Class: Cequel::Schema::TableDiffer

Inherits:
Object
  • Object
show all
Defined in:
lib/cequel/schema/table_differ.rb

Overview

Utility object that calculates a ‘Patch` to transform one `Table` into another.

Currently this support adding columns, adding and removing indexes, and setting properties on the table. Any other changes are prohibited due to CQL limitation or data integrity concerns. A ‘InvalidSchemaMigration` will be raised if unsupported changes are detected.

Since:

  • 1.0.0

Instance Method Summary collapse

Instance Method Details

#call ⇒ Object

Returns a Patch that will transform table_a in to table_b.

Since:

  • 1.0.0



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# File 'lib/cequel/schema/table_differ.rb', line 21

def call
  (fail InvalidSchemaMigration, "Table renames are not supported") if
    table_a.name != table_b.name
  (fail InvalidSchemaMigration, "Changes to key structure is not allowed") if
    keys_changed?
  (fail InvalidSchemaMigration, "Type changes are not allowed") if any_types_changed?

  Patch.new(figure_changes)
end