Bug 153387 Database item can't be dragged and dropped onto editor field
Steps to reproduce: 1.Start up BIRT in Mac OS X; 2.File->New->Project; 3.File->New->Report Design; 4.In Data Explorer, create a New Data Source, and choose "Classic Models Inc. Sample DataBase", press "Next" and then press "finish"; 5.In Data Explorer, create a New Data Set, press "Next"; 6.In the popup window, expand the "CLASSICMODELS", select and drag a item onto the editor field at right side.
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
DbObject.SCHEMA_TYPE,
								schemaImage );
						schemaObjectList.add( schemaObj );
						count++;
					}
				}
			}
			else
			{
				String schemaName = schemaCombo.getItem( schemaCombo.getSelectionIndex( ) );
				DbObject schemaObj = new DbObject( schemaName,
						schemaName,
						DbObject.SCHEMA_TYPE,
						schemaImage );
				schemaObjectList.add( schemaObj );
			}
			TreeItem[] items = Utility.createTreeItems( rootNode,
					schemaObjectList,
					SWT.NONE,
					schemaImage );
			if ( items != null && items.length > 0 )
			{
				availableDbObjectsTree.showItem( items[0] );
			}
		}
	}
	
	/**
	 * 
	 * @param schemaName