passing unique parameter to belongs_to wrongly

[0oneo]

passing unique parameter to belongs_to not right

Summary

the original code can't generate unique index:

create_table :accounts do |t|
  t.belongs_to :supplier, index: true, unique: true, foreign_key: true
  # ...
end

the generated schema.rb is:

create_table "accounts", force: :cascade do |t|
    t.string   "account_number"
    t.integer  "supplier_id"
    t.datetime "created_at",     null: false
    t.datetime "updated_at",     null: false
    t.index ["supplier_id"], name: "index_accounts_on_supplier_id"
 end

when change the migration code to:

create_table :accounts do |t|
      t.string :account_number
      t.belongs_to :supplier, index: { unique: true }, foreign_key: true

      t.timestamps
end

the result is right:

create_table "accounts", force: :cascade do |t|
    t.string   "account_number"
    t.integer  "supplier_id"
    t.datetime "created_at",     null: false
    t.datetime "updated_at",     null: false
    t.index ["supplier_id"], name: "index_accounts_on_supplier_id", unique: true
end

[0oneo]

BTW, from the generated result, I don't quite get the meaning of foreign_key: true optional parameter

[sevenseacat]

It adds a database-level foreign key between the tables. After running the migration your schema.rb should have an add_foreign_key line at the bottom of it.

[0oneo]

@sevenseacat I have located the release notes of 4.2, it saids "only the mysql, mysql2 and postgresql adapters support foreign keys"

[sevenseacat]

that's correct.

[kamipo]

Thanks!

In the future, please add [ci skip] to any commits that involve changing the documentation, to avoid running the entire Rails test suite.