java - 无法执行 hibernate 查询

Question

我有一个定义如下的实体类:

@Entity
@Table(name="user")
public class User implements Serializable{

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @NotNull
    @Column(name="email",nullable=false)
    @Size(min=5,max=15,message="Min 5 and Max 15")
    private String email;

    @NotNull
    @Column(name="password",nullable=false)
    @Size(min=5,max=15,message="Min 5 and Max 15")
    private String password;

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

我正在使用 HQL 创建一个 sql 查询，如下所示:

Query query = getSession().createSQLQuery("FROM User u where u.email = :email");
query.setString("email", username);
query.list();

调用 query.list() 时出现以下异常

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:91)
    at org.hibernate.loader.Loader.getResultSet(Loader.java:2066)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1863)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1839)
    at org.hibernate.loader.Loader.doQuery(Loader.java:910)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:355)
    at org.hibernate.loader.Loader.doList(Loader.java:2554)
    at org.hibernate.loader.Loader.doList(Loader.java:2540)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2370)
    at org.hibernate.loader.Loader.list(Loader.java:2365)
    at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:353)
    at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:1873)
    at org.hibernate.internal.AbstractSessionImpl.list(AbstractSessionImpl.java:311)
    at org.hibernate.internal.SQLQueryImpl.list(SQLQueryImpl.java:141)
    at com.revechat.spring.authentication.dao.UserDaoImpl.findByUserName(UserDaoImpl.java:25)
    at com.revechat.spring.authentication.service.UserServiceImpl.findByUserName(UserServiceImpl.java:26)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy39.findByUserName(Unknown Source)
    at com.revechat.spring.authentication.service.UserAuthDetailService.loadUserByUsername(UserAuthDetailService.java:30)
    at org.springframework.security.authentication.dao.DaoAuthenticationProvider.retrieveUser(DaoAuthenticationProvider.java:102)
    ... 42 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 'FROM User u where u.email = ''' at line 1
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
    at com.mysql.jdbc.Util.getInstance(Util.java:360)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:978)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3887)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3823)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2530)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1907)
    at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2030)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:82)
    ... 72 more

可能是什么问题？

Answer 1

Sql 查询需要有完整的sql 语法并且你使用的查询是HQL 查询

你的sql查询应该是这样的

你可以做到 getSession().createQuery("FROM User u where u.email = :email"); 或者 select * from <tableName> alias where email = ?