答复: Selecting a key value pair

[smartkid]

Use "System.Collections.IDictionary" as the resultClass for "SelectDescLCID"


-----邮件原件-----
发件人: Andrea Tassinari [mailto:[EMAIL PROTECTED] 
发送时间: 2008年1月10日 19:08
收件人: user-cs@ibatis.apache.org
主题: Selecting a key value pair 

Hello,

The problem:

I have a class like this:

public class Item
{
   private int _id;
   private HashTable _desc;

   public Item()
   {
     _id = 0;
     _desc = new HashTable();
   }

   public int Id
   {
       get{return _id;}
       set{_id=value;}
   }

   //this represents a set of key,value  of localized strings, for instance
   // "it-IT", "Buongiorno"
   // "en-US", "Good Morning"
   // "fr-FR", "Bonjour"
   // an so on
   public HashTable Desc
   {
       get{return _desc;}
       set{_desc = value; }
   }
}

//client code example
Item item = _mapper.QueryForObject("SelectItem", itemid);

string LCID = "en-US"; //actually this is parameterezid elsewhere.

//this is what I would have
string englishDescription = (string)item.Desc[LCID];

//even better: a KeyPairValue<string,string> for property Desc, which
//would lead to //drop the explicit string cast
string englishDescription = item.Desc[LCID];


Database Tables examples

table ITEMS
  itemId 
  partNumber
  streetPrice
  etc etc
PK(intemID)

table ITEMDESC
  itemId  //foreign key to column itemId of table ITEMS
  LCID    
  Description
PK(itemId, LCID)


Now, how could this be done with iBatis? It would be nice to have a mapping
like this:

<resultMap id="ItemResul" class="Item">
   <result property="Id" column="Id" type="int" dbType="Int"/>
   <result property="Desc" column="Id" select="SelectDescLCID"
lazyload="false"/>
</resultMap>

<select id="SelectItem" parameterClass="string" resultMap="ItemResul">
   SELECT intemId AS Id, partNumber AS PartNumber
   FROM items
   WHERE itemId=#value#
</select>

<select id="SelectDescLCID" parameterClass="string" resultmap="?????">
   SELECT LCID as Key, Descr as Value
   FROM ITEMDESC
   WHERE itemId=#value#
</select>

Is there a way to achive this? 

Thank you

Cheers,
Andrea