diff options
Diffstat (limited to 'guides/source')
| -rw-r--r-- | guides/source/active_record_migrations.md | 18 | ||||
| -rw-r--r-- | guides/source/active_support_core_extensions.md | 8 |
2 files changed, 14 insertions, 12 deletions
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md index a45becf670..d91c9bd606 100644 --- a/guides/source/active_record_migrations.md +++ b/guides/source/active_record_migrations.md @@ -467,6 +467,8 @@ the first time (i.e. on the date the migration is applied). Some adapters may support additional options; see the adapter specific API docs for further information. +NOTE: `null` and `default` cannot be specified via command line. + ### Foreign Keys While it's not required you might want to add foreign key constraints to @@ -1018,10 +1020,10 @@ such features, the `execute` method can be used to execute arbitrary SQL. Migrations and Seed Data ------------------------ -The main purpose of Rails' migration feature is to issue commands that modify the -schema using a consistent process. Migrations can also be used -to add or modify data. This is useful in an existing database that can't be destroyed -and recreated, such as a production database. +The main purpose of Rails' migration feature is to issue commands that modify the +schema using a consistent process. Migrations can also be used +to add or modify data. This is useful in an existing database that can't be destroyed +and recreated, such as a production database. ```ruby class AddInitialProducts < ActiveRecord::Migration[5.0] @@ -1037,10 +1039,10 @@ class AddInitialProducts < ActiveRecord::Migration[5.0] end ``` -To add initial data after a database is created, Rails has a built-in -'seeds' feature that makes the process quick and easy. This is especially -useful when reloading the database frequently in development and test environments. -It's easy to get started with this feature: just fill up `db/seeds.rb` with some +To add initial data after a database is created, Rails has a built-in +'seeds' feature that makes the process quick and easy. This is especially +useful when reloading the database frequently in development and test environments. +It's easy to get started with this feature: just fill up `db/seeds.rb` with some Ruby code, and run `rails db:seed`: ```ruby diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md index 60a6c37f82..70b04a9695 100644 --- a/guides/source/active_support_core_extensions.md +++ b/guides/source/active_support_core_extensions.md @@ -2661,7 +2661,7 @@ The method `transform_keys` accepts a block and returns a hash that has applied ```ruby {nil => nil, 1 => 1, a: :a}.transform_keys { |key| key.to_s.upcase } -# => {"" => nil, "A" => :a, "1" => 1} +# => {"" => nil, "1" => 1, "A" => :a} ``` In case of key collision, one of the values will be chosen. The chosen value may not always be the same given the same hash: @@ -2703,7 +2703,7 @@ The method `stringify_keys` returns a hash that has a stringified version of the ```ruby {nil => nil, 1 => 1, a: :a}.stringify_keys -# => {"" => nil, "a" => :a, "1" => 1} +# => {"" => nil, "1" => 1, "a" => :a} ``` In case of key collision, one of the values will be chosen. The chosen value may not always be the same given the same hash: @@ -2745,7 +2745,7 @@ The method `symbolize_keys` returns a hash that has a symbolized version of the ```ruby {nil => nil, 1 => 1, "a" => "a"}.symbolize_keys -# => {1=>1, nil=>nil, :a=>"a"} +# => {nil=>nil, 1=>1, :a=>"a"} ``` WARNING. Note in the previous example only one key was symbolized. @@ -2822,7 +2822,7 @@ Ruby has built-in support for taking slices out of strings and arrays. Active Su ```ruby {a: 1, b: 2, c: 3}.slice(:a, :c) -# => {:c=>3, :a=>1} +# => {:a=>1, :c=>3} {a: 1, b: 2, c: 3}.slice(:b, :X) # => {:b=>2} # non-existing keys are ignored |