FROM result r " +
                    "JOIN test t ON r.test_id = t.id " +
                    "JOIN user u ON r.user_id = u.id " +
                    "JOIN question q ON t.id = q.test_id JOIN answer a ON q.id = a.question_id " +
                    "WHERE t.id = :testId AND u.id = :userId AND r.permission = :permissionId " +
                    "AND q.archived = false AND a.archived = false", resultClass = com.bionic.entities.Test.class)

测试实体:

public class Test {
@Id
@Column(name = "id")
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@Column(name = "duration", nullable = false)
private int duration;
@Column(name = "test_name", nullable = false, unique = true)
private String testName;
@Column(name = "archived", nullable = false)
private boolean archived;
@OneToMany(mappedBy = "test", fetch = FetchType.EAGER)
private Set<Question> questions;
@ManyToMany(mappedBy = "tests")
private Set<User> users;

问题实体:

public class Question {
@Id
@Column(name = "id")
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@Column(name = "is_multichoice", nullable = false)
private boolean isMultichoice;
@Column(name = "is_open", nullable = false)
private boolean isOpen;
@Column(name = "picture")
private String picture;
@Column(name = "question")
private String question;
@ManyToOne
@JoinColumn(name = "test_id", nullable = false)
private Test test;
@Column(name = "archived", nullable = false)
private boolean isArchived;
@OneToMany(mappedBy = "question", fetch = FetchType.EAGER)
private Set<Answer> answers;

答案实体:

public class Answer {
@Id
@Column(name = "id")
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@Column(name = "answer_text", nullable = false)
private String answerText;
@Column(name = "mark", nullable = false)
private int mark;
@ManyToOne
@JoinColumn(name = "question_id")
private Question question;
@Column(name = "picture")
private String picture;
@Column(name = "archived", nullable = false)
private boolean isArchived;

然而,在执行此查询后,我遇到了异常:
Caused by: java.sql.SQLException: Column 'id' not found.

DAO.class:

    public Test getCurrentTest(long id, long testId, long permissionId) {
    Query query = em.createNamedQuery("getCurrentTestById");
    query.setParameter("userId", id);
    query.setParameter("testId", testId);
    query.setParameter("permissionId", permissionId);
    return (Test) query.getSingleResult();
}

我做错了什么?


请确保您的所有表都有名为__id__的列。 - gauee
1个回答

8

您的查询没有返回名为id的字段。它有名为aId、qId和tId的字段。

您需要在实体中使用正确的列名。例如,在您的Test实体中,您声明了一个名为id的列。但是您的查询并没有返回名为id的列,而是返回名为tId的列。请参见下面的示例以了解需要更改的内容。

public class Test {
@tId
@Column(name = "tId")
@GeneratedValue(strategy = GenerationType.AUTO)
private long tId;
 .... 

我该如何将它映射到实体中的ID字段? - quento
我的意思是我有3个名为id的字段(test,question,answer),但我无法通过SQL查询获取具有相同名称“id”的3个字段。 - quento
我理解了。这就是你给这三个字段起别名的原因。从而改变字段的名称,使它们成为唯一的。但这也意味着你的代码看不到一个名为“id”的字段。你需要按照它的新别名引用该字段。 - Rabbit
我应该使用SqlResultSetMappings还是在每个实体中重命名字段(我不喜欢这种变体)?如果我应该使用SqlResultSetMappings,那么如何将答案和问题的字段设置为它们是子实体? - quento
我不知道你的意思是什么。你的参考资料含糊不清。我编辑了帖子并添加了更多信息,希望这能为你澄清一些事情。 - Rabbit
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