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Diffstat (limited to 'guides/source/active_record_querying.md')
-rw-r--r-- | guides/source/active_record_querying.md | 23 |
1 files changed, 3 insertions, 20 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index c9e265de08..35467fe95b 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -267,23 +267,6 @@ This is equivalent to writing: Client.where(first_name: 'does not exist').take! ``` -#### `last!` - -`Model.last!` finds the last record ordered by the primary key. For example: - -```ruby -client = Client.last! -# => #<Client id: 221, first_name: "Russel"> -``` - -The SQL equivalent of the above is: - -```sql -SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 -``` - -`Model.last!` raises `ActiveRecord::RecordNotFound` if no matching record is found. - ### Retrieving Multiple Objects in Batches We often need to iterate over a large set of records, as when we send a newsletter to a large set of users, or when we export data. @@ -293,7 +276,7 @@ This may appear straightforward: ```ruby # This is very inefficient when the users table has thousands of rows. User.all.each do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver end ``` @@ -333,7 +316,7 @@ The `:batch_size` option allows you to specify the number of records to be retri ```ruby User.find_each(batch_size: 5000) do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver end ``` @@ -345,7 +328,7 @@ For example, to send newsletters only to users with the primary key starting fro ```ruby User.find_each(start: 2000, batch_size: 5000) do |user| - NewsLetter.weekly_deliver(user) + NewsMailer.weekly(user).deliver end ``` |