diff options
Diffstat (limited to 'guides/source/active_record_querying.md')
| -rw-r--r-- | guides/source/active_record_querying.md | 39 |
1 files changed, 11 insertions, 28 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 5e6799e786..76548a3397 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -1227,7 +1227,7 @@ Find or build a new object It's common that you need to find a record or create it if it doesn't exist. You can do that with the `find_or_create_by` and `find_or_create_by!` methods. -### `find_or_create_by` and `first_or_create` +### `find_or_create_by` The `find_or_create_by` method checks whether a record with the attributes exists. If it doesn't, then `create` is called. Let's see an example. @@ -1251,13 +1251,18 @@ COMMIT The new record might not be saved to the database; that depends on whether validations passed or not (just like `create`). -Suppose we want to set the 'locked' attribute to true, if we're +Suppose we want to set the 'locked' attribute to true if we're creating a new record, but we don't want to include it in the query. So we want to find the client named "Andy", or if that client doesn't exist, create a client named "Andy" which is not locked. -We can achive this in two ways. The first is passing a block to the -`find_or_create_by` method: +We can achive this in two ways. The first is to use `create_with`: + +```ruby +Client.create_with(locked: false).find_or_create_by(first_name: 'Andy') +``` + +The second way is using a block: ```ruby Client.find_or_create_by(first_name: 'Andy') do |c| @@ -1268,23 +1273,7 @@ end The block will only be executed if the client is being created. The second time we run this code, the block will be ignored. -The second way is using the `first_or_create` method: - -```ruby -Client.where(first_name: 'Andy').first_or_create(locked: false) -``` - -In this version, we are building a scope to search for Andy, and getting -the first record if it existed, or else creating it with `locked: -false`. - -Note that these two are slightly different. In the second version, the -scope that we build will affect any other queries that may happens while -creating the record. For example, if we had a callback that ran -another query, that would execute within the `Client.where(first_name: -'Andy')` scope. - -### `find_or_create_by!` and `first_or_create!` +### `find_or_create_by!` You can also use `find_or_create_by!` to raise an exception if the new record is invalid. Validations are not covered on this guide, but let's assume for a moment that you temporarily add @@ -1299,10 +1288,7 @@ Client.find_or_create_by!(first_name: 'Andy') # => ActiveRecord::RecordInvalid: Validation failed: Orders count can't be blank ``` -There is also a `first_or_create!` method which does a similar thing for -`first_or_create`. - -### `find_or_initialize_by` and `first_or_initialize` +### `find_or_initialize_by` The `find_or_initialize_by` method will work just like `find_or_create_by` but it will call `new` instead of `create`. This @@ -1334,9 +1320,6 @@ nick.save # => true ``` -There is also a `first_or_initialize` method which does a similar thing -for `first_or_create`. - Finding by SQL -------------- |