activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
# frozen_string_literal: true
require "active_support/core_ext/string/access"
require "openssl"
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 usable to back Active Record models.
# For most adapters this means all #tables and #views.
def data_sources
query_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)
query_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
query_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)
query_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
query_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)
query_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)
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")
#
# # Check a valid index exists (PostgreSQL only)
# index_exists?(:suppliers, :company_id, valid: true)
#
def index_exists?(table_name, column_name, **options)
indexes(table_name).any? { |i| i.defined_for?(column_name, **options) }
end
# Returns an array of +Column+ objects for the table specified by +table_name+.
def columns(table_name)
table_name = table_name.to_s
definitions = column_definitions(table_name)
definitions.map do |field|
new_column_from_field(table_name, field, definitions)
end
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
# #
# # This works for standard non-casted types (eg. string) but is unreliable
# # for types that may get cast to something else (eg. char, bigint).
# 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.to_sym rescue nil } 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:
# [<tt>:id</tt>]
# 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.
# [<tt>:primary_key</tt>]
# The name of the primary key, if one is to be added automatically.
# Defaults to +id+. If <tt>:id</tt> is false, then this option is ignored.
#
# If an array is passed, a composite primary key will be created.
#
# 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.
#
# [<tt>:options</tt>]
# Any extra options you want appended to the table definition.
# [<tt>:temporary</tt>]
# Make a temporary table.
# [<tt>:force</tt>]
# Set to true to drop the table before creating it.
# Set to +:cascade+ to drop dependent objects as well.
# Defaults to false.
# [<tt>:if_not_exists</tt>]
# Set to true to avoid raising an error when the table already exists.
# Defaults to false.
# [<tt>:as</tt>]
# SQL to use to generate the table. When this option is used, the block is
# ignored, as are the <tt>:id</tt> and <tt>:primary_key</tt> options.
#
# ====== Add a backend specific option to the generated SQL (MySQL)
#
# create_table(:suppliers, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8mb4')
#
# generates:
#
# CREATE TABLE suppliers (
# id bigint auto_increment PRIMARY KEY
# ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
#
# ====== 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 bigint 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
# )
#
# ====== Create a composite primary key
#
# create_table(:orders, primary_key: [:product_id, :client_id]) do |t|
# t.belongs_to :product
# t.belongs_to :client
# end
#
# generates:
#
# CREATE TABLE orders (
# product_id bigint NOT NULL,
# client_id bigint NOT NULL
# );
#
# ALTER TABLE ONLY "orders"
# ADD CONSTRAINT orders_pkey PRIMARY KEY (product_id, client_id);
#
# ====== Do not add a primary key column
#
# create_table(:categories_suppliers, id: false) do |t|
# t.column :category_id, :bigint
# t.column :supplier_id, :bigint
# end
#
# generates:
#
# CREATE TABLE categories_suppliers (
# category_id bigint,
# supplier_id bigint
# )
#
# ====== 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, id: :primary_key, primary_key: nil, force: nil, **options, &block)
validate_create_table_options!(options)
validate_table_length!(table_name) unless options[:_uses_legacy_table_name]
if force && options.key?(:if_not_exists)
raise ArgumentError, "Options `:force` and `:if_not_exists` cannot be used simultaneously."
end
td = build_create_table_definition(table_name, id: id, primary_key: primary_key, force: force, **options, &block)
if force
drop_table(table_name, force: force, if_exists: true)
else
schema_cache.clear_data_source_cache!(table_name.to_s)
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, if_not_exists: td.if_not_exists)
end
end
if supports_comments? && !supports_comments_in_create?
if table_comment = td.comment.presence
change_table_comment(table_name, table_comment)
end
td.columns.each do |column|
change_column_comment(table_name, column.name, column.comment) if column.comment.present?
end
end
result
end
# Returns a TableDefinition object containing information about the table that would be created
# if the same arguments were passed to #create_table. See #create_table for information about
# passing a +table_name+, and other additional options that can be passed.
def build_create_table_definition(table_name, id: :primary_key, primary_key: nil, force: nil, **options)
table_definition = create_table_definition(table_name, **options.extract!(*valid_table_definition_options, :_skip_validate_options))
table_definition.set_primary_key(table_name, id, primary_key, **options.extract!(*valid_primary_key_options, :_skip_validate_options))
yield table_definition if block_given?
table_definition
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:
# [<tt>:table_name</tt>]
# Sets the table name, overriding the default.
# [<tt>:column_options</tt>]
# Any extra options you want appended to the columns definition.
# [<tt>:options</tt>]
# Any extra options you want appended to the table definition.
# [<tt>:temporary</tt>]
# Make a temporary table.
# [<tt>:force</tt>]
# 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 bigint NOT NULL,
# part_id bigint 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| reference_name_for_table(t) }
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
# Builds a TableDefinition object for a join table.
#
# This definition object contains information about the table that would be created
# if the same arguments were passed to #create_join_table. See #create_join_table for
# information about what arguments should be passed.
def build_create_join_table_definition(table_1, table_2, column_options: {}, **options) # :nodoc:
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| reference_name_for_table(t) }
build_create_table_definition(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 and #drop_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, **options)
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:
# [<tt>:bulk</tt>]
# 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.
#
# Only supported on the MySQL and PostgreSQL adapter, ignored elsewhere.
#
# ====== Add a column
#
# change_table(:suppliers) do |t|
# t.column :name, :string, limit: 60
# end
#
# ====== Change type of a column
#
# change_table(:suppliers) do |t|
# t.change :metadata, :json
# 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 <tt>company_id(bigint)</tt> column.
#
# ====== Add a polymorphic foreign key column
#
# change_table(:suppliers) do |t|
# t.belongs_to :company, polymorphic: true
# end
#
# Creates <tt>company_type(varchar)</tt> and <tt>company_id(bigint)</tt> 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, base = self, **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, base)
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.
#
# [<tt>:force</tt>]
# Set to +:cascade+ to drop dependent objects as well.
# Defaults to false.
# [<tt>:if_exists</tt>]
# 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)
schema_cache.clear_data_source_cache!(table_name.to_s)
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+.
#
# See {ActiveRecord::ConnectionAdapters::TableDefinition.column}[rdoc-ref:ActiveRecord::ConnectionAdapters::TableDefinition#column].
#
# The +type+ parameter is normally one of the migrations native types,
# which is one of the following:
# <tt>:primary_key</tt>, <tt>:string</tt>, <tt>:text</tt>,
# <tt>:integer</tt>, <tt>:bigint</tt>, <tt>:float</tt>, <tt>:decimal</tt>, <tt>:numeric</tt>,
# <tt>:datetime</tt>, <tt>:time</tt>, <tt>:date</tt>,
# <tt>:binary</tt>, <tt>:blob</tt>, <tt>:boolean</tt>.
#
# 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):
# * <tt>:comment</tt> -
# Specifies the comment for the column. This option is ignored by some backends.
# * <tt>:collation</tt> -
# Specifies the collation for a <tt>:string</tt> or <tt>:text</tt> column.
# If not specified, the column will have the same collation as the table.
# * <tt>:default</tt> -
# The column's default value. Use +nil+ for +NULL+.
# * <tt>:limit</tt> -
# Requests a maximum column length. This is the number of characters for a <tt>:string</tt> column
# and number of bytes for <tt>:text</tt>, <tt>:binary</tt>, <tt>:blob</tt>, and <tt>:integer</tt> columns.
# This option is ignored by some backends.
# * <tt>:null</tt> -
# Allows or disallows +NULL+ values in the column.
# * <tt>:precision</tt> -
# Specifies the precision for the <tt>:decimal</tt>, <tt>:numeric</tt>,
# <tt>:datetime</tt>, and <tt>:time</tt> columns.
# * <tt>:scale</tt> -
# Specifies the scale for the <tt>:decimal</tt> and <tt>:numeric</tt> columns.
# * <tt>:if_not_exists</tt> -
# Specifies if the column already exists to not try to re-add it. This will avoid
# duplicate column errors.
#
# 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
# <tt>:decimal</tt> columns:
# * The SQL standard says the default scale should be 0, <tt>:scale</tt> <=
# <tt>:precision</tt>, and makes no comments about the requirements of
# <tt>:precision</tt>.
# * MySQL: <tt>:precision</tt> [1..65], <tt>:scale</tt> [0..30].
# Default is (10,0).
# * PostgreSQL: <tt>:precision</tt> [1..infinity],
# <tt>:scale</tt> [0..infinity]. No default.
# * SQLite3: No restrictions on <tt>:precision</tt> and <tt>:scale</tt>,
# but the maximum supported <tt>:precision</tt> is 16. No default.
# * Oracle: <tt>:precision</tt> [1..38], <tt>:scale</tt> [-84..127].
# Default is (38,0).
# * SqlServer: <tt>:precision</tt> [1..38], <tt>:scale</tt> [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
#
# # Ignores the method call if the column exists
# add_column(:shapes, :triangle, 'polygon', if_not_exists: true)
def add_column(table_name, column_name, type, **options)
add_column_def = build_add_column_definition(table_name, column_name, type, **options)
return unless add_column_def
execute schema_creation.accept(add_column_def)
end
def add_columns(table_name, *column_names, type:, **options) # :nodoc:
column_names.each do |column_name|
add_column(table_name, column_name, type, **options)
end
end
# Builds an AlterTable object for adding a column to a table.
#
# This definition object contains information about the column that would be created
# if the same arguments were passed to #add_column. See #add_column for information about
# passing a +table_name+, +column_name+, +type+ and other options that can be passed.
def build_add_column_definition(table_name, column_name, type, **options) # :nodoc:
return if options[:if_not_exists] == true && column_exists?(table_name, column_name)
if supports_datetime_with_precision?
if type == :datetime && !options.key?(:precision)
options[:precision] = 6
end
end
alter_table = create_alter_table(table_name)
alter_table.add_column(column_name, type, **options)
alter_table
end
# Removes the given columns from the table definition.
#
# remove_columns(:suppliers, :qualification, :experience)
#
# +type+ and other column options can be passed to make migration reversible.
#
# remove_columns(:suppliers, :qualification, :experience, type: :string, null: false)
def remove_columns(table_name, *column_names, type: nil, **options)
if column_names.empty?
raise ArgumentError.new("You must specify at least one column name. Example: remove_columns(:people, :first_name)")
end
remove_column_fragments = remove_columns_for_alter(table_name, *column_names, type: type, **options)
execute "ALTER TABLE #{quote_table_name(table_name)} #{remove_column_fragments.join(', ')}"
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.
# Depending on the database you're using, indexes using this column may be
# automatically removed or modified to remove this column from the index.
#
# If the options provided include an +if_exists+ key, it will be used to check if the
# column does not exist. This will silently ignore the migration rather than raising
# if the column was already used.
#
# remove_column(:suppliers, :qualification, if_exists: true)
def remove_column(table_name, column_name, type = nil, **options)
return if options[:if_exists] == true && !column_exists?(table_name, column_name)
execute "ALTER TABLE #{quote_table_name(table_name)} #{remove_column_for_alter(table_name, column_name, type, **options)}"
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
# Builds a ChangeColumnDefaultDefinition object.
#
# This definition object contains information about the column change that would occur
# if the same arguments were passed to #change_column_default. See #change_column_default for
# information about passing a +table_name+, +column_name+, +type+ and other options that can be passed.
def build_change_column_default_definition(table_name, column_name, default_or_changes) # :nodoc:
raise NotImplementedError, "build_change_column_default_definition is not implemented"
end
# Sets or removes a <tt>NOT NULL</tt> 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
# <tt>NULL</tt>s 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 <tt>:name</tt> as an option.
#
# ====== Creating a simple index
#
# add_index(:suppliers, :name)
#
# generates:
#
# CREATE INDEX index_suppliers_on_name ON suppliers(name)
#
# ====== Creating a index which already exists
#
# add_index(:suppliers, :name, if_not_exists: true)
#
# generates:
#
# CREATE INDEX IF NOT EXISTS index_suppliers_on_name ON suppliers(name)
#
# Note: Not supported by MySQL.
#
# ====== Creating a unique index
#
# add_index(:accounts, [:branch_id, :party_id], unique: true)
#
# generates:
#
# CREATE UNIQUE INDEX index_accounts_on_branch_id_and_party_id 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: only supported by MySQL
#
# ====== Creating an index with a sort order (desc or asc, asc is the default)
#
# add_index(:accounts, [:branch_id, :party_id, :surname], name: 'by_branch_desc_party', 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 only supports index order from 8.0.1 onwards (earlier versions accepted the syntax but ignored 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.
#
# ====== Creating an index that includes additional columns
#
# add_index(:accounts, :branch_id, include: :party_id)
#
# generates:
#
# CREATE INDEX index_accounts_on_branch_id ON accounts USING btree(branch_id) INCLUDE (party_id)
#
# Note: only supported by PostgreSQL.
#
# ====== 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 operator class
#
# add_index(:developers, :name, using: 'gist', opclass: :gist_trgm_ops)
# # CREATE INDEX developers_on_name ON developers USING gist (name gist_trgm_ops) -- PostgreSQL
#
# add_index(:developers, [:name, :city], using: 'gist', opclass: { city: :gist_trgm_ops })
# # CREATE INDEX developers_on_name_and_city ON developers USING gist (name, city gist_trgm_ops) -- PostgreSQL
#
# add_index(:developers, [:name, :city], using: 'gist', opclass: :gist_trgm_ops)
# # CREATE INDEX developers_on_name_and_city ON developers USING gist (name gist_trgm_ops, city gist_trgm_ops) -- PostgreSQL
#
# Note: only supported by PostgreSQL
#
# ====== 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.
#
# ====== Creating an index with a specific algorithm
#
# add_index(:developers, :name, algorithm: :concurrently)
# # CREATE INDEX CONCURRENTLY developers_on_name on developers (name) -- PostgreSQL
#
# add_index(:developers, :name, algorithm: :inplace)
# # CREATE INDEX `index_developers_on_name` ON `developers` (`name`) ALGORITHM = INPLACE -- MySQL
#
# Note: only supported by PostgreSQL and MySQL.
#
# Concurrently adding an index is not supported in a transaction.
#
# For more information see the {"Transactional Migrations" section}[rdoc-ref:Migration].
def add_index(table_name, column_name, **options)
create_index = build_create_index_definition(table_name, column_name, **options)
execute schema_creation.accept(create_index)
end
# Builds a CreateIndexDefinition object.
#
# This definition object contains information about the index that would be created
# if the same arguments were passed to #add_index. See #add_index for information about
# passing a +table_name+, +column_name+, and other additional options that can be passed.
def build_create_index_definition(table_name, column_name, **options) # :nodoc:
index, algorithm, if_not_exists = add_index_options(table_name, column_name, **options)
CreateIndexDefinition.new(index, algorithm, if_not_exists)
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
#
# Removes the index on +branch_id+ named +by_branch_party+ in the +accounts+ table.
#
# remove_index :accounts, :branch_id, name: :by_branch_party
#
# Checks if the index exists before trying to remove it. Will silently ignore indexes that
# don't exist.
#
# remove_index :accounts, if_exists: true
#
# Removes the index named +by_branch_party+ in the +accounts+ table +concurrently+.
#
# remove_index :accounts, name: :by_branch_party, algorithm: :concurrently
#
# Note: only supported by PostgreSQL.
#
# Concurrently removing an index is not supported in a transaction.
#
# For more information see the {"Transactional Migrations" section}[rdoc-ref:Migration].
def remove_index(table_name, column_name = nil, **options)
return if options[:if_exists] && !index_exists?(table_name, column_name, **options)
index_name = index_name_for_remove(table_name, column_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)
old_name = old_name.to_s
new_name = new_name.to_s
validate_index_length!(table_name, new_name)
# this is a naive implementation; some DBs may support this more efficiently (PostgreSQL, 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]
generate_index_name(table_name, options[:column])
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)
index_name = index_name.to_s
indexes(table_name).detect { |i| i.name == index_name }
end
# Adds a reference. The reference column is a bigint by default,
# the <tt>:type</tt> option can be used to specify a different type.
# Optionally adds a +_type+ column, if <tt>:polymorphic</tt> option is provided.
#
# The +options+ hash can include the following keys:
# [<tt>:type</tt>]
# The reference column type. Defaults to +:bigint+.
# [<tt>:index</tt>]
# Add an appropriate index. Defaults to true.
# See #add_index for usage of this option.
# [<tt>:foreign_key</tt>]
# Add an appropriate foreign key constraint. Defaults to false, pass true
# to add. In case the join table can't be inferred from the association
# pass <tt>:to_table</tt> with the appropriate table name.
# [<tt>:polymorphic</tt>]
# Whether an additional +_type+ column should be added. Defaults to false.
# [<tt>:null</tt>]
# Whether the column allows nulls. Defaults to true.
#
# ====== Create a user_id bigint column without an index
#
# add_reference(:products, :user, index: false)
#
# ====== Create a user_id string column
#
# add_reference(:products, :user, type: :string)
#
# ====== Create supplier_id, supplier_type columns
#
# add_reference(:products, :supplier, polymorphic: 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(table_name, self)
end
alias :add_belongs_to :add_reference
# Removes the reference(s). Also removes a +type+ column if one exists.
#
# ====== Remove the reference
#
# remove_reference(:products, :user, index: false)
#
# ====== Remove polymorphic reference
#
# remove_reference(:products, :supplier, polymorphic: true)
#
# ====== Remove the reference with a foreign key
#
# remove_reference(:products, :user, foreign_key: true)
#
def remove_reference(table_name, ref_name, foreign_key: false, polymorphic: false, **options)
conditional_options = options.slice(:if_exists, :if_not_exists)
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.merge(conditional_options)
else
foreign_key_options = { to_table: reference_name, **conditional_options }
end
foreign_key_options[:column] ||= "#{ref_name}_id"
remove_foreign_key(table_name, **foreign_key_options)
end
remove_column(table_name, "#{ref_name}_id", **conditional_options)
remove_column(table_name, "#{ref_name}_type", **conditional_options) 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: <tt>fk_rails_<identifier></tt>.
# +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 <tt>:name</tt> 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, ignoring method call if the foreign key exists
#
# add_foreign_key(:articles, :authors, if_not_exists: true)
#
# ====== 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 composite foreign key
#
# Assuming "carts" table has "(shop_id, user_id)" as a primary key.
#
# add_foreign_key :orders, :carts, primary_key: [:shop_id, :user_id]
#
# generates:
#
# ALTER TABLE "orders" ADD CONSTRAINT fk_rails_6f5e4cb3a4 FOREIGN KEY ("cart_shop_id", "cart_user_id") REFERENCES "carts" ("shop_id", "user_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:
# [<tt>:column</tt>]
# The foreign key column name on +from_table+. Defaults to <tt>to_table.singularize + "_id"</tt>.
# Pass an array to create a composite foreign key.
# [<tt>:primary_key</tt>]
# The primary key column name on +to_table+. Defaults to +id+.
# Pass an array to create a composite foreign key.
# [<tt>:name</tt>]
# The constraint name. Defaults to <tt>fk_rails_<identifier></tt>.
# [<tt>:on_delete</tt>]
# Action that happens <tt>ON DELETE</tt>. Valid values are +:nullify+, +:cascade+, and +:restrict+
# [<tt>:on_update</tt>]
# Action that happens <tt>ON UPDATE</tt>. Valid values are +:nullify+, +:cascade+, and +:restrict+
# [<tt>:if_not_exists</tt>]
# Specifies if the foreign key already exists to not try to re-add it. This will avoid
# duplicate column errors.
# [<tt>:validate</tt>]
# (PostgreSQL only) Specify whether or not the constraint should be validated. Defaults to +true+.
# [<tt>:deferrable</tt>]
# (PostgreSQL only) Specify whether or not the foreign key should be deferrable. Valid values are booleans or
# +:deferred+ or +:immediate+ to specify the default behavior. Defaults to +false+.
def add_foreign_key(from_table, to_table, **options)
return unless use_foreign_keys?
return if options[:if_not_exists] == true && foreign_key_exists?(from_table, to_table, **options.slice(:column))
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 on +accounts.owner_id+.
#
# remove_foreign_key :accounts, to_table: :owners
#
# Removes the foreign key named +special_fk_name+ on the +accounts+ table.
#
# remove_foreign_key :accounts, name: :special_fk_name
#
# Checks if the foreign key exists before trying to remove it. Will silently ignore indexes that
# don't exist.
#
# remove_foreign_key :accounts, :branches, if_exists: true
#
# The +options+ hash accepts the same keys as SchemaStatements#add_foreign_key
# with an addition of
# [<tt>:to_table</tt>]
# The name of the table that contains the referenced primary key.
def remove_foreign_key(from_table, to_table = nil, **options)
return unless use_foreign_keys?
return if options.delete(:if_exists) == true && !foreign_key_exists?(from_table, to_table)
fk_name_to_delete = foreign_key_for!(from_table, to_table: to_table, **options).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, to_table = nil, **options)
foreign_key_for(from_table, to_table: to_table, **options).present?
end
def foreign_key_column_for(table_name, column_name) # :nodoc:
name = strip_table_name_prefix_and_suffix(table_name)
"#{name.singularize}_#{column_name}"
end
def foreign_key_options(from_table, to_table, options) # :nodoc:
options = options.dup
if options[:primary_key].is_a?(Array)
options[:column] ||= options[:primary_key].map do |pk_column|
foreign_key_column_for(to_table, pk_column)
end
else
options[:column] ||= foreign_key_column_for(to_table, "id")
end
options[:name] ||= foreign_key_name(from_table, options)
if options[:column].is_a?(Array) || options[:primary_key].is_a?(Array)
if Array(options[:primary_key]).size != Array(options[:column]).size
raise ArgumentError, <<~MSG.squish
For composite primary keys, specify :column and :primary_key, where
:column must reference all the :primary_key columns from #{to_table.inspect}
MSG
end
end
options
end
# Returns an array of check constraints for the given table.
# The check constraints are represented as CheckConstraintDefinition objects.
def check_constraints(table_name)
raise NotImplementedError
end
# Adds a new check constraint to the table. +expression+ is a String
# representation of verifiable boolean condition.
#
# add_check_constraint :products, "price > 0", name: "price_check"
#
# generates:
#
# ALTER TABLE "products" ADD CONSTRAINT price_check CHECK (price > 0)
#
# The +options+ hash can include the following keys:
# [<tt>:name</tt>]
# The constraint name. Defaults to <tt>chk_rails_<identifier></tt>.
# [<tt>:if_not_exists</tt>]
# Silently ignore if the constraint already exists, rather than raise an error.
# [<tt>:validate</tt>]
# (PostgreSQL only) Specify whether or not the constraint should be validated. Defaults to +true+.
def add_check_constraint(table_name, expression, if_not_exists: false, **options)
return unless supports_check_constraints?
options = check_constraint_options(table_name, expression, options)
return if if_not_exists && check_constraint_exists?(table_name, **options)
at = create_alter_table(table_name)
at.add_check_constraint(expression, options)
execute schema_creation.accept(at)
end
def check_constraint_options(table_name, expression, options) # :nodoc:
options = options.dup
options[:name] ||= check_constraint_name(table_name, expression: expression, **options)
options
end
# Removes the given check constraint from the table. Removing a check constraint
# that does not exist will raise an error.
#
# remove_check_constraint :products, name: "price_check"
#
# To silently ignore a non-existent check constraint rather than raise an error,
# use the +if_exists+ option.
#
# remove_check_constraint :products, name: "price_check", if_exists: true
#
# The +expression+ parameter will be ignored if present. It can be helpful
# to provide this in a migration's +change+ method so it can be reverted.
# In that case, +expression+ will be used by #add_check_constraint.
def remove_check_constraint(table_name, expression = nil, if_exists: false, **options)
return unless supports_check_constraints?
return if if_exists && !check_constraint_exists?(table_name, **options)
chk_name_to_delete = check_constraint_for!(table_name, expression: expression, **options).name
at = create_alter_table(table_name)
at.drop_check_constraint(chk_name_to_delete)
execute schema_creation.accept(at)
end
# Checks to see if a check constraint exists on a table for a given check constraint definition.
#
# check_constraint_exists?(:products, name: "price_check")
#
def check_constraint_exists?(table_name, **options)
if !options.key?(:name) && !options.key?(:expression)
raise ArgumentError, "At least one of :name or :expression must be supplied"
end
check_constraint_for(table_name, **options).present?
end
def dump_schema_information # :nodoc:
versions = pool.schema_migration.versions
insert_versions_sql(versions) if versions.any?
end
def internal_string_options_for_primary_key # :nodoc:
{ primary_key: true }
end
def assume_migrated_upto_version(version)
version = version.to_i
sm_table = quote_table_name(pool.schema_migration.table_name)
migration_context = pool.migration_context
migrated = migration_context.get_all_versions
versions = migration_context.migrations.map(&:version)
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
execute insert_versions_sql(inserting)
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 ArgumentError, "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
def distinct_relation_for_primary_key(relation) # :nodoc:
primary_key_columns = Array(relation.primary_key).map do |column|
visitor.compile(relation.table[column])
end
values = columns_for_distinct(
primary_key_columns,
relation.order_values
)
limited = relation.reselect(values).distinct!
limited_ids = select_rows(limited.arel, "SQL").map do |results|
results.last(Array(relation.primary_key).length) # ignores order values for MySQL and PostgreSQL
end
if limited_ids.empty?
relation.none!
else
relation.where!(**Array(relation.primary_key).zip(limited_ids.transpose).to_h)
end
relation.limit_value = relation.offset_value = nil
relation
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)
fragments = add_timestamps_for_alter(table_name, **options)
execute "ALTER TABLE #{quote_table_name(table_name)} #{fragments.join(', ')}"
end
# Removes the timestamp columns (+created_at+ and +updated_at+) from the table definition.
#
# remove_timestamps(:suppliers)
#
def remove_timestamps(table_name, **options)
remove_columns table_name, :updated_at, :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, name: nil, if_not_exists: false, internal: false, **options) # :nodoc:
options.assert_valid_keys(:unique, :length, :order, :opclass, :where, :type, :using, :comment, :algorithm, :include, :nulls_not_distinct)
column_names = index_column_names(column_name)
index_name = name&.to_s
index_name ||= index_name(table_name, column_names)
validate_index_length!(table_name, index_name, internal)
index = IndexDefinition.new(
table_name, index_name,
options[:unique],
column_names,
lengths: options[:length] || {},
orders: options[:order] || {},
opclasses: options[:opclass] || {},
where: options[:where],
type: options[:type],
using: options[:using],
include: options[:include],
nulls_not_distinct: options[:nulls_not_distinct],
comment: options[:comment]
)
[index, index_algorithm(options[:algorithm]), if_not_exists]
end
def index_algorithm(algorithm) # :nodoc:
index_algorithms.fetch(algorithm) do
raise ArgumentError, "Algorithm must be one of the following: #{index_algorithms.keys.map(&:inspect).join(', ')}"
end if algorithm
end
def quoted_columns_for_index(column_names, options) # :nodoc:
quoted_columns = column_names.each_with_object({}) do |name, result|
result[name.to_sym] = quote_column_name(name).dup
end
add_options_for_index_columns(quoted_columns, **options).values.join(", ")
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+.
#
# Passing a hash containing +:from+ and +:to+ will make this change
# reversible in migration:
#
# change_table_comment(:posts, from: "old_comment", to: "new_comment")
def change_table_comment(table_name, comment_or_changes)
raise NotImplementedError, "#{self.class} does not support changing table comments"
end
# Changes the comment for a column or removes it if +nil+.
#
# Passing a hash containing +:from+ and +:to+ will make this change
# reversible in migration:
#
# change_column_comment(:posts, :state, from: "old_comment", to: "new_comment")
def change_column_comment(table_name, column_name, comment_or_changes)
raise NotImplementedError, "#{self.class} does not support changing column comments"
end
def create_schema_dumper(options) # :nodoc:
SchemaDumper.create(self, options)
end
def use_foreign_keys?
supports_foreign_keys? && foreign_keys_enabled?
end
# Returns an instance of SchemaCreation, which can be used to visit a schema definition
# object and return DDL.
def schema_creation # :nodoc:
SchemaCreation.new(self)
end
def bulk_change_table(table_name, operations) # :nodoc:
sql_fragments = []
non_combinable_operations = []
operations.each do |command, args|
table, arguments = args.shift, args
method = :"#{command}_for_alter"
if respond_to?(method, true)
sqls, procs = Array(send(method, table, *arguments)).partition { |v| v.is_a?(String) }
sql_fragments.concat(sqls)
non_combinable_operations.concat(procs)
else
execute "ALTER TABLE #{quote_table_name(table_name)} #{sql_fragments.join(", ")}" unless sql_fragments.empty?
non_combinable_operations.each(&:call)
sql_fragments = []
non_combinable_operations = []
send(command, table, *arguments)
end
end
execute "ALTER TABLE #{quote_table_name(table_name)} #{sql_fragments.join(", ")}" unless sql_fragments.empty?
non_combinable_operations.each(&:call)
end
def valid_table_definition_options # :nodoc:
[:temporary, :if_not_exists, :options, :as, :comment, :charset, :collation]
end
def valid_column_definition_options # :nodoc:
ColumnDefinition::OPTION_NAMES
end
def valid_primary_key_options # :nodoc:
[:limit, :default, :precision]
end
# Returns the maximum length of an index name in bytes.
def max_index_name_size
62
end
private
def generate_index_name(table_name, column)
name = "index_#{table_name}_on_#{Array(column) * '_and_'}"
return name if name.bytesize <= max_index_name_size
# Fallback to short version, add hash to ensure uniqueness
hashed_identifier = "_" + OpenSSL::Digest::SHA256.hexdigest(name).first(10)
name = "idx_on_#{Array(column) * '_'}"
short_limit = max_index_name_size - hashed_identifier.bytesize
short_name = name.mb_chars.limit(short_limit).to_s
"#{short_name}#{hashed_identifier}"
end
def validate_change_column_null_argument!(value)
unless value == true || value == false
raise ArgumentError, "change_column_null expects a boolean value (true for NULL, false for NOT NULL). Got: #{value.inspect}"
end
end
def column_options_keys
[:limit, :precision, :scale, :default, :null, :collation, :comment]
end
def add_index_sort_order(quoted_columns, **options)
orders = options_for_index_columns(options[:order])
quoted_columns.each do |name, column|
column << " #{orders[name].upcase}" if orders[name].present?
end
end
def options_for_index_columns(options)
if options.is_a?(Hash)
options.symbolize_keys
else
Hash.new { |hash, column| hash[column] = options }
end
end
# Overridden by the MySQL adapter for supporting index lengths and by
# the PostgreSQL adapter for supporting operator classes.
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 index_name_for_remove(table_name, column_name, options)
return options[:name] if can_remove_index_by_name?(column_name, options)
checks = []
if !options.key?(:name) && expression_column_name?(column_name)
options[:name] = index_name(table_name, column_name)
column_names = []
else
column_names = index_column_names(column_name || options[:column])
end
checks << lambda { |i| i.name == options[:name].to_s } if options.key?(:name)
if column_names.present? && !(options.key?(:name) && expression_column_name?(column_names))
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(name, **options)
TableDefinition.new(self, name, **options)
end
def create_alter_table(name)
AlterTable.new create_table_definition(name)
end
def validate_create_table_options!(options)
unless options[:_skip_validate_options]
options
.except(:_uses_legacy_table_name, :_skip_validate_options)
.assert_valid_keys(valid_table_definition_options, valid_primary_key_options)
end
end
def fetch_type_metadata(sql_type)
cast_type = lookup_cast_type(sql_type)
SqlTypeMetadata.new(
sql_type: sql_type,
type: cast_type.type,
limit: cast_type.limit,
precision: cast_type.precision,
scale: cast_type.scale,
)
end
def index_column_names(column_names)
if expression_column_name?(column_names)
column_names
else
Array(column_names)
end
end
def index_name_options(column_names)
if expression_column_name?(column_names)
column_names = column_names.scan(/\w+/).join("_")
end
{ column: column_names }
end
# Try to identify whether the given column name is an expression
def expression_column_name?(column_name)
column_name.is_a?(String) && /\W/.match?(column_name)
end
def strip_table_name_prefix_and_suffix(table_name)
prefix = Base.table_name_prefix
suffix = Base.table_name_suffix
table_name.to_s =~ /#{prefix}(.+)#{suffix}/ ? $1 : table_name.to_s
end
def foreign_key_name(table_name, options)
options.fetch(:name) do
columns = Array(options.fetch(:column)).map(&:to_s)
identifier = "#{table_name}_#{columns * '_and_'}_fk"
hashed_identifier = OpenSSL::Digest::SHA256.hexdigest(identifier).first(10)
"fk_rails_#{hashed_identifier}"
end
end
def foreign_key_for(from_table, **options)
return unless use_foreign_keys?
foreign_keys(from_table).detect { |fk| fk.defined_for?(**options) }
end
def foreign_key_for!(from_table, to_table: nil, **options)
foreign_key_for(from_table, to_table: to_table, **options) ||
raise(ArgumentError, "Table '#{from_table}' has no foreign key for #{to_table || options}")
end
def extract_foreign_key_action(specifier)
case specifier
when "CASCADE"; :cascade
when "SET NULL"; :nullify
when "RESTRICT"; :restrict
end
end
def foreign_keys_enabled?
@config.fetch(:foreign_keys, true)
end
def check_constraint_name(table_name, **options)
options.fetch(:name) do
expression = options.fetch(:expression)
identifier = "#{table_name}_#{expression}_chk"
hashed_identifier = OpenSSL::Digest::SHA256.hexdigest(identifier).first(10)
"chk_rails_#{hashed_identifier}"
end
end
def check_constraint_for(table_name, **options)
return unless supports_check_constraints?
chk_name = check_constraint_name(table_name, **options)
check_constraints(table_name).detect { |chk| chk.defined_for?(name: chk_name, **options) }
end
def check_constraint_for!(table_name, expression: nil, **options)
check_constraint_for(table_name, expression: expression, **options) ||
raise(ArgumentError, "Table '#{table_name}' has no check constraint for #{expression || options}")
end
def validate_index_length!(table_name, new_name, internal = false)
if new_name.length > index_name_length
raise ArgumentError, "Index name '#{new_name}' on table '#{table_name}' is too long; the limit is #{index_name_length} characters"
end
end
def validate_table_length!(table_name)
if table_name.length > table_name_length
raise ArgumentError, "Table name '#{table_name}' is too long; the limit is #{table_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
alias :extract_new_comment_value :extract_new_default_value
def can_remove_index_by_name?(column_name, options)
column_name.nil? && options.key?(:name) && options.except(:name, :algorithm).empty?
end
def reference_name_for_table(table_name)
table_name.to_s.singularize
end
def add_column_for_alter(table_name, column_name, type, **options)
td = create_table_definition(table_name)
cd = td.new_column_definition(column_name, type, **options)
schema_creation.accept(AddColumnDefinition.new(cd))
end
def change_column_default_for_alter(table_name, column_name, default_or_changes)
cd = build_change_column_default_definition(table_name, column_name, default_or_changes)
schema_creation.accept(cd)
end
def rename_column_sql(table_name, column_name, new_column_name)
"RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
end
def remove_column_for_alter(table_name, column_name, type = nil, **options)
"DROP COLUMN #{quote_column_name(column_name)}"
end
def remove_columns_for_alter(table_name, *column_names, **options)
column_names.map { |column_name| remove_column_for_alter(table_name, column_name) }
end
def add_timestamps_for_alter(table_name, **options)
options[:null] = false if options[:null].nil?
if !options.key?(:precision) && supports_datetime_with_precision?
options[:precision] = 6
end
[
add_column_for_alter(table_name, :created_at, :datetime, **options),
add_column_for_alter(table_name, :updated_at, :datetime, **options)
]
end
def remove_timestamps_for_alter(table_name, **options)
remove_columns_for_alter(table_name, :updated_at, :created_at)
end
def insert_versions_sql(versions)
sm_table = quote_table_name(pool.schema_migration.table_name)
if versions.is_a?(Array)
sql = +"INSERT INTO #{sm_table} (version) VALUES\n"
sql << versions.reverse.map { |v| "(#{quote(v)})" }.join(",\n")
sql << ";"
sql
else
"INSERT INTO #{sm_table} (version) VALUES (#{quote(versions)});"
end
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