please describe best way for getting ddl script on difference between 2 revision in VCS.
Now i use 2 working copy on my local machine with different revision and receive ddl script on difference after compare 2 model.
The question is not very clear to me: what you want to do - are these 2 working copies created by checking out one and the same svn repository location? (and respectively synchronized with one and the same project(design))
If you want to continue working on one and the same project (design), but want to separate your changes from the mainstream project (design) you probably should use branching.