require "active_record/migration/join_table"
require "active_support/core_ext/string/access"
require "digest"
module ActiveRecord
module ConnectionAdapters # :nodoc:
module SchemaStatements
include ActiveRecord::Migration::JoinTable
# Returns a hash of mappings from the abstract data types to the native
# database types. See TableDefinition#column for details on the recognized
# abstract data types.
def native_database_types
{}
end
def table_options(table_name)
nil
end
# Returns the table comment that's stored in database metadata.
def table_comment(table_name)
nil
end
# Truncates a table alias according to the limits of the current adapter.
def table_alias_for(table_name)
table_name[0...table_alias_length].tr(".", "_")
end
# Returns the relation names useable to back Active Record models.
# For most adapters this means all #tables and #views.
def data_sources
select_values(data_source_sql, "SCHEMA")
rescue NotImplementedError
tables | views
end
# Checks to see if the data source +name+ exists on the database.
#
# data_source_exists?(:ebooks)
#
def data_source_exists?(name)
select_values(data_source_sql(name), "SCHEMA").any? if name.present?
rescue NotImplementedError
data_sources.include?(name.to_s)
end
# Returns an array of table names defined in the database.
def tables
select_values(data_source_sql(type: "BASE TABLE"), "SCHEMA")
end
# Checks to see if the table +table_name+ exists on the database.
#
# table_exists?(:developers)
#
def table_exists?(table_name)
select_values(data_source_sql(table_name, type: "BASE TABLE"), "SCHEMA").any? if table_name.present?
rescue NotImplementedError
tables.include?(table_name.to_s)
end
# Returns an array of view names defined in the database.
def views
select_values(data_source_sql(type: "VIEW"), "SCHEMA")
end
# Checks to see if the view +view_name+ exists on the database.
#
# view_exists?(:ebooks)
#
def view_exists?(view_name)
select_values(data_source_sql(view_name, type: "VIEW"), "SCHEMA").any? if view_name.present?
rescue NotImplementedError
views.include?(view_name.to_s)
end
# Returns an array of indexes for the given table.
def indexes(table_name, name = nil)
raise NotImplementedError, "#indexes is not implemented"
end
# Checks to see if an index exists on a table for a given index definition.
#
# # Check an index exists
# index_exists?(:suppliers, :company_id)
#
# # Check an index on multiple columns exists
# index_exists?(:suppliers, [:company_id, :company_type])
#
# # Check a unique index exists
# index_exists?(:suppliers, :company_id, unique: true)
#
# # Check an index with a custom name exists
# index_exists?(:suppliers, :company_id, name: "idx_company_id")
#
def index_exists?(table_name, column_name, options = {})
column_names = Array(column_name).map(&:to_s)
checks = []
checks << lambda { |i| i.columns == column_names }
checks << lambda { |i| i.unique } if options[:unique]
checks << lambda { |i| i.name == options[:name].to_s } if options[:name]
indexes(table_name).any? { |i| checks.all? { |check| check[i] } }
end
# Returns an array of Column objects for the table specified by +table_name+.
# See the concrete implementation for details on the expected parameter values.
def columns(table_name)
raise NotImplementedError, "#columns is not implemented"
end
# Checks to see if a column exists in a given table.
#
# # Check a column exists
# column_exists?(:suppliers, :name)
#
# # Check a column exists of a particular type
# column_exists?(:suppliers, :name, :string)
#
# # Check a column exists with a specific definition
# column_exists?(:suppliers, :name, :string, limit: 100)
# column_exists?(:suppliers, :name, :string, default: 'default')
# column_exists?(:suppliers, :name, :string, null: false)
# column_exists?(:suppliers, :tax, :decimal, precision: 8, scale: 2)
#
def column_exists?(table_name, column_name, type = nil, options = {})
column_name = column_name.to_s
checks = []
checks << lambda { |c| c.name == column_name }
checks << lambda { |c| c.type == type } if type
column_options_keys.each do |attr|
checks << lambda { |c| c.send(attr) == options[attr] } if options.key?(attr)
end
columns(table_name).any? { |c| checks.all? { |check| check[c] } }
end
# Returns just a table's primary key
def primary_key(table_name)
pk = primary_keys(table_name)
pk = pk.first unless pk.size > 1
pk
end
# Creates a new table with the name +table_name+. +table_name+ may either
# be a String or a Symbol.
#
# There are two ways to work with #create_table. You can use the block
# form or the regular form, like this:
#
# === Block form
#
# # create_table() passes a TableDefinition object to the block.
# # This form will not only create the table, but also columns for the
# # table.
#
# create_table(:suppliers) do |t|
# t.column :name, :string, limit: 60
# # Other fields here
# end
#
# === Block form, with shorthand
#
# # You can also use the column types as method calls, rather than calling the column method.
# create_table(:suppliers) do |t|
# t.string :name, limit: 60
# # Other fields here
# end
#
# === Regular form
#
# # Creates a table called 'suppliers' with no columns.
# create_table(:suppliers)
# # Add a column to 'suppliers'.
# add_column(:suppliers, :name, :string, {limit: 60})
#
# The +options+ hash can include the following keys:
# [:id]
# Whether to automatically add a primary key column. Defaults to true.
# Join tables for {ActiveRecord::Base.has_and_belongs_to_many}[rdoc-ref:Associations::ClassMethods#has_and_belongs_to_many] should set it to false.
#
# A Symbol can be used to specify the type of the generated primary key column.
# [:primary_key]
# The name of the primary key, if one is to be added automatically.
# Defaults to +id+. If :id is false, then this option is ignored.
#
# Note that Active Record models will automatically detect their
# primary key. This can be avoided by using
# {self.primary_key=}[rdoc-ref:AttributeMethods::PrimaryKey::ClassMethods#primary_key=] on the model
# to define the key explicitly.
#
# [:options]
# Any extra options you want appended to the table definition.
# [:temporary]
# Make a temporary table.
# [:force]
# Set to true to drop the table before creating it.
# Set to +:cascade+ to drop dependent objects as well.
# Defaults to false.
# [:as]
# SQL to use to generate the table. When this option is used, the block is
# ignored, as are the :id and :primary_key options.
#
# ====== Add a backend specific option to the generated SQL (MySQL)
#
# create_table(:suppliers, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
#
# generates:
#
# CREATE TABLE suppliers (
# id int auto_increment PRIMARY KEY
# ) ENGINE=InnoDB DEFAULT CHARSET=utf8
#
# ====== Rename the primary key column
#
# create_table(:objects, primary_key: 'guid') do |t|
# t.column :name, :string, limit: 80
# end
#
# generates:
#
# CREATE TABLE objects (
# guid int auto_increment PRIMARY KEY,
# name varchar(80)
# )
#
# ====== Change the primary key column type
#
# create_table(:tags, id: :string) do |t|
# t.column :label, :string
# end
#
# generates:
#
# CREATE TABLE tags (
# id varchar PRIMARY KEY,
# label varchar
# )
#
# ====== Do not add a primary key column
#
# create_table(:categories_suppliers, id: false) do |t|
# t.column :category_id, :integer
# t.column :supplier_id, :integer
# end
#
# generates:
#
# CREATE TABLE categories_suppliers (
# category_id int,
# supplier_id int
# )
#
# ====== Create a temporary table based on a query
#
# create_table(:long_query, temporary: true,
# as: "SELECT * FROM orders INNER JOIN line_items ON order_id=orders.id")
#
# generates:
#
# CREATE TEMPORARY TABLE long_query AS
# SELECT * FROM orders INNER JOIN line_items ON order_id=orders.id
#
# See also TableDefinition#column for details on how to create columns.
def create_table(table_name, comment: nil, **options)
td = create_table_definition table_name, options[:temporary], options[:options], options[:as], comment: comment
if options[:id] != false && !options[:as]
pk = options.fetch(:primary_key) do
Base.get_primary_key table_name.to_s.singularize
end
if pk.is_a?(Array)
td.primary_keys pk
else
td.primary_key pk, options.fetch(:id, :primary_key), options
end
end
yield td if block_given?
if options[:force]
drop_table(table_name, **options, if_exists: true)
end
result = execute schema_creation.accept td
unless supports_indexes_in_create?
td.indexes.each do |column_name, index_options|
add_index(table_name, column_name, index_options)
end
end
if supports_comments? && !supports_comments_in_create?
change_table_comment(table_name, comment) if comment.present?
td.columns.each do |column|
change_column_comment(table_name, column.name, column.comment) if column.comment.present?
end
end
result
end
# Creates a new join table with the name created using the lexical order of the first two
# arguments. These arguments can be a String or a Symbol.
#
# # Creates a table called 'assemblies_parts' with no id.
# create_join_table(:assemblies, :parts)
#
# You can pass an +options+ hash which can include the following keys:
# [:table_name]
# Sets the table name, overriding the default.
# [:column_options]
# Any extra options you want appended to the columns definition.
# [:options]
# Any extra options you want appended to the table definition.
# [:temporary]
# Make a temporary table.
# [:force]
# Set to true to drop the table before creating it.
# Defaults to false.
#
# Note that #create_join_table does not create any indices by default; you can use
# its block form to do so yourself:
#
# create_join_table :products, :categories do |t|
# t.index :product_id
# t.index :category_id
# end
#
# ====== Add a backend specific option to the generated SQL (MySQL)
#
# create_join_table(:assemblies, :parts, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
#
# generates:
#
# CREATE TABLE assemblies_parts (
# assembly_id int NOT NULL,
# part_id int NOT NULL,
# ) ENGINE=InnoDB DEFAULT CHARSET=utf8
#
def create_join_table(table_1, table_2, column_options: {}, **options)
join_table_name = find_join_table_name(table_1, table_2, options)
column_options.reverse_merge!(null: false, index: false)
t1_ref, t2_ref = [table_1, table_2].map { |t| t.to_s.singularize }
create_table(join_table_name, options.merge!(id: false)) do |td|
td.references t1_ref, column_options
td.references t2_ref, column_options
yield td if block_given?
end
end
# Drops the join table specified by the given arguments.
# See #create_join_table for details.
#
# Although this command ignores the block if one is given, it can be helpful
# to provide one in a migration's +change+ method so it can be reverted.
# In that case, the block will be used by #create_join_table.
def drop_join_table(table_1, table_2, options = {})
join_table_name = find_join_table_name(table_1, table_2, options)
drop_table(join_table_name)
end
# A block for changing columns in +table+.
#
# # change_table() yields a Table instance
# change_table(:suppliers) do |t|
# t.column :name, :string, limit: 60
# # Other column alterations here
# end
#
# The +options+ hash can include the following keys:
# [:bulk]
# Set this to true to make this a bulk alter query, such as
#
# ALTER TABLE `users` ADD COLUMN age INT, ADD COLUMN birthdate DATETIME ...
#
# Defaults to false.
#
# ====== Add a column
#
# change_table(:suppliers) do |t|
# t.column :name, :string, limit: 60
# end
#
# ====== Add 2 integer columns
#
# change_table(:suppliers) do |t|
# t.integer :width, :height, null: false, default: 0
# end
#
# ====== Add created_at/updated_at columns
#
# change_table(:suppliers) do |t|
# t.timestamps
# end
#
# ====== Add a foreign key column
#
# change_table(:suppliers) do |t|
# t.references :company
# end
#
# Creates a company_id(integer) column.
#
# ====== Add a polymorphic foreign key column
#
# change_table(:suppliers) do |t|
# t.belongs_to :company, polymorphic: true
# end
#
# Creates company_type(varchar) and company_id(integer) columns.
#
# ====== Remove a column
#
# change_table(:suppliers) do |t|
# t.remove :company
# end
#
# ====== Remove several columns
#
# change_table(:suppliers) do |t|
# t.remove :company_id
# t.remove :width, :height
# end
#
# ====== Remove an index
#
# change_table(:suppliers) do |t|
# t.remove_index :company_id
# end
#
# See also Table for details on all of the various column transformations.
def change_table(table_name, options = {})
if supports_bulk_alter? && options[:bulk]
recorder = ActiveRecord::Migration::CommandRecorder.new(self)
yield update_table_definition(table_name, recorder)
bulk_change_table(table_name, recorder.commands)
else
yield update_table_definition(table_name, self)
end
end
# Renames a table.
#
# rename_table('octopuses', 'octopi')
#
def rename_table(table_name, new_name)
raise NotImplementedError, "rename_table is not implemented"
end
# Drops a table from the database.
#
# [:force]
# Set to +:cascade+ to drop dependent objects as well.
# Defaults to false.
# [:if_exists]
# Set to +true+ to only drop the table if it exists.
# Defaults to false.
#
# Although this command ignores most +options+ and the block if one is given,
# it can be helpful to provide these in a migration's +change+ method so it can be reverted.
# In that case, +options+ and the block will be used by #create_table.
def drop_table(table_name, options = {})
execute "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}"
end
# Add a new +type+ column named +column_name+ to +table_name+.
#
# The +type+ parameter is normally one of the migrations native types,
# which is one of the following:
# :primary_key, :string, :text,
# :integer, :bigint, :float, :decimal, :numeric,
# :datetime, :time, :date,
# :binary, :boolean.
#
# You may use a type not in this list as long as it is supported by your
# database (for example, "polygon" in MySQL), but this will not be database
# agnostic and should usually be avoided.
#
# Available options are (none of these exists by default):
# * :limit -
# Requests a maximum column length. This is the number of characters for a :string column
# and number of bytes for :text, :binary and :integer columns.
# * :default -
# The column's default value. Use +nil+ for +NULL+.
# * :null -
# Allows or disallows +NULL+ values in the column. This option could
# have been named :null_allowed.
# * :precision -
# Specifies the precision for the :decimal and :numeric columns.
# * :scale -
# Specifies the scale for the :decimal and :numeric columns.
#
# Note: The precision is the total number of significant digits,
# and the scale is the number of digits that can be stored following
# the decimal point. For example, the number 123.45 has a precision of 5
# and a scale of 2. A decimal with a precision of 5 and a scale of 2 can
# range from -999.99 to 999.99.
#
# Please be aware of different RDBMS implementations behavior with
# :decimal columns:
# * The SQL standard says the default scale should be 0, :scale <=
# :precision, and makes no comments about the requirements of
# :precision.
# * MySQL: :precision [1..63], :scale [0..30].
# Default is (10,0).
# * PostgreSQL: :precision [1..infinity],
# :scale [0..infinity]. No default.
# * SQLite3: No restrictions on :precision and :scale,
# but the maximum supported :precision is 16. No default.
# * Oracle: :precision [1..38], :scale [-84..127].
# Default is (38,0).
# * DB2: :precision [1..63], :scale [0..62].
# Default unknown.
# * SqlServer: :precision [1..38], :scale [0..38].
# Default (38,0).
#
# == Examples
#
# add_column(:users, :picture, :binary, limit: 2.megabytes)
# # ALTER TABLE "users" ADD "picture" blob(2097152)
#
# add_column(:articles, :status, :string, limit: 20, default: 'draft', null: false)
# # ALTER TABLE "articles" ADD "status" varchar(20) DEFAULT 'draft' NOT NULL
#
# add_column(:answers, :bill_gates_money, :decimal, precision: 15, scale: 2)
# # ALTER TABLE "answers" ADD "bill_gates_money" decimal(15,2)
#
# add_column(:measurements, :sensor_reading, :decimal, precision: 30, scale: 20)
# # ALTER TABLE "measurements" ADD "sensor_reading" decimal(30,20)
#
# # While :scale defaults to zero on most databases, it
# # probably wouldn't hurt to include it.
# add_column(:measurements, :huge_integer, :decimal, precision: 30)
# # ALTER TABLE "measurements" ADD "huge_integer" decimal(30)
#
# # Defines a column that stores an array of a type.
# add_column(:users, :skills, :text, array: true)
# # ALTER TABLE "users" ADD "skills" text[]
#
# # Defines a column with a database-specific type.
# add_column(:shapes, :triangle, 'polygon')
# # ALTER TABLE "shapes" ADD "triangle" polygon
def add_column(table_name, column_name, type, options = {})
at = create_alter_table table_name
at.add_column(column_name, type, options)
execute schema_creation.accept at
end
# Removes the given columns from the table definition.
#
# remove_columns(:suppliers, :qualification, :experience)
#
def remove_columns(table_name, *column_names)
raise ArgumentError.new("You must specify at least one column name. Example: remove_columns(:people, :first_name)") if column_names.empty?
column_names.each do |column_name|
remove_column(table_name, column_name)
end
end
# Removes the column from the table definition.
#
# remove_column(:suppliers, :qualification)
#
# The +type+ and +options+ parameters will be ignored if present. It can be helpful
# to provide these in a migration's +change+ method so it can be reverted.
# In that case, +type+ and +options+ will be used by #add_column.
def remove_column(table_name, column_name, type = nil, options = {})
execute "ALTER TABLE #{quote_table_name(table_name)} DROP #{quote_column_name(column_name)}"
end
# Changes the column's definition according to the new options.
# See TableDefinition#column for details of the options you can use.
#
# change_column(:suppliers, :name, :string, limit: 80)
# change_column(:accounts, :description, :text)
#
def change_column(table_name, column_name, type, options = {})
raise NotImplementedError, "change_column is not implemented"
end
# Sets a new default value for a column:
#
# change_column_default(:suppliers, :qualification, 'new')
# change_column_default(:accounts, :authorized, 1)
#
# Setting the default to +nil+ effectively drops the default:
#
# change_column_default(:users, :email, nil)
#
# Passing a hash containing +:from+ and +:to+ will make this change
# reversible in migration:
#
# change_column_default(:posts, :state, from: nil, to: "draft")
#
def change_column_default(table_name, column_name, default_or_changes)
raise NotImplementedError, "change_column_default is not implemented"
end
# Sets or removes a NOT NULL constraint on a column. The +null+ flag
# indicates whether the value can be +NULL+. For example
#
# change_column_null(:users, :nickname, false)
#
# says nicknames cannot be +NULL+ (adds the constraint), whereas
#
# change_column_null(:users, :nickname, true)
#
# allows them to be +NULL+ (drops the constraint).
#
# The method accepts an optional fourth argument to replace existing
# NULLs with some other value. Use that one when enabling the
# constraint if needed, since otherwise those rows would not be valid.
#
# Please note the fourth argument does not set a column's default.
def change_column_null(table_name, column_name, null, default = nil)
raise NotImplementedError, "change_column_null is not implemented"
end
# Renames a column.
#
# rename_column(:suppliers, :description, :name)
#
def rename_column(table_name, column_name, new_column_name)
raise NotImplementedError, "rename_column is not implemented"
end
# Adds a new index to the table. +column_name+ can be a single Symbol, or
# an Array of Symbols.
#
# The index will be named after the table and the column name(s), unless
# you pass :name as an option.
#
# ====== Creating a simple index
#
# add_index(:suppliers, :name)
#
# generates:
#
# CREATE INDEX suppliers_name_index ON suppliers(name)
#
# ====== Creating a unique index
#
# add_index(:accounts, [:branch_id, :party_id], unique: true)
#
# generates:
#
# CREATE UNIQUE INDEX accounts_branch_id_party_id_index ON accounts(branch_id, party_id)
#
# ====== Creating a named index
#
# add_index(:accounts, [:branch_id, :party_id], unique: true, name: 'by_branch_party')
#
# generates:
#
# CREATE UNIQUE INDEX by_branch_party ON accounts(branch_id, party_id)
#
# ====== Creating an index with specific key length
#
# add_index(:accounts, :name, name: 'by_name', length: 10)
#
# generates:
#
# CREATE INDEX by_name ON accounts(name(10))
#
# ====== Creating an index with specific key lengths for multiple keys
#
# add_index(:accounts, [:name, :surname], name: 'by_name_surname', length: {name: 10, surname: 15})
#
# generates:
#
# CREATE INDEX by_name_surname ON accounts(name(10), surname(15))
#
# Note: SQLite doesn't support index length.
#
# ====== Creating an index with a sort order (desc or asc, asc is the default)
#
# add_index(:accounts, [:branch_id, :party_id, :surname], order: {branch_id: :desc, party_id: :asc})
#
# generates:
#
# CREATE INDEX by_branch_desc_party ON accounts(branch_id DESC, party_id ASC, surname)
#
# Note: MySQL doesn't yet support index order (it accepts the syntax but ignores it).
#
# ====== Creating a partial index
#
# add_index(:accounts, [:branch_id, :party_id], unique: true, where: "active")
#
# generates:
#
# CREATE UNIQUE INDEX index_accounts_on_branch_id_and_party_id ON accounts(branch_id, party_id) WHERE active
#
# Note: Partial indexes are only supported for PostgreSQL and SQLite 3.8.0+.
#
# ====== Creating an index with a specific method
#
# add_index(:developers, :name, using: 'btree')
#
# generates:
#
# CREATE INDEX index_developers_on_name ON developers USING btree (name) -- PostgreSQL
# CREATE INDEX index_developers_on_name USING btree ON developers (name) -- MySQL
#
# Note: only supported by PostgreSQL and MySQL
#
# ====== Creating an index with a specific type
#
# add_index(:developers, :name, type: :fulltext)
#
# generates:
#
# CREATE FULLTEXT INDEX index_developers_on_name ON developers (name) -- MySQL
#
# Note: only supported by MySQL.
def add_index(table_name, column_name, options = {})
index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options}"
end
# Removes the given index from the table.
#
# Removes the index on +branch_id+ in the +accounts+ table if exactly one such index exists.
#
# remove_index :accounts, :branch_id
#
# Removes the index on +branch_id+ in the +accounts+ table if exactly one such index exists.
#
# remove_index :accounts, column: :branch_id
#
# Removes the index on +branch_id+ and +party_id+ in the +accounts+ table if exactly one such index exists.
#
# remove_index :accounts, column: [:branch_id, :party_id]
#
# Removes the index named +by_branch_party+ in the +accounts+ table.
#
# remove_index :accounts, name: :by_branch_party
#
def remove_index(table_name, options = {})
index_name = index_name_for_remove(table_name, options)
execute "DROP INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)}"
end
# Renames an index.
#
# Rename the +index_people_on_last_name+ index to +index_users_on_last_name+:
#
# rename_index :people, 'index_people_on_last_name', 'index_users_on_last_name'
#
def rename_index(table_name, old_name, new_name)
validate_index_length!(table_name, new_name)
# this is a naive implementation; some DBs may support this more efficiently (Postgres, for instance)
old_index_def = indexes(table_name).detect { |i| i.name == old_name }
return unless old_index_def
add_index(table_name, old_index_def.columns, name: new_name, unique: old_index_def.unique)
remove_index(table_name, name: old_name)
end
def index_name(table_name, options) #:nodoc:
if Hash === options
if options[:column]
"index_#{table_name}_on_#{Array(options[:column]) * '_and_'}"
elsif options[:name]
options[:name]
else
raise ArgumentError, "You must specify the index name"
end
else
index_name(table_name, index_name_options(options))
end
end
# Verifies the existence of an index with a given name.
def index_name_exists?(table_name, index_name, default = nil)
unless default.nil?
ActiveSupport::Deprecation.warn(<<-MSG.squish)
Passing default to #index_name_exists? is deprecated without replacement.
MSG
end
index_name = index_name.to_s
indexes(table_name).detect { |i| i.name == index_name }
end
# Adds a reference. The reference column is an integer by default,
# the :type option can be used to specify a different type.
# Optionally adds a +_type+ column, if :polymorphic option is provided.
# #add_reference and #add_belongs_to are acceptable.
#
# The +options+ hash can include the following keys:
# [:type]
# The reference column type. Defaults to +:integer+.
# [:index]
# Add an appropriate index. Defaults to true.
# See #add_index for usage of this option.
# [:foreign_key]
# Add an appropriate foreign key constraint. Defaults to false.
# [:polymorphic]
# Whether an additional +_type+ column should be added. Defaults to false.
# [:null]
# Whether the column allows nulls. Defaults to true.
#
# ====== Create a user_id integer column
#
# add_reference(:products, :user)
#
# ====== Create a user_id string column
#
# add_reference(:products, :user, type: :string)
#
# ====== Create supplier_id, supplier_type columns and appropriate index
#
# add_reference(:products, :supplier, polymorphic: true, index: true)
#
# ====== Create a supplier_id column with a unique index
#
# add_reference(:products, :supplier, index: { unique: true })
#
# ====== Create a supplier_id column with a named index
#
# add_reference(:products, :supplier, index: { name: "my_supplier_index" })
#
# ====== Create a supplier_id column and appropriate foreign key
#
# add_reference(:products, :supplier, foreign_key: true)
#
# ====== Create a supplier_id column and a foreign key to the firms table
#
# add_reference(:products, :supplier, foreign_key: {to_table: :firms})
#
def add_reference(table_name, ref_name, **options)
ReferenceDefinition.new(ref_name, options).add_to(update_table_definition(table_name, self))
end
alias :add_belongs_to :add_reference
# Removes the reference(s). Also removes a +type+ column if one exists.
# #remove_reference and #remove_belongs_to are acceptable.
#
# ====== Remove the reference
#
# remove_reference(:products, :user, index: true)
#
# ====== Remove polymorphic reference
#
# remove_reference(:products, :supplier, polymorphic: true)
#
# ====== Remove the reference with a foreign key
#
# remove_reference(:products, :user, index: true, foreign_key: true)
#
def remove_reference(table_name, ref_name, foreign_key: false, polymorphic: false, **options)
if foreign_key
reference_name = Base.pluralize_table_names ? ref_name.to_s.pluralize : ref_name
if foreign_key.is_a?(Hash)
foreign_key_options = foreign_key
else
foreign_key_options = { to_table: reference_name }
end
foreign_key_options[:column] ||= "#{ref_name}_id"
remove_foreign_key(table_name, **foreign_key_options)
end
remove_column(table_name, "#{ref_name}_id")
remove_column(table_name, "#{ref_name}_type") if polymorphic
end
alias :remove_belongs_to :remove_reference
# Returns an array of foreign keys for the given table.
# The foreign keys are represented as ForeignKeyDefinition objects.
def foreign_keys(table_name)
raise NotImplementedError, "foreign_keys is not implemented"
end
# Adds a new foreign key. +from_table+ is the table with the key column,
# +to_table+ contains the referenced primary key.
#
# The foreign key will be named after the following pattern: fk_rails_.
# +identifier+ is a 10 character long string which is deterministically generated from the
# +from_table+ and +column+. A custom name can be specified with the :name option.
#
# ====== Creating a simple foreign key
#
# add_foreign_key :articles, :authors
#
# generates:
#
# ALTER TABLE "articles" ADD CONSTRAINT fk_rails_e74ce85cbc FOREIGN KEY ("author_id") REFERENCES "authors" ("id")
#
# ====== Creating a foreign key on a specific column
#
# add_foreign_key :articles, :users, column: :author_id, primary_key: "lng_id"
#
# generates:
#
# ALTER TABLE "articles" ADD CONSTRAINT fk_rails_58ca3d3a82 FOREIGN KEY ("author_id") REFERENCES "users" ("lng_id")
#
# ====== Creating a cascading foreign key
#
# add_foreign_key :articles, :authors, on_delete: :cascade
#
# generates:
#
# ALTER TABLE "articles" ADD CONSTRAINT fk_rails_e74ce85cbc FOREIGN KEY ("author_id") REFERENCES "authors" ("id") ON DELETE CASCADE
#
# The +options+ hash can include the following keys:
# [:column]
# The foreign key column name on +from_table+. Defaults to to_table.singularize + "_id"
# [:primary_key]
# The primary key column name on +to_table+. Defaults to +id+.
# [:name]
# The constraint name. Defaults to fk_rails_.
# [:on_delete]
# Action that happens ON DELETE. Valid values are +:nullify+, +:cascade+ and +:restrict+
# [:on_update]
# Action that happens ON UPDATE. Valid values are +:nullify+, +:cascade+ and +:restrict+
def add_foreign_key(from_table, to_table, options = {})
return unless supports_foreign_keys?
options = foreign_key_options(from_table, to_table, options)
at = create_alter_table from_table
at.add_foreign_key to_table, options
execute schema_creation.accept(at)
end
# Removes the given foreign key from the table. Any option parameters provided
# will be used to re-add the foreign key in case of a migration rollback.
# It is recommended that you provide any options used when creating the foreign
# key so that the migration can be reverted properly.
#
# Removes the foreign key on +accounts.branch_id+.
#
# remove_foreign_key :accounts, :branches
#
# Removes the foreign key on +accounts.owner_id+.
#
# remove_foreign_key :accounts, column: :owner_id
#
# Removes the foreign key named +special_fk_name+ on the +accounts+ table.
#
# remove_foreign_key :accounts, name: :special_fk_name
#
# The +options+ hash accepts the same keys as SchemaStatements#add_foreign_key.
def remove_foreign_key(from_table, options_or_to_table = {})
return unless supports_foreign_keys?
fk_name_to_delete = foreign_key_for!(from_table, options_or_to_table).name
at = create_alter_table from_table
at.drop_foreign_key fk_name_to_delete
execute schema_creation.accept(at)
end
# Checks to see if a foreign key exists on a table for a given foreign key definition.
#
# # Checks to see if a foreign key exists.
# foreign_key_exists?(:accounts, :branches)
#
# # Checks to see if a foreign key on a specified column exists.
# foreign_key_exists?(:accounts, column: :owner_id)
#
# # Checks to see if a foreign key with a custom name exists.
# foreign_key_exists?(:accounts, name: "special_fk_name")
#
def foreign_key_exists?(from_table, options_or_to_table = {})
foreign_key_for(from_table, options_or_to_table).present?
end
def foreign_key_for(from_table, options_or_to_table = {}) # :nodoc:
return unless supports_foreign_keys?
foreign_keys(from_table).detect { |fk| fk.defined_for? options_or_to_table }
end
def foreign_key_for!(from_table, options_or_to_table = {}) # :nodoc:
foreign_key_for(from_table, options_or_to_table) || \
raise(ArgumentError, "Table '#{from_table}' has no foreign key for #{options_or_to_table}")
end
def foreign_key_column_for(table_name) # :nodoc:
prefix = Base.table_name_prefix
suffix = Base.table_name_suffix
name = table_name.to_s =~ /#{prefix}(.+)#{suffix}/ ? $1 : table_name.to_s
"#{name.singularize}_id"
end
def foreign_key_options(from_table, to_table, options) # :nodoc:
options = options.dup
options[:column] ||= foreign_key_column_for(to_table)
options[:name] ||= foreign_key_name(from_table, options)
options
end
def dump_schema_information #:nodoc:
versions = ActiveRecord::SchemaMigration.all_versions
insert_versions_sql(versions) if versions.any?
end
def insert_versions_sql(versions) # :nodoc:
sm_table = quote_table_name(ActiveRecord::SchemaMigration.table_name)
if versions.is_a?(Array)
sql = "INSERT INTO #{sm_table} (version) VALUES\n"
sql << versions.map { |v| "(#{quote(v)})" }.join(",\n")
sql << ";\n\n"
sql
else
"INSERT INTO #{sm_table} (version) VALUES (#{quote(versions)});"
end
end
def initialize_schema_migrations_table # :nodoc:
ActiveRecord::SchemaMigration.create_table
end
deprecate :initialize_schema_migrations_table
def initialize_internal_metadata_table # :nodoc:
ActiveRecord::InternalMetadata.create_table
end
deprecate :initialize_internal_metadata_table
def internal_string_options_for_primary_key # :nodoc:
{ primary_key: true }
end
def assume_migrated_upto_version(version, migrations_paths)
migrations_paths = Array(migrations_paths)
version = version.to_i
sm_table = quote_table_name(ActiveRecord::SchemaMigration.table_name)
migrated = ActiveRecord::SchemaMigration.all_versions.map(&:to_i)
versions = ActiveRecord::Migrator.migration_files(migrations_paths).map do |file|
ActiveRecord::Migrator.parse_migration_filename(file).first.to_i
end
unless migrated.include?(version)
execute "INSERT INTO #{sm_table} (version) VALUES (#{quote(version)})"
end
inserting = (versions - migrated).select { |v| v < version }
if inserting.any?
if (duplicate = inserting.detect { |v| inserting.count(v) > 1 })
raise "Duplicate migration #{duplicate}. Please renumber your migrations to resolve the conflict."
end
if supports_multi_insert?
execute insert_versions_sql(inserting)
else
inserting.each do |v|
execute insert_versions_sql(v)
end
end
end
end
def type_to_sql(type, limit: nil, precision: nil, scale: nil, **) # :nodoc:
type = type.to_sym if type
if native = native_database_types[type]
column_type_sql = (native.is_a?(Hash) ? native[:name] : native).dup
if type == :decimal # ignore limit, use precision and scale
scale ||= native[:scale]
if precision ||= native[:precision]
if scale
column_type_sql << "(#{precision},#{scale})"
else
column_type_sql << "(#{precision})"
end
elsif scale
raise ArgumentError, "Error adding decimal column: precision cannot be empty if scale is specified"
end
elsif [:datetime, :timestamp, :time, :interval].include?(type) && precision ||= native[:precision]
if (0..6) === precision
column_type_sql << "(#{precision})"
else
raise(ActiveRecordError, "No #{native[:name]} type has precision of #{precision}. The allowed range of precision is from 0 to 6")
end
elsif (type != :primary_key) && (limit ||= native.is_a?(Hash) && native[:limit])
column_type_sql << "(#{limit})"
end
column_type_sql
else
type.to_s
end
end
# Given a set of columns and an ORDER BY clause, returns the columns for a SELECT DISTINCT.
# PostgreSQL, MySQL, and Oracle override this for custom DISTINCT syntax - they
# require the order columns appear in the SELECT.
#
# columns_for_distinct("posts.id", ["posts.created_at desc"])
#
def columns_for_distinct(columns, orders) # :nodoc:
columns
end
# Adds timestamps (+created_at+ and +updated_at+) columns to +table_name+.
# Additional options (like +:null+) are forwarded to #add_column.
#
# add_timestamps(:suppliers, null: true)
#
def add_timestamps(table_name, options = {})
options[:null] = false if options[:null].nil?
add_column table_name, :created_at, :datetime, options
add_column table_name, :updated_at, :datetime, options
end
# Removes the timestamp columns (+created_at+ and +updated_at+) from the table definition.
#
# remove_timestamps(:suppliers)
#
def remove_timestamps(table_name, options = {})
remove_column table_name, :updated_at
remove_column table_name, :created_at
end
def update_table_definition(table_name, base) #:nodoc:
Table.new(table_name, base)
end
def add_index_options(table_name, column_name, comment: nil, **options) # :nodoc:
column_names = index_column_names(column_name)
options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm, :type)
index_type = options[:type].to_s if options.key?(:type)
index_type ||= options[:unique] ? "UNIQUE" : ""
index_name = options[:name].to_s if options.key?(:name)
index_name ||= index_name(table_name, column_names)
if options.key?(:algorithm)
algorithm = index_algorithms.fetch(options[:algorithm]) {
raise ArgumentError.new("Algorithm must be one of the following: #{index_algorithms.keys.map(&:inspect).join(', ')}")
}
end
using = "USING #{options[:using]}" if options[:using].present?
if supports_partial_index?
index_options = options[:where] ? " WHERE #{options[:where]}" : ""
end
validate_index_length!(table_name, index_name, options.fetch(:internal, false))
if data_source_exists?(table_name) && index_name_exists?(table_name, index_name)
raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' already exists"
end
index_columns = quoted_columns_for_index(column_names, options).join(", ")
[index_name, index_type, index_columns, index_options, algorithm, using, comment]
end
def options_include_default?(options)
options.include?(:default) && !(options[:null] == false && options[:default].nil?)
end
# Changes the comment for a table or removes it if +nil+.
def change_table_comment(table_name, comment)
raise NotImplementedError, "#{self.class} does not support changing table comments"
end
# Changes the comment for a column or removes it if +nil+.
def change_column_comment(table_name, column_name, comment) #:nodoc:
raise NotImplementedError, "#{self.class} does not support changing column comments"
end
private
def column_options_keys
[:limit, :precision, :scale, :default, :null, :collation, :comment]
end
def add_index_sort_order(quoted_columns, **options)
if order = options[:order]
case order
when Hash
order = order.symbolize_keys
quoted_columns.each { |name, column| column << " #{order[name].upcase}" if order[name].present? }
when String
quoted_columns.each { |name, column| column << " #{order.upcase}" if order.present? }
end
end
quoted_columns
end
# Overridden by the MySQL adapter for supporting index lengths
def add_options_for_index_columns(quoted_columns, **options)
if supports_index_sort_order?
quoted_columns = add_index_sort_order(quoted_columns, options)
end
quoted_columns
end
def quoted_columns_for_index(column_names, **options)
return [column_names] if column_names.is_a?(String)
quoted_columns = Hash[column_names.map { |name| [name.to_sym, quote_column_name(name).dup] }]
add_options_for_index_columns(quoted_columns, options).values
end
def index_name_for_remove(table_name, options = {})
return options[:name] if can_remove_index_by_name?(options)
checks = []
if options.is_a?(Hash)
checks << lambda { |i| i.name == options[:name].to_s } if options.key?(:name)
column_names = index_column_names(options[:column])
else
column_names = index_column_names(options)
end
if column_names.present?
checks << lambda { |i| index_name(table_name, i.columns) == index_name(table_name, column_names) }
end
raise ArgumentError, "No name or columns specified" if checks.none?
matching_indexes = indexes(table_name).select { |i| checks.all? { |check| check[i] } }
if matching_indexes.count > 1
raise ArgumentError, "Multiple indexes found on #{table_name} columns #{column_names}. " \
"Specify an index name from #{matching_indexes.map(&:name).join(', ')}"
elsif matching_indexes.none?
raise ArgumentError, "No indexes found on #{table_name} with the options provided."
else
matching_indexes.first.name
end
end
def rename_table_indexes(table_name, new_name)
indexes(new_name).each do |index|
generated_index_name = index_name(table_name, column: index.columns)
if generated_index_name == index.name
rename_index new_name, generated_index_name, index_name(new_name, column: index.columns)
end
end
end
def rename_column_indexes(table_name, column_name, new_column_name)
column_name, new_column_name = column_name.to_s, new_column_name.to_s
indexes(table_name).each do |index|
next unless index.columns.include?(new_column_name)
old_columns = index.columns.dup
old_columns[old_columns.index(new_column_name)] = column_name
generated_index_name = index_name(table_name, column: old_columns)
if generated_index_name == index.name
rename_index table_name, generated_index_name, index_name(table_name, column: index.columns)
end
end
end
def create_table_definition(*args)
TableDefinition.new(*args)
end
def create_alter_table(name)
AlterTable.new create_table_definition(name)
end
def index_column_names(column_names)
if column_names.is_a?(String) && /\W/.match?(column_names)
column_names
else
Array(column_names)
end
end
def index_name_options(column_names)
if column_names.is_a?(String) && /\W/.match?(column_names)
column_names = column_names.scan(/\w+/).join("_")
end
{ column: column_names }
end
def foreign_key_name(table_name, options)
identifier = "#{table_name}_#{options.fetch(:column)}_fk"
hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
options.fetch(:name) do
"fk_rails_#{hashed_identifier}"
end
end
def validate_index_length!(table_name, new_name, internal = false)
max_index_length = internal ? index_name_length : allowed_index_name_length
if new_name.length > max_index_length
raise ArgumentError, "Index name '#{new_name}' on table '#{table_name}' is too long; the limit is #{allowed_index_name_length} characters"
end
end
def extract_new_default_value(default_or_changes)
if default_or_changes.is_a?(Hash) && default_or_changes.has_key?(:from) && default_or_changes.has_key?(:to)
default_or_changes[:to]
else
default_or_changes
end
end
def can_remove_index_by_name?(options)
options.is_a?(Hash) && options.key?(:name) && options.except(:name, :algorithm).empty?
end
def data_source_sql(name = nil, type: nil)
raise NotImplementedError
end
def quoted_scope(name = nil, type: nil)
raise NotImplementedError
end
end
end
end