More support for ALTER TABLE operations

[svoynow]

i.e. the ability to change the datatype of a row
ALTER TABLE mytable ALTER somecolumn TYPE uuid
Just a matter of adding some methods to ColumnOperations

I'll probably do it and send a PR at some point.

[hsgubert]

@svoynow-lz , do you know if Cassandra is currently supporting this operation?

I ask you because I remember some incongruencies between Cassandra docs and what is really implemented, so you really have to test the operation to see if it works.

[svoynow]

I believe it supports it in the case(s) where the data types are compatible / convertible.
So perhaps that would not be all that useful.
On further reflection, what would be useful would be being able to add table properties either in the create table operation and/or as a separate operation.

[hsgubert]

Right. So it is useful! I also agree with you second thought...

[juanlizarazo]

What about renaming column?

I was checking lib/cassandra_migrations/migration/column_operations.rb and rename_column isn't defined.

[juanlizarazo]

Never mind, just realized this would only work for primary_key names (which is the main purpose of RENAME in CQL) and it would return the "cannot rename non PRIMARY KEY part ...)" QueryError when used with non primary key column keys. That explains why it probably hasn't been implemented.