Rails 6 has added support for bulk inserts similar to how bulk update issupported using update_all and bulk delete is supported using delete_all.Bulk inserts can be performed using newly added methods: insert_all,insert_all! and upsert_all.
All of these new methods allow the insertion of multiple records of the samemodel into the database. A single INSERT SQL query is prepared by thesemethods and a single sql statement is sent to the database, withoutinstantiating the model or invoking Active Record callbacks or validations.
During bulk insertion, violation of primary key, violation of unique indexes,and violation of unique constraints is possible. Rails leveragesdatabase-specific features to either skip, or upsert the duplicates, dependingon the case.
Let's discuss insert_all, insert_all! and upsert_all methods in detail,which are all used to perform bulk insert.
We will create an articles table with two unique indexes.
create_table :articles do |t| t.string :title, null: false t.string :slug, null: false t.string :author, null: false t.text :description t.index :slug, unique: true t.index [:title, :author], unique: trueend
Note that we do not allow duplicate slug columns. We also prevent records fromhaving duplicate title and author columns together.
To try out the examples provided in this blog post, please ensure to alwaysclean up the articles table before running any example.
1. Performing bulk inserts by skipping duplicates
Let's say we want to insert multiple articles at once into the database. It ispossible that certain records may violate the unique constraint(s) of the table.Such records are considered duplicates.
In other words, rows or records are determined to be unique by every uniqueindex on the table by default.
To skip the duplicate rows or records, and insert the rest of the records atonce, we can use ActiveRecord::Persistence#insert_all method.
1.1 Behavior with PostgreSQL
Let's run the following example on a PostgreSQL database.
result = Article.insert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, # duplicate 'id' here title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, { id: 2, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-1' }, { id: 3, title: 'Authentication with Devise - Part 1', author: 'Laura', # duplicate 'title' & 'author' here slug: 'devise-auth-2' }, { id: 4, title: 'Dockerizing and Deploying Rails App to Kubernetes', author: 'Paul', slug: 'rails-on-k8s' }, { id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, # duplicate 'slug' here { id: 6, title: 'Working Remotely', author: 'Greg', slug: 'working-remotely' } ])# Bulk Insert (2.3ms) INSERT INTO "articles"("id","title","author","slug") VALUES (1, 'Handling 1M Requests [...snip...] 'working-remotely') ON CONFLICT DO NOTHING RETURNING "id"puts result.inspect#<ActiveRecord::Result:0x00007fb6612a1ad8 @columns=["id"], @rows=[[1], [2], [4], [6]], @hash_rows=nil, @column_types={"id"=>#<ActiveModel::Type::Integer:0x00007fb65f420078 @precision=nil, @scale=nil, @limit=8, @range=-9223372036854775808...9223372036854775808>}>puts Article.count# 4
The insert_all method accepts a mandatory argument which should be an array ofhashes with the attributes of the same model. The keys in all hashes should besame.
Notice the ON CONFLICT DO NOTHING clause in the INSERT query. This clause issupported by PostgreSQL and SQLite databases. This instructs the database thatwhen there is a conflict or a unique key constraint violation during bulk insertoperation, to skip the conflicting record silently and proceed with theinsertion of the next record.
In the above example, we have exactly 3 records which violate various uniqueconstraints defined on the articles table.
One of the records being inserted has a duplicate id: 1 attribute, whichviolates unique primary key constraint. Another record that has duplicatetitle: 'Authentication with Devise - Part 1', author: 'Laura' attributesviolates the multi-column unique index defined on title and author columns.Another record has duplicate slug: '1m-req-per-second' attributes violates theunique index defined on the slug column.
All of these records that violate any unique constraint or unique index areskipped and are not inserted into the database.
If successful, ActiveRecord::Persistence#insert_all returns an instance ofActiveRecord::Result. The contents of the result vary per database. In case ofPostgreSQL database, this result instance holds information about thesuccessfully inserted records such as the chosen column names, values of thethose columns in each successfully inserted row, etc.
For PostgreSQL, by default, insert_all method appends RETURNING "id" clauseto the SQL query where id is the primary key(s). This clause instructs thedatabase to return the id of every successfully inserted record. By inspectingthe result, especially the @columns=["id"], @rows=[[1], [2], [4], [6]]attributes of the result instance, we can see that the records having idattribute with values 1, 2, 4 and 6 were successfully inserted.
What if we want to see more attributes and not just the id attribute of thesuccessfully inserted records in the result?
We should use the optional returning option, which accepts an array ofattribute names, which should be returned for all successfully inserted records!
result = Article.insert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, #...snip... ], returning: %w[ id title ])# Bulk Insert (2.3ms) INSERT INTO "articles"("id","title","author","slug") VALUES (1, 'Handling 1M Requests [...snip...] 'working-remotely') ON CONFLICT DO NOTHING RETURNING "id","title"puts result.inspect#<ActiveRecord::Result:0x00007f902a1196f0 @columns=["id", "title"], @rows=[[1, "Handling 1M Requests Per Second"], [2, "Authentication with Devise - Part 1"], [4, "Dockerizing and Deploying Rails App to Kubernetes"], [6, "Working Remotely"]], @hash_rows=nil, @column_types={"id"=>#<ActiveModel::Type::Integer:0x00007f90290ca8d0 @precision=nil, @scale=nil, @limit=8, @range=-9223372036854775808...9223372036854775808>, "title"=>#<ActiveModel::Type::String:0x00007f9029978298 @precision=nil, @scale=nil, @limit=nil>}>puts result.pluck("id", "title").inspect#[[1, "Handling 1M Requests Per Second"], [2, "Authentication with Devise - Part 1"], [4, "Dockerizing and Deploying Rails App to Kubernetes"], [6, "Working Remotely"]]
Notice how the INSERT query appends RETURNING "id","title" clause and theresult now holds the id and title attributes of the successfully insertedrecords.
1.2 Behavior with SQLite
Similar to PostgreSQL, the violating records are skipped during the bulk insertoperation performed using insert_all when we run our example on a SQLitedatabase.
result = Article.insert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here #...snip... ])# Bulk Insert (1.6ms) INSERT INTO "articles"("id","title","author","slug") VALUES (1, 'Handling 1M Requests [...snip...] 'working-remotely') ON CONFLICT DO NOTHINGputs result.inspect#<ActiveRecord::Result:0x00007fa9df448ff0 @columns=[], @rows=[], @hash_rows=nil, @column_types={}>puts Article.pluck(:id, :title)#[[1, "Handling 1M Requests Per Second"], [2, "Authentication with Devise - Part 1"], [4, "Dockerizing and Deploying Rails App to Kubernetes"], [6, "Working Remotely"]]puts Article.count# 4
Note that since SQLite does not support RETURING clause, it is not being addedto the SQL query. Therefore, the returned ActiveRecord::Result instance doesnot contain any useful information.
If we try to explicitly use the returning option when the database being usedis SQLite, then the insert_all method throws an error.
Article.insert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, #...snip... ], returning: %w[ id title ])# ActiveRecord::ConnectionAdapters::SQLite3Adapter does not support :returning (ArgumentError)
1.3 Behavior with MySQL
The records that violate primary key, unique key constraints, or unique indexesare skipped during bulk insert operation performed using insert_all on a MySQLdatabase.
result = Article.insert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here #...snip... ])# Bulk Insert (20.3ms) INSERT INTO `articles`(`id`,`title`,`author`,`slug`) VALUES (1, 'Handling 1M Requests [...snip...] 'working-remotely') ON DUPLICATE KEY UPDATE `id`=`id`puts result.inspect#<ActiveRecord::Result:0x000055d6cfea7580 @columns=[], @rows=[], @hash_rows=nil, @column_types={}>puts Article.pluck(:id, :title)#[[1, "Handling 1M Requests Per Second"], [2, "Authentication with Devise - Part 1"], [4, "Dockerizing and Deploying Rails App to Kubernetes"], [6, "Working Remotely"]]puts Article.count# 4
Here, the ON DUPLICATE KEY UPDATE 'id'='id' clause in the INSERT query isessentially doing the same thing as the ON CONFLICT DO NOTHING clausesupported by PostgreSQL and SQLite.
Since MySQL does not support RETURING clause, it is not being included in theSQL query and therefore, the result doesn't contain any useful information.
Explicitly trying to use returning option with insert_all method on a MySQLdatabase throwsActiveRecord::ConnectionAdapters::Mysql2Adapter does not support :returningerror.
2. Performing bulk inserts by skipping duplicates on a specified unique constraint but raising exception if records violate other unique constraints
In the previous case, we were skipping the records that were violating anyunique constraints. In some case, we may want to skip duplicates caused by onlya specific unique index but abort transaction if the other records violate anyother unique constraints.
The optional unique_by option of the insert_all method allows to define sucha unique constraint.
2.1 Behavior with PostgreSQL and SQLite
Let's see an example to skip duplicate records that violate only the specifiedunique index :index_articles_on_title_and_author using unique_by option. Theduplicate records that do not violate index_articles_on_title_and_author indexare not skipped, and therefore throw an error.
result = Article.insert_all( [ { .... }, { .... }, # duplicate 'id' here { .... }, { .... }, # duplicate 'title' and 'author' here { .... }, { .... }, # duplicate 'slug' here { .... } ], unique_by: :index_articles_on_title_and_author)# PG::UniqueViolation: ERROR: duplicate key value violates unique constraint "articles_pkey" (ActiveRecord::RecordNotUnique)# DETAIL: Key (id)=(1) already exists.
In case of SQLite, the error appears as shown below.
# SQLite3::ConstraintException: UNIQUE constraint failed: articles.id (ActiveRecord::RecordNotUnique)
In this case we get ActiveRecord::RecordNotUnique error which is caused by theviolation of primary key constraint on the id column.
It didn't skip the second record in the example above which violated the uniqueindex on primary key id since the unique_by option was specified with adifferent unique index.
When an exception occurs, no record persists to the database since insert_allexecutes just a single SQL query.
The unique_by option can be identified by columns or a unique index name.
~~~ruby unique_by: :index_articles_on_title_and_author
is same as
unique_by: %i[ title author ]
Also,
unique_by: :slug
is same as
unique_by: %i[ :slug ]
and also same as
unique_by: :index_articles_on_slug
Let's remove (or fix) the record that has duplicate primary keyandre-run the above example.~~~rubyresult = Article.insert_all( [ { .... }, { .... }, { .... }, { .... }, # duplicate 'title' and 'author' here { .... }, { .... }, # duplicate 'slug' here { .... } ], unique_by: :index_articles_on_title_and_author)# PG::UniqueViolation: ERROR: duplicate key value violates unique constraint "index_articles_on_slug" (ActiveRecord::RecordNotUnique)# DETAIL: Key (slug)=(1m-req-per-second) already exists.
In case of SQLite, the error looks appears as shown below.
# SQLite3::ConstraintException: UNIQUE constraint failed: articles.slug (ActiveRecord::RecordNotUnique)
The ActiveRecord::RecordNotUnique error in the example above now says theindex_articles_on_slug unique constraint is violated. Note how itintentionally didn't raise an error for the unique constraint violated on thetitle and author columns by the fourth record in the examples above.
Now we will remove (or fix) the record that has same slug.
result = Article.insert_all( [ { .... }, { .... }, { .... }, { .... }, # duplicate 'title' and 'author' here { .... }, { .... }, { .... } ], unique_by: :index_articles_on_title_and_author)# Bulk Insert (2.5ms) INSERT INTO "articles"("id","title","author","slug") VALUES (1, 'Handling 1M Requests Per Second', [...snip...] 'working-remotely') ON CONFLICT ("title","author") DO NOTHING RETURNING "id"puts result.inspect#<ActiveRecord::Result:0x00007fada2069828 @columns=["id"], @rows=[[1], [7], [2], [4], [5], [6]], @hash_rows=nil, @column_types={"id"=>#<ActiveModel::Type::Integer:0x00007fad9fdb9df0 @precision=nil, @scale=nil, @limit=8, @range=-9223372036854775808...9223372036854775808>}>
Here, the fourth record was skipped since that record violates the unique indexindex_articles_on_title_and_author specified by the unique_by option.
Similarly, we can specify a different unique index using the unique_by option.For example, if we specify unique_by: :slug option then the records containingduplicate slug columns will be skipped, but would raiseActiveRecord::RecordNotUnique exception if any record violates other uniqueconstraints.
2.2 Behavior with MySQL
The unique_by option is not supported when the database is MySQL.
3. Raising exception if any of the records being bulk inserted violate any unique constraints
The insert_all! method (with bang version) never skips a duplicate record. Ifa record violates any unique constraints, then insert_all! method would simplythrow an ActiveRecord::RecordNotUnique error.
When database is PostgreSQL, insert_all! method can accept optionalreturning option, which we discussed in depth in 1.1 section above.
The unique_by option is not supported by the insert_all! method.
4. Performing bulk upserts (updates or inserts)
So far, in the sections 1, 2 and 3 above, we discussed either skipping theduplicates or raising an exception if a duplicate is encountered during bulkinserts. Sometimes, we want to update the existing record when a duplicateoccurs otherwise insert a new record. This operation is called upsert becauseeither it tries to update the record, or if there is no record to update, thenit tries to insert.
The upsert_all method in Rails 6 allows performing bulk upserts.
Let's see it's usage and behavior with different database systems.
4.1 upsert_all in MySQL
Let's try to bulk upsert multiple articles containing some duplicates.
result = Article.upsert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, .... }, # duplicate 'id' here { id: 2, .... }, { id: 3, .... }, # duplicate 'title' and 'author' here { id: 4, .... }, { id: 5, .... }, # duplicate 'slug' here { id: 6, .... } ])# Bulk Insert (26.3ms) INSERT INTO `articles`(`id`,`title`,`author`,`slug`) VALUES (1, 'Handling 1M Requests Per Second', 'John', [...snip...] 'working-remotely') ON DUPLICATE KEY UPDATE `title`=VALUES(`title`),`author`=VALUES(`author`),`slug`=VALUES(`slug`)puts result.inspect#<ActiveRecord::Result:0x000055a43c1fae10 @columns=[], @rows=[], @hash_rows=nil, @column_types={}>puts Article.count# 5puts Article.all#<ActiveRecord::Relation [#<Article id: 1, title: "Type Safety in Elm", slug: "elm-type-safety", author: "George", description: nil>, #<Article id: 2, title: "Authentication with Devise - Part 1", slug: "devise-auth-2", author: "Laura", description: nil>, #<Article id: 4, title: "Dockerizing and Deploying Rails App to Kubernetes", slug: "rails-on-k8s", author: "Paul", description: nil>, #<Article id: 5, title: "Elm on Rails", slug: "1m-req-per-second", author: "Amanda", description: nil>, #<Article id: 6, title: "Working Remotely", slug: "working-remotely", author: "Greg", description: nil>]>
The persisted records in the database look exactly as intended. Let's discuss itin detail.
The second row in the input array that has the id: 1 attribute replaced thefirst row, which also had the duplicate id: 1 attribute.
The fourth row that has id: 3 replaced the attributes of the third row sinceboth had duplicate "title" and "author" attributes.
The rest of the rows were not duplicates or no longer became duplicates, andtherefore were inserted without any issues.
Note that the returning and unique_by options are not supported in theupsert_all method when the database is MySQL.
4.2 upsert_all in SQLite
Let's try to execute the same example from the above section 4.1 when databaseis SQLite.
result = Article.upsert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here { id: 2, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-1' }, { id: 3, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-2' }, # duplicate 'title' and 'author' here { id: 4, title: 'Dockerizing and Deploying Rails App to Kubernetes', author: 'Paul', slug: 'rails-on-k8s' }, { id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, # duplicate 'slug' here { id: 6, title: 'Working Remotely', author: 'Greg', slug: 'working-remotely' } ])# Bulk Insert (4.0ms) INSERT INTO "articles"("id","title","author","slug") VALUES (1, 'Handling 1M Requests Per Second', [...snip...] 'working-remotely') ON CONFLICT ("id") DO UPDATE SET "title"=excluded."title","author"=excluded."author","slug"=excluded."slug"# SQLite3::ConstraintException: UNIQUE constraint failed: articles.title, articles.author (ActiveRecord::RecordNotUnique)
The bulk upsert operation failed in the above example due toActiveRecord::RecordNotUnique exception.
Why it didn't work similar to MySQL?
As per the documentation of MySQL, an upsert operation takes place if a newrecord violates any unique constraint.
Whereas, in case of SQLite, by default, new record replaces existing record whenboth the existing and new record have the same primary key. If a record violatesany other unique constraints other than the primary key, it then raisesActiveRecord::RecordNotUnique exception.
The ON CONFLICT ("id") DO UPDATE clause in the SQL query above conveys thesame intent.
Therefore, upsert_all in SQLite doesn't behave exactly same as in MySQL.
As a workaround, we will need to upsert records with the help of multipleupsert_all calls with the usage of unique_by option.
If a duplicate record is encountered during the upsert operation, which violatesthe unique index specified using unique_by option then it will replace theattributes of the existing matching record.
Let's try to understand this workaround with another example.
Article.upsert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here ], unique_by: :id)Article.upsert_all( [ { id: 2, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-1' }, { id: 3, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-2' }, # duplicate 'title' and 'author' here { id: 4, title: 'Dockerizing and Deploying Rails App to Kubernetes', author: 'Paul', slug: 'rails-on-k8s' }, { id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, # duplicate 'slug' here { id: 6, title: 'Working Remotely', author: 'Greg', slug: 'working-remotely' } ], unique_by: %i[ title author ])puts Article.count# 5puts Article.all#<ActiveRecord::Relation [#<Article id: 1, title: "Type Safety in Elm", slug: "elm-type-safety", author: "George", description: nil>, #<Article id: 2, title: "Authentication with Devise - Part 1", slug: "devise-auth-2", author: "Laura", description: nil>, #<Article id: 4, title: "Dockerizing and Deploying Rails App to Kubernetes", slug: "rails-on-k8s", author: "Paul", description: nil>, #<Article id: 5, title: "Elm on Rails", slug: "1m-req-per-second", author: "Amanda", description: nil>, #<Article id: 6, title: "Working Remotely", slug: "working-remotely", author: "Greg", description: nil>]>
Here, we first tried to upsert all the records which violated the unique primarykey index on id column. Later, we upsert successfully all the remainingrecords, which violated the unique index on the title and author columns.
Note that since the first record's slug attribute was already replaced withthe second record's slug attribute; the last second record having id: 5didn't raise an exception because of duplicate slug column.
4.3 upsert_all in PostgreSQL
We will run the same example in the 4.1 section above with PostgreSQL database.
result = Article.upsert_all( [ { id: 1, title: 'Handling 1M Requests Per Second', author: 'John', slug: '1m-req-per-second' }, { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here { id: 2, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-1' }, { id: 3, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-2' }, # duplicate 'title' and 'author' here { id: 4, title: 'Dockerizing and Deploying Rails App to Kubernetes', author: 'Paul', slug: 'rails-on-k8s' }, { id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, # duplicate 'slug' here { id: 6, title: 'Working Remotely', author: 'Greg', slug: 'working-remotely' } ])# PG::CardinalityViolation: ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time (ActiveRecord::StatementInvalid)# HINT: Ensure that no rows proposed for insertion within the same command have duplicate constrained values.
The bulk upsert operation failed in the above example due toActiveRecord::StatementInvalid exception which was caused by anotherPG::CardinalityViolation exception.
The PG::CardinalityViolation exception originates fromhere.
The PG::CardinalityViolation exception occurs when a row cannot be updated asecond time in the same ON CONFLICT DO UPDATE SQL query. PostgreSQL assumesthis behavior would lead the same row to updated a second time in the same SQLquery, in unspecified order, non-deterministically.
PostgreSQL recommends it is the developer's responsibility to prevent thissituation from occurring.
Here's more discussion about this issue -rails/rails#35519.
Therefore, the upsert_all method doesn't work as intended due to the abovelimitation in PostgreSQL.
As a workaround, we can divide the single upsert_all query into multipleupsert_all queries with the use of unique_by option similar to how we did incase of SQLite in the 4.2 section above.
Article.insert_all( [ { id: 1, title: 'Handling 1M requests per second', author: 'John', slug: '1m-req-per-second' }, { id: 2, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-1' }, { id: 4, title: 'Dockerizing and deploy Rails app to Kubernetes', author: 'Paul', slug: 'rails-on-k8s' }, { id: 6, title: 'Working Remotely', author: 'Greg', slug: 'working-remotely' } ])Article.upsert_all( [ { id: 1, title: 'Type Safety in Elm', author: 'George', slug: 'elm-type-safety' }, # duplicate 'id' here ])Article.upsert_all( [ { id: 3, title: 'Authentication with Devise - Part 1', author: 'Laura', slug: 'devise-auth-2' }, # duplicate 'title' and 'author' here ], unique_by: :index_articles_on_title_and_author)Article.upsert_all( [ { id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, # duplicate 'slug' here ])puts Article.count# 5puts Article.all#<ActiveRecord::Relation [#<Article id: 1, title: "Type Safety in Elm", slug: "elm-type-safety", author: "George", description: nil>, #<Article id: 2, title: "Authentication with Devise - Part 1", slug: "devise-auth-2", author: "Laura", description: nil>, #<Article id: 4, title: "Dockerizing and deploy Rails app to Kubernetes", slug: "rails-on-k8s", author: "Paul", description: nil>, #<Article id: 5, title: "Elm on Rails", slug: "1m-req-per-second", author: "Amanda", description: nil>, #<Article id: 6, title: "Working Remotely", slug: "working-remotely", author: "Greg", description: nil>]>
For reference, note that the upsert_all method also accepts returning optionfor PostgreSQL which we have already discussed in the 1.1 section above.
5. insert, insert! and upsert
Rails 6 has also introduced three more additional methods namely insert,insert! and upsert for convenience.
The insert method inserts a single record into the database. If that recordviolates a uniqueness constrain, then the insert method will skip insertingrecord into the database without raising an exception.
Similarly, the insert! method also inserts a single record into the database,but will raise ActiveRecord::RecordNotUnique exception if that record violatesa uniqueness constraint.
The upsert method inserts or updates a single record into the database similarto how upsert_all does.
The methods insert, insert! and upsert are wrappers around insert_all,insert_all! and upsert_all respectively.
Let's see some examples to understand the usage of these methods.
Article.insert({ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, unique_by: :slug)# is same asArticle.insert_all([{ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }], unique_by: :slug)
Article.insert!({ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, returning: %w[ id title ])# is same asArticle.insert_all!([{ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }], returning: %w[ id title ])
Article.upsert({ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }, unique_by: :slug, returning: %w[ id title ])# is same asArticle.upsert_all([{ id: 5, title: 'Elm on Rails', author: 'Amanda', slug: '1m-req-per-second' }], unique_by: :slug, returning: %w[ id title ])
To learn more about the bulk insert feature and its implementation, please checkrails/rails#35077,rails/rails#35546 andrails/rails#35854.
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