Bug 416703 Mongodb : Display correctly the Number data type
data/org.eclipse.birt.data.oda.mongodb/src/org/eclipse/birt/data/oda/mongodb/impl/MDbResultSet.java
logFetchedFirstElementFromArray( columnName, valuesList.size() );
        return firstValue;
    }
    private static Object tryConvertToDataType( Object value, Class<?> valueDataType ) throws OdaException
    {
        if( value == null || valueDataType.isInstance( value ) ) 
            return value;
        
        if( value instanceof String )
        {
            String stringValue = (String)value;
            try
            {
                if( valueDataType == Integer.class )
                    return Integer.valueOf( stringValue );
                if( valueDataType == Double.class )
                    return Double.valueOf( stringValue );
                if( valueDataType == BigDecimal.class )
                    return new BigDecimal( stringValue );
                if( valueDataType == Boolean.class ) 
                    return Boolean.valueOf( stringValue );
                if( valueDataType == Date.class ) 
                    return Date.valueOf( stringValue );
                if( valueDataType == Timestamp.class )
                    return Timestamp.valueOf( stringValue );
            }
            catch( NumberFormatException ex )
            {
                throw new OdaException( ex );
            }