在 mysql 中使用 hibernate cfg、xml 在 Z6B7B655DD22FAA3F1006777 中創建新表時出錯

Question

我在 src/main/resources 下收到此錯誤和 Log4j2.xml 以及 hibernate.cfg.xml，但我不確定為什么我會收到以下錯誤：

INFO: Server startup in 6322 ms
ERROR StatusLogger No log4j2 configuration file found. Using default configuration: logging only errors to the console. Set system property 'org.apache.logging.log4j.simplelog.StatusLogger.level' to TRACE to show Log4j2 internal initialization logging.
Hibernate: drop table if exists USERS_NEW
Hibernate: create table USERS_NEW (ID integer not null auto_increment, NAME varchar(255), TOTAL integer, GOAL integer, primary key (ID)) type=MyISAM
Hibernate: insert into USERS_NEW (NAME, TOTAL, GOAL) values (?, ?, ?)
12:06:53.426 [http-nio-8080-exec-2] ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Table 'studentdb.users_new' doesn't exist
Feb 08, 2021 12:06:53 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [InitHibernate] in context with path [/protein-tracker-xml] threw exception
org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:63)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:200)
    at org.hibernate.dialect.identity.GetGeneratedKeysDelegate.executeAndExtract(GetGeneratedKeysDelegate.java:57)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:43)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3200)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3806)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:84)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:645)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:282)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:263)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:317)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:330)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:287)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:123)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:194)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:179)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)

這是servlet代碼

package com.simplilearn.workshop;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    
    import com.simplilearn.workshop.model.User;
    import com.simplilearn.workshop.util.HibernateUtil;
    
    //@WebServlet("/init")
    public class InitHibernate extends HttpServlet {
        private static final long serialVersionUID = 1L;
    
       
        public InitHibernate() {
            // TODO Auto-generated constructor stub
        }
    
        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            try {
                    PrintWriter out = response.getWriter();
                    out.println("<html><body>");
    
                    SessionFactory factory = HibernateUtil.getSessionFactory();
                    //retrieve a hibernate session       
                    Session session = factory.openSession();
                    out.println("Hibernate Session opened.<br>");
                    out.println("Saving User Data..... .<br>");
                    
                    //begin new transaction
                    session.beginTransaction();
                    
                    User user = new User();
                    //user.setId(2);
                    user.setName("max");
                    user.setGoal(290);
                    user.setTotal(250);
                  
                    //execute database operation
                    session.save(user);
                    
                    
                    // commit transaction
                    session.getTransaction().commit();
                    out.println("User Data is Saved.<br>");
                    
                    // flush and close session
                    session.close();
                    out.println("Hibernate Session closed.<br>");
                    
                    
                    //session.beginTransaction();
                    
                     
                   //User loadedUser = (User)session.get(User.class, 1);
                    //out.println("Name : " + loadedUser.getName() + "<br/>");
                   // out.println("Goal : " + loadedUser.getGoal() + "<br/>");
                    
                    //manipulate the loaded user
                    //loadedUser.setTotal(loadedUser.getTotal() + 50);
                    
                    //session.getTransaction().commit(); // auto updating
                    
                    //Flush and Close Session
                    
                   
                    
                    out.println("</body></html>");
                       
                        
            } catch (Exception ex) {
                throw ex;
            }
    
        }
    
        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            // TODO Auto-generated method stub
            doGet(request, response);
        }
    
    }

Answer 1

在.xml 或.properties 文件中更改設置時清理項目。 在 eclipse 環境中。