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-rw-r--r-- | guides/source/active_record_migrations.md | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md index e2359a35f1..9446441b20 100644 --- a/guides/source/active_record_migrations.md +++ b/guides/source/active_record_migrations.md @@ -491,9 +491,8 @@ NOTE: Active Record only supports single column foreign keys. `execute` and `structure.sql` are required to use composite foreign keys. See [Schema Dumping and You](#schema-dumping-and-you). -NOTE: At this time, only the mysql, mysql2 and postgresql adapters support -foreign keys. Implementation for sqlite3 is partial, keys are created for new -tables but not for existing tables via `ALTER TABLE` statement. +NOTE: The SQLite3 adapter doesn't support `add_foreign_key` since SQLite supports +only [a limited subset of ALTER TABLE](https://www.sqlite.org/lang_altertable.html). Removing a foreign key is easy as well: |