A method for altering the definitions of tables with data

[dimitri-yatsenko]

I propose to have a single alter method in dj.Relation. It will take the current definition and update the table definition.

This will require computing the difference between the current definition and the new definition and generating alter commands to update the definition.

Two methods:
preview_alter(self) -- shows the required changes
alter(self, data_loss_ok=False, preview_only=False) -- executes the changes

[fabiansinz]

Agreement from my side.

[dimitri-yatsenko]

This may be helpful: https://github.com/djrobstep/migra