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
Image image = tableImage;
							
					if ( tablesRs != null )
					{
						int numberOfTable;
						
						Preferences preferences = JdbcPlugin.getDefault( ).getPluginPreferences( );
						if ( preferences.contains( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA ) )
						{
							numberOfTable = preferences.getInt( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA );
						}
						else
						{
							numberOfTable = DateSetPreferencePage.DEFAULT_MAX_NUM_OF_TABLE_EACH_SCHEMA;
							preferences.setValue( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA,
									numberOfTable );
						}
						int count = 0;			
						
						while ( tablesRs.next( ) && count < numberOfTable)
						{