Bug 164764 Joint data set does not work properly using attached flatfile
The data set preview keep empty in joint data set. Step to reproduce: 1.Create two data sets based on attached flat file 2.Make an inner join using joint data set with key "A". 3.Preview data set in data set editor. Expect result: The data set preview correctly Actual result: The data set preview is empty.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
Boolean bool = (Boolean) obj1;
					if ( bool.equals( Boolean.TRUE ) )
						return 1;
					else
						return -1;
				}
				else if ( obj1 instanceof Comparable )
				{
					if ( obj1 instanceof String )
					{
						return myCollator.compare( obj1, obj2 );
					}
					else
					{
						return ( (Comparable) obj1 ).compareTo( obj2 );
					}
				}
				
				else
				{
					return myCollator.compare( obj1.toString( ), obj2.toString( ) );
				}
			}
			else if ( MiscUtil.isNumericOrString( obj1 ) && MiscUtil.isNumericOrString( obj2 ) )
			{
				return DataTypeUtil.toDouble( obj1 ).compareTo(
						DataTypeUtil.toDouble( obj2 ) );
			}
			else if ( MiscUtil.isDateOrString( obj1 ) && MiscUtil.isDateOrString( obj2 ) )