Question

我正在尝试获取与月份列完全匹配的记录（这是id列）但我没有得到匹配记录。我在sql db中执行了这样的查询“从webSheet中选择表单month ='Feb'“它被执行。在HQL中它不起作用..

我的堆栈流程：

INFO: table found: soft.dbo.employee
SHEET DAO CLASS
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
Retrieve Sheet:::::::Feb
INFO: columns: [empid, time, empname]
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: foreign keys: []
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: indexes: [pk__employee__73a521ea]
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: table found: soft`enter code here`.dbo.webSheet
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: columns: [month, sheet]
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: foreign keys: []
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.TableMetadata <init>
INFO: indexes: [pk__websheet__69279377]
Nov 18, 2011 12:57:12 PM org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: schema update complete
Hibernate: select websheet0_.sheet as col_0_0_ from webSheet websheet0_ where websheet0_.month=Feb
Error-->could not execute query
In opensheet class-->result
Nov 18, 2011 12:57:13 PM org.hibernate.util.JDBCExceptionReporter logExceptions
WARNING: SQL Error: 207, SQLState: S0001
Nov 18, 2011 12:57:13 PM org.hibernate.util.JDBCExceptionReporter logExceptions
SEVERE: Invalid column name 'Feb'.

我的代码如下：DataAccessDAO.java

 try{
       Session session=sessionFactory.openSession();
       WebSheet ws=new WebSheet();
       ws.setMonth(month);
        txn=session.beginTransaction();
        query=session.createQuery("select ws.sheet from WebSheet as ws where ws.month="+month).list();

        System.out.println("result::::::::::"+query.size());
        String result=query.iterator().next().getSheet();

    }
    catch(Exception ex){
        System.err.println("Error-->"+ex.getMessage());
        if(txn!=null){
          txn.rollback();
        }
    }

我的映射文件：

<hibernate-mapping>
<class name="com.MyApp.beans.WebSheet" table="webSheet">
 <id name="month" type="string">
   <generator class="assigned"/>
 </id>
 <property name="sheet" type="string"/>
 </class>
 </hibernate-mapping>

我的Pojo课程：

public class WebSheet {
   private String month;
   private String sheet;
   /*setters and getters*****

Answer 1

查询应该是这样的 -

Query query = session.createQuery("from com.MyApp.beans.WebSheet as ws where ws.month=:mth");

query.setParameter("mth", month);

WebSheet wsObj = null;
String sheet = null;

Iterator it = query.iterate(); it.hasNext();{
     wsObj = (WebSheet) it.next();
}
if(wsObj != null){
sheet = wsObj.getSheet();
}
session.getTransaction().commit();

Answer 2

正确的方式是@anirudhamundada说。

但是如果你想继续做错和不安全，你必须添加：

query=session.createQuery("select ws.sheet from WebSheet as ws where ws.month='"+month + "'").list();

您似乎没有返回String。

尝试

Object o = query.iterator().next().getSheet();
System.out.println(o.getClass().getName());

什么类型？

Hibernate给出以下错误：错误 - ＆gt;无法执行查询

2 个答案: