Bug 416703 Mongodb : Display correctly the Number data type
data/org.eclipse.birt.data.oda.mongodb/src/org/eclipse/birt/data/oda/mongodb/internal/impl/MDbMetaData.java
if( searchLimit <= 0 )  
            searchLimit = DEFAULT_META_DATA_SEARCH_LIMIT;
                        
        
        if( runtimeProps.hasValidCommandOperation() )
        {
            QueryModel.validateCommandSyntax( runtimeProps.getOperationType(), 
                                runtimeProps.getOperationExpression() );
            Iterable<DBObject> commandResults = null;
            if( runtimeProps.hasAggregateCommand() )
                commandResults = MDbOperation.callAggregateCmd( collection, runtimeProps );
            else if( runtimeProps.hasMapReduceCommand() )
            {
                MapReduceOutput mapReduceOut = MDbOperation.callMapReduceCmd( collection, runtimeProps );
                commandResults = mapReduceOut.results();
                
            }
            else if( runtimeProps.hasRunCommand() )
                commandResults = MDbOperation.callDBCommand( m_connectedDB, runtimeProps );
            
            if( commandResults != null )
                return getMetaData( commandResults, searchLimit );
            return sm_emptyFields;
        }
        
        DBCursor rowsCursor = collection.find();
        if( searchLimit > 0 )
            rowsCursor.limit( searchLimit );
        
        QueryProperties mdCursorProps = runtimeProps != null ?