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| author | Bob Lail <bob.lailfamily@gmail.com> | 2019-03-08 08:04:53 -0600 |
|---|---|---|
| committer | Bob Lail <bob.lailfamily@gmail.com> | 2019-03-08 08:04:53 -0600 |
| commit | 02441e8f1726efaa69e2683702652ed343692b6c (patch) | |
| tree | ffc0a60fc982b7c22c19a0181d8b8cf1e486cf58 /activerecord | |
| parent | 199de6bee261dd816b68c841c7775fdcd02b68d2 (diff) | |
| download | rails-02441e8f1726efaa69e2683702652ed343692b6c.tar.gz rails-02441e8f1726efaa69e2683702652ed343692b6c.tar.bz2 rails-02441e8f1726efaa69e2683702652ed343692b6c.zip | |
Update documentation on upsert_all so that it is correct for Postgres
Details in https://github.com/rails/rails/issues/35519
In short, MySQL and Sqlite3 allow a record to be both inserted _and_ replaced in the same operation. Postgres (and the SQL-2003 rules for MERGE) do not.
Postgres's rationale seems to be that the operation would be nondeterministic.
I think it's OK for Rails users to have a different experience with this feature depending on their database; but I think you should be able to follow the examples in the docs on any database.
Diffstat (limited to 'activerecord')
| -rw-r--r-- | activerecord/lib/active_record/persistence.rb | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb index a09b5f0e96..200cfed465 100644 --- a/activerecord/lib/active_record/persistence.rb +++ b/activerecord/lib/active_record/persistence.rb @@ -240,11 +240,15 @@ module ActiveRecord # # ==== Examples # - # # Insert multiple records, performing an upsert when records have duplicate ISBNs + # # Given a Unique Index on books.isbn and the following record: + # Book.create!(title: 'Rework', author: 'David', isbn: '1') + # + # # Insert multiple records, allowing new records with the same ISBN + # # as an existing record to overwrite the existing record. # # ('Eloquent Ruby' will overwrite 'Rework' because its ISBN is duplicate) # Book.upsert_all([ - # { title: 'Rework', author: 'David', isbn: '1' }, - # { title: 'Eloquent Ruby', author: 'Russ', isbn: '1' } + # { title: 'Eloquent Ruby', author: 'Russ', isbn: '1' }, + # { title: 'Clean Code', author: 'Robert', isbn: '2' } # ], # unique_by: { columns: %w[ isbn ] }) # |