From a4128725f5a2c6cbf3e963e2b78ba9382732728a Mon Sep 17 00:00:00 2001 From: Prem Sichanugrist Date: Mon, 4 May 2015 16:11:15 -0400 Subject: Add reversible syntax for change_column_default Passing `:from` and `:to` to `change_column_default` makes this command reversible as user has defined its previous state. So, instead of having the migration command as: change_column_default(:posts, :state, "draft") They can write it as: change_column_default(:posts, :state, from: nil, to: "draft") --- .../connection_adapters/abstract/schema_definitions.rb | 5 +++-- .../connection_adapters/abstract/schema_statements.rb | 15 ++++++++++++++- .../connection_adapters/abstract_mysql_adapter.rb | 3 ++- .../connection_adapters/postgresql/schema_statements.rb | 3 ++- .../active_record/connection_adapters/sqlite3_adapter.rb | 4 +++- .../lib/active_record/migration/command_recorder.rb | 12 +++++++++++- 6 files changed, 35 insertions(+), 7 deletions(-) (limited to 'activerecord/lib') diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb index 158b773e11..d17e272ed1 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb @@ -592,10 +592,11 @@ module ActiveRecord # # t.change_default(:qualification, 'new') # t.change_default(:authorized, 1) + # t.change_default(:status, from: nil, to: "draft") # # See SchemaStatements#change_column_default - def change_default(column_name, default) - @base.change_column_default(name, column_name, default) + def change_default(column_name, default_or_changes) + @base.change_column_default(name, column_name, default_or_changes) end # Removes the column(s) from the table definition. diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb index 49ffd7ccf0..8bbd96e722 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -460,7 +460,12 @@ module ActiveRecord # # change_column_default(:users, :email, nil) # - def change_column_default(table_name, column_name, default) + # Passing a hash containing +:from+ and +:to+ will make this change + # reversible in migration: + # + # change_column_default(:posts, :state, from: nil, to: "draft") + # + def change_column_default(table_name, column_name, default_or_changes) raise NotImplementedError, "change_column_default is not implemented" end @@ -1068,6 +1073,14 @@ module ActiveRecord raise ArgumentError, "Index name '#{new_name}' on table '#{table_name}' is too long; the limit is #{allowed_index_name_length} characters" end end + + def extract_new_default_value(default_or_changes) + if default_or_changes.is_a?(Hash) && default_or_changes.has_key?(:from) && default_or_changes.has_key?(:to) + default_or_changes[:to] + else + default_or_changes + end + end end end end diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb index 00e3d2965b..2027492f29 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb @@ -629,7 +629,8 @@ module ActiveRecord end end - def change_column_default(table_name, column_name, default) #:nodoc: + def change_column_default(table_name, column_name, default_or_changes) #:nodoc: + default = extract_new_default_value(default_or_changes) column = column_for(table_name, column_name) change_column table_name, column_name, column.sql_type, :default => default end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb index 595c635fc0..d114cad16b 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb @@ -410,11 +410,12 @@ module ActiveRecord end # Changes the default value of a table column. - def change_column_default(table_name, column_name, default) # :nodoc: + def change_column_default(table_name, column_name, default_or_changes) # :nodoc: clear_cache! column = column_for(table_name, column_name) return unless column + default = extract_new_default_value(default_or_changes) alter_column_query = "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} %s" if default.nil? # DEFAULT NULL results in the same behavior as DROP DEFAULT. However, PostgreSQL will diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb index 87129c42cf..7c809b088c 100644 --- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb @@ -422,7 +422,9 @@ module ActiveRecord end end - def change_column_default(table_name, column_name, default) #:nodoc: + def change_column_default(table_name, column_name, default_or_changes) #:nodoc: + default = extract_new_default_value(default_or_changes) + alter_table(table_name) do |definition| definition[column_name].default = default end diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb index b592c004aa..dcc2362397 100644 --- a/activerecord/lib/active_record/migration/command_recorder.rb +++ b/activerecord/lib/active_record/migration/command_recorder.rb @@ -72,7 +72,7 @@ module ActiveRecord [:create_table, :create_join_table, :rename_table, :add_column, :remove_column, :rename_index, :rename_column, :add_index, :remove_index, :add_timestamps, :remove_timestamps, - :change_column_default, :add_reference, :remove_reference, :transaction, + :add_reference, :remove_reference, :transaction, :drop_join_table, :drop_table, :execute_block, :enable_extension, :change_column, :execute, :remove_columns, :change_column_null, :add_foreign_key, :remove_foreign_key @@ -166,6 +166,16 @@ module ActiveRecord alias :invert_add_belongs_to :invert_add_reference alias :invert_remove_belongs_to :invert_remove_reference + def invert_change_column_default(args) + table, column, options = *args + + unless options && options.is_a?(Hash) && options.has_key?(:from) && options.has_key?(:to) + raise ActiveRecord::IrreversibleMigration, "change_column_default is only reversible if given a :from and :to option." + end + + [:change_column_default, [table, column, from: options[:to], to: options[:from]]] + end + def invert_change_column_null(args) args[2] = !args[2] [:change_column_null, args] -- cgit v1.2.3