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Diffstat (limited to 'doc/development/database/setting_multiple_values.md')
| -rw-r--r-- | doc/development/database/setting_multiple_values.md | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/doc/development/database/setting_multiple_values.md b/doc/development/database/setting_multiple_values.md index 5569a0e10b7..c354247a9f8 100644 --- a/doc/development/database/setting_multiple_values.md +++ b/doc/development/database/setting_multiple_values.md @@ -1,9 +1,15 @@ +--- +stage: Enablement +group: Database +info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers +--- + # Setting Multiple Values > [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/32921) in GitLab 13.5. -Frequently, we will want to update multiple objects with new values for one -or more columns. The obvious way to do this is using `Relation#update_all`: +There's often a need to update multiple objects with new values for one +or more columns. One method of doing this is using `Relation#update_all`: ```ruby user.issues.open.update_all(due_date: 7.days.from_now) # (1) @@ -28,11 +34,11 @@ update issues where id = obj_id ``` -The bad news: There is no way to express this in ActiveRecord or even dropping -down to ARel - the `UpdateManager` just does not support `update from`, so this +The bad news: there is no way to express this in ActiveRecord or even dropping +down to ARel. The `UpdateManager` does not support `update from`, so this is not expressible. -The good news: We supply an abstraction to help you generate these kinds of +The good news: we supply an abstraction to help you generate these kinds of updates, called `Gitlab::Database::BulkUpdate`. This constructs queries such as the above, and uses binding parameters to avoid SQL injection. @@ -44,7 +50,7 @@ To use this, we need: - a mapping from object/ID to the new values to set for that object - a way to determine the table for each object -So for example, we can express the query above as: +For example, we can express the query above as: ```ruby issue_a = Issue.find(..) @@ -87,7 +93,7 @@ objects = Foo.from_union([ ]) # At this point, all the objects are instances of Foo, even the ones from the # Bar table -mapping = objects.to_h { |obj| [obj, bazzes[obj.id] } +mapping = objects.to_h { |obj| [obj, bazzes[obj.id]] } # Issues at most 2 queries ::Gitlab::Database::BulkUpdate.execute(%i[baz], mapping) do |obj| @@ -100,4 +106,4 @@ end Note that this is a **very low level** tool, and operates on the raw column values. Enumerations and state fields must be translated into their underlying representations, for example, and nested associations are not supported. No -validations or hooks will be called. +validations or hooks are called. |