add index to the DataFrame

[feiyu-london]

Sometimes I would need to assign an index to both existing dataframe and new dataframe (most likely 1:n series), so that these two dataframes can be joined together.

Also the existing dataframe might be updated through operations, so a new index might be required so that the updated dataframe can be properly searched and referenced.

In both cases, being able to add a new index (e.g. a series of 1:n) conveniently can be good.

The solution can be found in SQL operation - alter table [dataframe] add new column and as#t auto_increment.

Hope this makes sense.

Regards,

Fei from the U.K.