Index: core/xwiki-core/src/main/java/com/xpn/xwiki/api/XWiki.java
===================================================================
--- core/xwiki-core/src/main/java/com/xpn/xwiki/api/XWiki.java	(revision 24111)
+++ core/xwiki-core/src/main/java/com/xpn/xwiki/api/XWiki.java	(working copy)
@@ -25,6 +25,7 @@
 import java.util.Collections;
 import java.util.Date;
 import java.util.List;
+import java.util.HashMap;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -36,6 +37,7 @@
 import com.xpn.xwiki.XWikiException;
 import com.xpn.xwiki.doc.XWikiDeletedDocument;
 import com.xpn.xwiki.doc.XWikiDocument;
+import com.xpn.xwiki.doc.XWikiAttachment;
 import com.xpn.xwiki.objects.meta.MetaClass;
 import com.xpn.xwiki.plugin.query.XWikiCriteria;
 import com.xpn.xwiki.plugin.query.XWikiQuery;
@@ -565,6 +567,120 @@
     }
 
     /**
+     * Search attachments by passing HQL where clause values as parameters. See
+     * {@link #searchDocuments(String, int, int, List)} for more about parameterized hql clauses.
+     * You can specify properties of attach (the attachment) or doc (the document it is attached to)
+     * 
+     * @param parametrizedSqlClause The HQL where clause. For example <code>" where doc.fullName
+     *        <> ? and (attach.author = ? or (attach.filename = ? and doc.space = ?))"</code>
+     * @param nb The number of rows to return. If 0 then all rows are returned
+     * @param start The number of rows to skip at the beginning.
+     * @param parameterValues A {@link java.util.List} of the where clause values that replace the question marks (?)
+     * @return A List of {@link Attachment} objects.
+     * @throws XWikiException in case of error while performing the query
+     */
+    public List<Attachment> searchAttachments(String parametrizedSqlClause, int nb, int start, List< ? > parameterValues)
+        throws XWikiException
+    {
+        //get the attachment filenames and document fullNames
+        List<java.lang.Object[]> results = this.xwiki.getStore().search(
+            "select attach.filename, doc.fullName from XWikiAttachment attach, XWikiDocument doc where doc.id = attach.docId and "
+             + parametrizedSqlClause, nb, start, parameterValues, this.context);
+
+        HashMap<String, List<String>> filenamesByDocFullName = new HashMap<String, List<String>>();
+
+        //put each attachment with the document it belongs to
+        for(int i=0; i<results.size(); i++){
+            String filename = (String) results.get(i)[0];
+            String DocFullName = (String) results.get(i)[1];
+            if(!filenamesByDocFullName.containsKey(DocFullName)){
+                filenamesByDocFullName.put(DocFullName, new ArrayList<String>());
+            }
+            filenamesByDocFullName.get(DocFullName).add((String) filename);
+        }
+
+        List<Attachment> out = new ArrayList<Attachment>();
+
+        //index through the document names
+        for(String fullName : filenamesByDocFullName.keySet()){
+            //get the documents
+            Document doc = getDocument(fullName);
+            //index through the attachments
+            for(String filename : filenamesByDocFullName.get(fullName)){
+                //get the attachments from the document (they already have their "doc" value set)
+                Attachment attach = doc.getAttachment(filename);
+                //add the attachment to the output
+                out.add(attach);
+            }
+        }
+
+        return out;
+    }
+
+    /**
+     * API allowing to search for attachments matching a query return only a limited number of elements and skipping
+     * the first rows.
+     * 
+     * @param whereSql Query to use similar to {@link #searchDocuments(String)}
+     * @param nb Number of rows to return
+     * @param start Skip the first (start) rows
+     * @return A List of {@link Attachment} objects.
+     * @throws XWikiException
+     * @see #searchAttachments(String, int, int, List)
+     */
+    public List<Attachment> searchAttachments(String whereSql, int nb, int start)
+        throws XWikiException
+    {
+        return searchAttachments(whereSql, nb, start, null);
+    }
+
+    /**
+     * API allowing to search for attachments matching a query return only a limited number of elements and skipping
+     * the first rows. The query part is the same as {@link #searchAttachments(String, int, int, List)}
+     * 
+     * @param whereSql Query to use similar to {@link #searchDocuments(String)}
+     * @return A List of {@link Attachment} objects.
+     * @throws XWikiException
+     */
+    public List<Attachment> searchAttachments(String whereSql)
+        throws XWikiException
+    {
+        return searchAttachments(whereSql, 0, 0, null);
+    }
+
+    /**
+     * Count attachments returned by a given parameterized query
+     *
+     * @param parametrizedSqlClause Everything which would follow the "WHERE" in HQL see: {@link #searchDocuments(String, int, int, List)}
+     * @param parameterValues A {@link java.util.List} of the where clause values that replace the question marks (?)
+     * @return int number of attachments found.
+     * @throws XWikiException
+     * @see #searchAttachments(String, int, int, List)
+     */
+    public int countAttachments(String parametrizedSqlClause, List< ? > parameterValues)
+        throws XWikiException
+    {
+        List l = this.xwiki.getStore().search(
+            "select count(attach) from XWikiAttachment attach, XWikiDocument doc where doc.id = attach.docId and "
+             + parametrizedSqlClause, 0, 0, parameterValues, this.context);
+        return ((Number) l.get(0)).intValue();
+    }
+
+    /**
+     * Count attachments returned by a given query
+     *
+     * @param whereSql everything which would follow the "WHERE" in HQL
+     * @return int number of attachments found.
+     * @throws XWikiException
+     * @see #searchAttachments(String)
+     */
+    public int countAttachments(String whereSql)
+        throws XWikiException
+    {
+        return countAttachments(whereSql, null);
+    }
+
+    /**
      * Function to wrap a list of XWikiDocument into Document objects
      * 
      * @param docs list of XWikiDocument