lib/lhm/migrator.rb in lhm-1.3.0 vs lib/lhm/migrator.rb in lhm-2.0.0

@@ -11,11 +11,11 @@
   # `run` returns a Migration which can be used for the remaining process.
   class Migrator
     include Command
     include SqlHelper
 
-    attr_reader :name, :statements, :connection
+    attr_reader :name, :statements, :connection, :conditions
 
     def initialize(table, connection = nil)
       @connection = connection
       @origin = table
       @name = table.destination_name
@@ -133,14 +133,33 @@
     #   A column name given as String or Symbol. An Array of Strings or Symbols
     #   for compound indexes.
     # @param [String, Symbol] index_name
     #   Optional name of the index to be removed
     def remove_index(columns, index_name = nil)
+      columns = [columns].flatten.map(&:to_sym)
+      from_origin = @origin.indices.find {|name, cols| cols.map(&:to_sym) == columns}
+      index_name ||= from_origin[0] unless from_origin.nil?
       index_name ||= idx_name(@origin.name, columns)
       ddl("drop index `%s` on `%s`" % [index_name, @name])
     end
 
+    # Filter the data that is copied into the new table by the provided SQL.
+    # This SQL will be inserted into the copy directly after the "from"
+    # statement - so be sure to use inner/outer join syntax and not cross joins.
+    #
+    # @example Add a conditions filter to the migration.
+    #   Lhm.change_table(:sounds) do |m|
+    #     m.filter("inner join users on users.`id` = sounds.`user_id` and sounds.`public` = 1")
+    #   end
+    #
+    # @param [ String ] sql The sql filter.
+    #
+    # @return [ String ] The sql filter.
+    def filter(sql)
+      @conditions = sql
+    end
+
   private
 
     def validate
       unless @connection.table_exists?(@origin.name)
         error("could not find origin table #{ @origin.name }")
@@ -158,10 +177,10 @@
     end
 
     def execute
       destination_create
       @connection.sql(@statements)
-      Migration.new(@origin, destination_read)
+      Migration.new(@origin, destination_read, conditions)
     end
 
     def destination_create
       @connection.destination_create(@origin)
     end