org.hibernate.exception.SQLGrammarException：无法执行语句 [英] org.hibernate.exception.SQLGrammarException: could not execute statement

问题描述

我找不出什么错误。

我有三个类 - Book，Reader和Using。最后一个是绑定前两个依赖关系的一对多。

这是我的 main（）：

  public class Appl {
 public static void main（String [] args）{
 Book book = new Book（ ）; 
 book.setTitle（book01155）; 
 // 
读者阅读器= new Reader（）; 
 reader.setName（reader2）; 
 // 
使用using = new Using（）; 
 using.setIdBook（book）; 
 using.setIdReader（reader）; 
 // 
列表< Book> elements = new ArrayList< Book>（）; 
 // 
会话会话= null; 
 try {
 session = HibernateUtil.getSessionFactory（）。openSession（）; 
 session.beginTransaction（）; 
 session.save（book）; 
 session.save（reader）; 
 session.save（using）; 
 elements = session.createCriteria（Book.class）.list（）; 
 session.getTransaction（）。commit（）; 
} finally {
 if（session！= null&& session.isOpen（））{
 session.close（）; 
 
 
（Book b：elements）{
 System.out.println（book：id =+ b.getIdBook（）+Title =
 + b.getTitle（））; 
} 
 System.out.println（\\\
The END.\\\
）; 
 
 
 $ / code $ / pre 
 
 
以下是异常消息：
 
 
 错误：您的SQL语法有错误;检查与您的MySQL服务器版本相对应的手册，以便在第1行中使用'USING（IDBOOK，IDREADER）值（2，2）'附近的正确语法
线程mainorg.hibernate.exception中的异常。 SQLGrammarException：在org.hibernate.exception.internal.StandardSQLExceptionConverter.convert（StandardSQLExceptionConverter.java在org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert无法执行的语句
（SQLExceptionTypeDelegate.java:82）
： 49）
 at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert（SqlExceptionHelper.java:125）
  
 
 
 
 hiberante.cfg.xml ：
 <冬眠-结构> 
< session-factory> 
< property name =eclipse.connection.profile> 097Hibernate< / property> 
 
< property name =connection.url> jdbc：mysql：// localhost / _097_Library< / property> 
< property name =connection.username> root< / property> 
< property name =connection.password>秘密< / property> 
 
 <！ -  property name =hbm2ddl.auto> create< / property  - > 
< property name =hbm2ddl.auto>更新< / property> 
 
< property name =connection.driver_class> 
 com.mysql.jdbc.Driver 
< / property> 
 
< property name =dialect> 
 org.hibernate.dialect.MySQLDialect 
< / property> 
 
< mapping class =com.softserve.edu.Book/> 
< mapping class =com.softserve.edu.Reader/> 
< mapping class =com.softserve.edu.Using/> 
< / session-factory> 
< / hibernate-configuration> 
  
 DB中的所有表格都已创建，但为空。 
所有看起来都不错。任何建议？
 
 
 
 
 
  如何解决这个问题？  
 $在MySQL中 USING 是    mysql.com/doc/mysqld-version-reference/en/mysqld-version-reference-reservedwords-5-0.htmlrel =noreferrer>保留字。
 
 
 
因此，只需在使用实体上使用 @ javax.persistence.Table 注释重命名表。 
类似于 
 
 
  @Entity 
 @Table（name =TB_USING）
 public类使用{
 ... 
} 
  
我假设你有一张桌子对于 USING ，但您提到它是一对多关系，因此您可以省略该表，并使用<$ c中的一个外键对其进行建模$ c> Reader 表。
 
 
 
顺便提一下，hibernate不会强制您为多对多连接表创建一个新实体除了外键之外，它没有任何其他属性）。但我认为有一个关系实体是一个很好的习惯，因为大多数情况下，将来会为关系定义一些属性。
 
I tried easy program at Hibernate and caught bunch of exception.

I couldn't figure out what exactly is wrong.

I have three classes - Book, Reader and Using. The last is binding first two with dependency one to many.

Here is my main():
public class Appl {
    public static void main(String[] args) {
        Book book = new Book();
        book.setTitle("book01155");
        //
        Reader reader = new Reader();
        reader.setName("reader2");
        //
        Using using = new Using();
        using.setIdBook(book);
        using.setIdReader(reader);
        //
        List<Book> elements = new ArrayList<Book>();
        //
        Session session = null;     
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            session.beginTransaction();
            session.save(book);
            session.save(reader);
            session.save(using);
            elements = session.createCriteria(Book.class).list();
            session.getTransaction().commit();
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
        for (Book b : elements) {
            System.out.println("book: id=" + b.getIdBook() + " Title="
                    + b.getTitle());
        }
        System.out.println("\nThe END.\n");
    }
}
Here is exception message:
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'USING (IDBOOK, IDREADER) values (2, 2)' at line 1
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:82)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
snippet of hiberante.cfg.xml:
<hibernate-configuration>
    <session-factory>
        <property name="eclipse.connection.profile">097Hibernate</property>

        <property name="connection.url">jdbc:mysql://localhost/_097_Library</property>
        <property name="connection.username">root</property>
        <property name="connection.password">secret</property>

        <!-- property name="hbm2ddl.auto">create</property -->
        <property name="hbm2ddl.auto">update</property>

        <property name="connection.driver_class">
            com.mysql.jdbc.Driver
        </property>

        <property name="dialect">
            org.hibernate.dialect.MySQLDialect
        </property>

        <mapping class="com.softserve.edu.Book" />
        <mapping class="com.softserve.edu.Reader" />
        <mapping class="com.softserve.edu.Using" />
    </session-factory>
</hibernate-configuration>
All tables at DB are created but is empty.
All looks ok. Any suggestions?


How to solve this trouble?

解决方案
In MySQL USING is reserved word.

So just rename the table by using @javax.persistence.Table annotation on your Using entity.
Something like
@Entity
@Table(name = "TB_USING")
public class Using {
    ...
}
I assumed you have a table for USING, but you mentioned that it is a one-to-many relationship, so you can omit the table, and model it using just a single foreign key in Reader table.

By the way hibernate does not force you to create a new entity for many-to-many join tables (which don't have any more attribute but the foreign keys). But I believe it is a good practice to have an entity for that relationship, cause most of the times some attributes will be defined for the relation in future.

                        
这篇关于org.hibernate.exception.SQLGrammarException：无法执行语句的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！