我有一个问题 - 我是 hibernate 的新手，需要转换一个表，由 执行 session.createSQLQuery(query).list() 命令返回。 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|

我尝试创建实体类 Result 并对其进行注释，但似乎我失败了。 我的实体类如下所示:

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？

最佳答案

你要区分session.createQuery(query)和 session.createSQLQuery(query) 如果你使用 session.createQuery(query)您的查询将写入 HQL (这与 SQL 非常相似)，您将能够这样做

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

但是

如果你想使用session.createSQLQuery(query)你必须使用这个

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

我个人建议您使用 session.createQuery(query)这样您就可以利用 hibernate 映射的优势

在此link您会在 hibernate 上下文中找到有关 HQL 和 SQL 之间区别的更多解释。

关于java - 将默认的 hibernate createSQLQuery 转换为自制类的列表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45536463/