Question

我有一个问题 - 我是hibernate的新手，需要转换一个由executing session.createSQLQuery(query).list()命令返回的表。我试图添加addEntity(Result.class)命令，但程序抛出异常：

Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.MappingException: Unknown entity: com.hib.entities.Result

我在mysql中的结果表如下所示：

| bookName | authorSurname | authorFirstName | authorPatronymic | releaseDate | amountBooks|

我试图创建Entity类Result并对其进行注释，但似乎我失败了。我的实体类看起来像这样：

package com.hib.entities;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table
public class Result {

    String bookName;
    String authorSurname;
    String authorFirstName;
    String authorPatronymic;
    Integer releaseDate;
    Integer amountBooks;

    public Result(String bookName, String authorSurname, String authorFirstName, String authorPatronymic, Integer releaseDate, Integer
            amountBooks) {
        this.bookName = bookName;
        this.authorSurname = authorSurname;
        this.authorFirstName = authorFirstName;
        this.authorPatronymic = authorPatronymic;
        this.releaseDate = releaseDate;
        this.amountBooks = amountBooks;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public void setAuthorSurname(String authorSurname) {
        this.authorSurname = authorSurname;
    }

    public void setAuthorFirstName(String authorFirstName) {
        this.authorFirstName = authorFirstName;
    }

    public void setAuthorPatronymic(String authorPatronymic) {
        this.authorPatronymic = authorPatronymic;
    }

    public void setReleaseDate(Integer releaseDate) {
        this.releaseDate = releaseDate;
    }

    public void setAmountBooks(Integer amountBooks) {
        this.amountBooks = amountBooks;
    }

    public String getBookName() {
        return bookName;
    }

    public String getAuthorSurname() {
        return authorSurname;
    }

    public String getAuthorFirstName() {
        return authorFirstName;
    }

    public String getAuthorPatronymic() {
        return authorPatronymic;
    }

    public Integer getReleaseDate() {
        return releaseDate;
    }

    public Integer getAmountBooks() {
        return amountBooks;
    }

    @Override
    public String toString() {
        return "Result{" +
                "bookName='" + bookName + '\'' +
                ", authorSurname='" + authorSurname + '\'' +
                ", authorFirstName='" + authorFirstName + '\'' +
                ", authorPatronymic='" + authorPatronymic + '\'' +
                ", releaseDate=" + releaseDate +
                ", amountBooks=" + amountBooks +
                '}';
    }
}

你能帮我解决这个问题吗？

Answer 1

您必须区分session.createQuery(query)和session.createSQLQuery(query) 如果您使用session.createQuery(query)，您的查询将以HQL（与SQL非常相似）编写，您可以这样做

Query q = session.createQuery(query) List<Result> myResultList = q.list();

但是

如果您想使用session.createSQLQuery(query)，则必须使用此

List<Result> myResultList = session.createSQLQuery(query).setResultTransformer(
    Transformers.aliasToBean(Result.class)).list();

我个人建议你使用session.createQuery(query)，这样你就可以受益于hibernate映射的优点

在这个link中，您将找到有关Hibernate上下文中HQL与SQL之间差异的更多解释。

将默认的hibernate createSQLQuery转换为自制类列表

1 个答案: