小编rai*_*inu的帖子

我正在使用Apache Derby数据库和ij 10.10.

我有2个表首先是'usertable',第二个是'logintable'.在我的'usertable'中,我有两列userid和name.我的'logintable'表有两列userid和password.我需要在logintable中将一列设置为外键,其中主键位于用户表中.

我使用命令以下命令来创建表:

create table usertable (userid varchar(10) primary key,name varchar(20));

如何编写logintable以将userid设置为引用上述主键的外键.

任何人都可以帮助我.

我正在尝试做一个简单的休眠程序.我按照本教程中给出的步骤操作.

我得到的错误是

   org.hibernate.MappingNotFoundException: resource: org.manu.dtd.UserDetails not found
    at org.hibernate.cfg.Configuration.addResource(Configuration.java:799)
    at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:2344)
    at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:2310)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2290)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2243)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:2158)
    at org.manu.dtd.TestHibernate.main(TestHibernate.java:16)

这是我的文件夹结构

我的带注释的persitence类是

package org.manu.dtd;

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

@Entity
public class UserDetails {

    @Id
    private int userId;

    private String userName;
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }

}

我的hibernate.cfg.xml文件是

<?xml version='1.0' encoding='utf-8'?> …

我正在获取ojbc14.jar文件中存在的类oracle.jdbc.driver.OracleDriver的ClassNotFoundException.我已经找到了这个问题的答案,但没有解决方案有效.我的项目结构如下.

有人建议通过右键单击项目 - >构建路径 - >配置构建路径 - >添加外部jar来添加ojdbc14.jar文件.我已经这样做但仍然在eclipse中的服务器窗口中得到错误.

java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1854)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1703)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:259)
at com.ars.util.DBConnection.getCon(DBConnection.java:20)
at com.ars.dao.UserLoginDAO.checkUserLoginDetails(UserLoginDAO.java:18)
at com.ars.handler.UserLoginHandler.doPost(UserLoginHandler.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:748)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:486)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:411)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:338)
at com.ars.controller.ARSController.doPost(ARSController.java:110)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at …