我正在开发一个hibernate JPA项目，我正面对上面提到的异常，它告诉我的SQL语法不好几乎我很确定我的hibernate配置与我的MySQL数据库，任何人都可以帮我弄清楚问题是什么吗？这是一些代码：
UsersHome.java
public class UsersHome {
private static final Log log = LogFactory.getLog(UsersHome.class);
@PersistenceContext(unitName = "saddem")
EntityManagerFactory emf = Persistence.createEntityManagerFactory("saddem");
private EntityManager entityManager = emf.createEntityManager();
public void persist(Users transientInstance) {
log.debug("persisting Users instance");
try {
entityManager.persist(transientInstance);
log.debug("persist successful");
} catch (RuntimeException re) {
log.error("persist failed", re);
throw re;
}
}
public void remove(Users persistentInstance) {
log.debug("removing Users instance");
try {
entityManager.remove(persistentInstance);
log.debug("remove successful");
} catch (RuntimeException re) {
log.error("remove failed", re);
throw re;
}
}
public Users merge(Users detachedInstance) {
log.debug("merging Users instance");
try {
Users result = entityManager.merge(detachedInstance);
log.debug("merge successful");
return result;
} catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
}
public Users findById(Integer id) {
log.debug("getting Users instance with id:" + id);
try {
Users instance = entityManager.find(Users.class, id);
log.debug("get successful");
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
// Query query = entityManager.createNamedQuery("users.findById");
// query.setParameter("userid", id);
// Users us=(Users) query.getSingleResult();
// return us;
}
public List<Users> findAll() {
log.debug("getting all User instances");
try {
Query query = entityManager.createQuery("select u from Users u");
List<Users> usersList = (List<Users>) query.getResultList();
log.debug("findAll successful");
return usersList;
} catch (RuntimeException re) {
log.error("findAll failed", re);
return new ArrayList<Users>();
}
// Query query = entityManager.createNamedQuery("users.findAll");
// List<Users> usersList = (List<Users>) query.getResultList();
// return usersList;
}
}
Users.java
@Entity
//@NamedQuery(name="users.findById",query="SELECT u FROM Users u WHERE u.userid = :userid")
//@NamedQuery(name="users.findAll",query="SELECT FROM Users u")
@Table(name = "users", catalog = "user")
public class Users implements java.io.Serializable {
private Integer userid;
private Address address;
private String username;
private String password;
private String firstname;
private String lastname;
private String email;
public Users() {
}
public Users(Address address, String username, String password,
String firstname, String lastname, String email) {
this.address = address;
this.username = username;
this.password = password;
this.firstname = firstname;
this.lastname = lastname;
this.email = email;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "userid", unique = true, nullable = false)
public Integer getUserid() {
return this.userid;
}
public void setUserid(Integer userid) {
this.userid = userid;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "addressid")
public Address getAddress() {
return this.address;
}
public void setAddress(Address address) {
this.address = address;
}
@Column(name = "username")
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
@Column(name = "password", length = 64)
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
@Column(name = "firstname")
public String getFirstname() {
return this.firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
@Column(name = "lastname")
public String getLastname() {
return this.lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
@Column(name = "email")
public String getEmail() {
return this.email;
}
public void setEmail(String email) {
this.email = email;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Users [userid=" + userid + ", username=" + username
+ ", password=" + password + ", firstname=" + firstname
+ ", lastname=" + lastname + ", email=" + email + "]";
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((address == null) ? 0 : address.hashCode());
result = prime * result + ((email == null) ? 0 : email.hashCode());
result = prime * result + ((firstname == null) ? 0 : firstname.hashCode());
result = prime * result + ((lastname == null) ? 0 : lastname.hashCode());
result = prime * result + ((password == null) ? 0 : password.hashCode());
result = prime * result + ((userid == null) ? 0 : userid.hashCode());
result = prime * result + ((username == null) ? 0 : username.hashCode());
return result;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Users other = (Users) obj;
if (address == null) {
if (other.address != null)
return false;
} else if (!address.equals(other.address))
return false;
if (email == null) {
if (other.email != null)
return false;
} else if (!email.equals(other.email))
return false;
if (firstname == null) {
if (other.firstname != null)
return false;
} else if (!firstname.equals(other.firstname))
return false;
if (lastname == null) {
if (other.lastname != null)
return false;
} else if (!lastname.equals(other.lastname))
return false;
if (password == null) {
if (other.password != null)
return false;
} else if (!password.equals(other.password))
return false;
if (userid == null) {
if (other.userid != null)
return false;
} else if (!userid.equals(other.userid))
return false;
if (username == null) {
if (other.username != null)
return false;
} else if (!username.equals(other.username))
return false;
return true;
}
}
MainTest.java
public class MainTest {
/**
* @param args
*/
public static void main(String[] args) {
//TODO Auto-generated method stub
UsersHome dao = new UsersHome() ;
Users us = dao.findById(1);
System.out.println("-Livre :"+us.getFirstname());
}
}
==＆GT;例外：
log4j:WARN No appenders could be found for logger (org.jboss.logging).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Hibernate: select users0_.userid as userid1_1_0_, users0_.addressid as addressi7_1_0_, users0_.email as email2_1_0_, users0_.firstname as firstnam3_1_0_, users0_.lastname as lastname4_1_0_, users0_.password as password5_1_0_, users0_.username as username6_1_0_ from user.user.users users0_ where users0_.userid=?
Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not extract ResultSet
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1763)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1694)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1141)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1068)
at com.sad.db.dao.UsersHome.findById(UsersHome.java:72)
at com.sad.db.dao.MainTest.main(MainTest.java:21)
Caused by: org.hibernate.exception.SQLGrammarException: could not extract ResultSet
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:80)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:126)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:112)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:89)
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.getResultSet(AbstractLoadPlanBasedLoader.java:449)
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeQueryStatement(AbstractLoadPlanBasedLoader.java:202)
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:137)
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:102)
at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:186)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:4120)
at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:502)
at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:467)
at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:212)
at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:274)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:150)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1066)
at org.hibernate.internal.SessionImpl.access$2000(SessionImpl.java:176)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2540)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:951)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1110)
... 3 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: 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 '.users users0_ where users0_.userid=1' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1053)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2719)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2318)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:80)
... 19 more