5 files changed, 25 insertions, 10 deletions
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index 4cf4111bf0..5c1de97aa8 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -309,12 +309,12 @@ user = User.find_by(name: 'David')
 user.destroy
 ```
 
-If you'd like to delete several records in bulk, you may use `destroy_all`
-method:
+If you'd like to delete several records in bulk, you may use `destroy_by`
+or `destroy_all` method:
 
 ```ruby
 # find and delete all users named David
-User.where(name: 'David').destroy_all
+User.destroy_by(name: 'David')
 
 # delete all users
 User.destroy_all
diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md
index ebdee446f9..614737c342 100644
--- a/guides/source/active_record_callbacks.md
+++ b/guides/source/active_record_callbacks.md
@@ -239,13 +239,12 @@ Skipping Callbacks
 
 Just as with validations, it is also possible to skip callbacks by using the following methods:
 
-* `decrement`
+* `decrement!`
 * `decrement_counter`
 * `delete`
 * `delete_all`
-* `increment`
+* `increment!`
 * `increment_counter`
-* `toggle`
 * `update_column`
 * `update_columns`
 * `update_all`
@@ -310,7 +309,7 @@ end
 
 ### Using `:if` and `:unless` with a `Proc`
 
-Finally, it is possible to associate `:if` and `:unless` with a `Proc` object. This option is best suited when writing short validation methods, usually one-liners:
+It is possible to associate `:if` and `:unless` with a `Proc` object. This option is best suited when writing short validation methods, usually one-liners:
 
 ```ruby
 class Order < ApplicationRecord
@@ -338,6 +337,20 @@ class Comment < ApplicationRecord
 end
 ```
 
+### Combining Callback Conditions
+
+When multiple conditions define whether or not a callback should happen, an `Array` can be used. Moreover, you can apply both `:if` and `:unless` to the same callback.
+
+```ruby
+class Comment < ApplicationRecord
+  after_create :send_email_to_author,
+    if: [Proc.new { |c| c.user.allow_send_email? }, :author_wants_emails?],
+    unless: Proc.new { |c| c.article.ignore_comments? }
+end
+```
+
+The callback only runs when all the `:if` conditions and none of the `:unless` conditions are evaluated to `true`.
+
 Callback Classes
 ----------------
 
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index fd1dcf22c0..cb738f0657 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -623,6 +623,8 @@ To select only a subset of fields from the result set, you can specify the subse
 For example, to select only `viewable_by` and `locked` columns:
 
 ```ruby
+Client.select(:viewable_by, :locked)
+# OR
 Client.select("viewable_by, locked")
 ```
 
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 0fda7c5cfd..0c57802188 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -934,7 +934,7 @@ end
 
 ### Using a Proc with `:if` and `:unless`
 
-Finally, it's possible to associate `:if` and `:unless` with a `Proc` object
+It is possible to associate `:if` and `:unless` with a `Proc` object
 which will be called. Using a `Proc` object gives you the ability to write an
 inline condition instead of a separate method. This option is best suited for
 one-liners.
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index be59cd0cfa..7ee0d8c916 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -683,7 +683,7 @@ If you look in the `db/migrate/YYYYMMDDHHMMSS_create_articles.rb` file
 (remember, yours will have a slightly different name), here's what you'll find:
 
 ```ruby
-class CreateArticles < ActiveRecord::Migration[5.0]
+class CreateArticles < ActiveRecord::Migration[6.0]
   def change
     create_table :articles do |t|
       t.string :title
@@ -1555,7 +1555,7 @@ In addition to the model, Rails has also made a migration to create the
 corresponding database table:
 
 ```ruby
-class CreateComments < ActiveRecord::Migration[5.0]
+class CreateComments < ActiveRecord::Migration[6.0]
   def change
     create_table :comments do |t|
       t.string :commenter