require 'active_record/migration/join_table' 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 # 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 # Checks to see if the table +table_name+ exists on the database. # # table_exists?(:developers) # def table_exists?(table_name) tables.include?(table_name.to_s) end # Returns an array of indexes for the given table. # def indexes(table_name, name = nil) 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) index_name = options.key?(:name) ? options[:name].to_s : index_name(table_name, :column => column_names) if options[:unique] indexes(table_name).any?{ |i| i.unique && i.name == index_name } else indexes(table_name).any?{ |i| i.name == index_name } end 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) 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 = {}) columns(table_name).any?{ |c| c.name == column_name.to_s && (!type || c.type == type) && (!options.key?(:limit) || c.limit == options[:limit]) && (!options.key?(:precision) || c.precision == options[:precision]) && (!options.key?(:scale) || c.scale == options[:scale]) && (!options.key?(:default) || c.default == options[:default]) && (!options.key?(:null) || c.null == options[:null]) } 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 +has_and_belongs_to_many+ should set it to false. # [:primary_key] # The name of the primary key, if one is to be added automatically. # Defaults to +id+. If :id is false this option is ignored. # # Note that Active Record models will automatically detect their # primary key. This can be avoided by using +self.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. # 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(11) DEFAULT NULL 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(11) DEFAULT NULL auto_increment PRIMARY KEY, # name varchar(80) # ) # # ====== 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, options = {}) td = create_table_definition table_name, options[:temporary], options[:options], options[:as] if !options[:as] unless options[:id] == false pk = options.fetch(:primary_key) { Base.get_primary_key table_name.to_s.singularize } td.primary_key pk, options.fetch(:id, :primary_key), options end yield td if block_given? end if options[:force] && table_exists?(table_name) drop_table(table_name, options) end execute schema_creation.accept td td.indexes.each_pair { |c,o| add_index table_name, c, o } 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 a +options+ hash 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, options = {}) join_table_name = find_join_table_name(table_1, table_2, options) column_options = options.delete(:column_options) || {} column_options.reverse_merge!(null: false) t1_column, t2_column = [table_1, table_2].map{ |t| t.to_s.singularize.foreign_key } create_table(join_table_name, options.merge!(id: false)) do |td| td.integer t1_column, column_options td.integer t2_column, 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(11), 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 transformation. 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. # # Although this command ignores +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 #{quote_table_name(table_name)}" end # Adds a new column to the named table. # See TableDefinition#column for details of the options you can use. 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) # def change_column_default(table_name, column_name, default) 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 # +NULL+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 :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)) # # 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 # # ====== 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. Supported: :fulltext and :spatial on MyISAM tables. 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_accounts_on_column+ in the +accounts+ table. # # remove_index :accounts, :column # # Removes the index named +index_accounts_on_branch_id+ in the +accounts+ table. # # remove_index :accounts, column: :branch_id # # Removes the index named +index_accounts_on_branch_id_and_party_id+ in the +accounts+ table. # # 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 = {}) remove_index!(table_name, index_name_for_remove(table_name, options)) end def remove_index!(table_name, index_name) #:nodoc: 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) # 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, :column => options) end end # Verifies the existence of an index with a given name. # # The default argument is returned if the underlying implementation does not define the indexes method, # as there's no way to determine the correct answer in that case. def index_name_exists?(table_name, index_name, default) return default unless respond_to?(:indexes) index_name = index_name.to_s indexes(table_name).detect { |i| i.name == index_name } end # Adds a reference. Optionally adds a +type+ column, if :polymorphic option is provided. # add_reference and add_belongs_to are acceptable. # # ====== Create a user_id column # # add_reference(:products, :user) # # ====== Create a supplier_id and supplier_type columns # # add_belongs_to(:products, :supplier, polymorphic: true) # # ====== Create a supplier_id, supplier_type columns and appropriate index # # add_reference(:products, :supplier, polymorphic: true, index: true) # def add_reference(table_name, ref_name, options = {}) polymorphic = options.delete(:polymorphic) index_options = options.delete(:index) add_column(table_name, "#{ref_name}_id", :integer, options) add_column(table_name, "#{ref_name}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic add_index(table_name, polymorphic ? %w[id type].map{ |t| "#{ref_name}_#{t}" } : "#{ref_name}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options end alias :add_belongs_to :add_reference # Removes the reference(s). Also removes a +type+ column if one exists. # remove_reference, remove_references and remove_belongs_to are acceptable. # # ====== Remove the reference # # remove_reference(:products, :user, index: true) # # ====== Remove polymorphic reference # # remove_reference(:products, :supplier, polymorphic: true) # def remove_reference(table_name, ref_name, options = {}) remove_column(table_name, "#{ref_name}_id") remove_column(table_name, "#{ref_name}_type") if options[:polymorphic] end alias :remove_belongs_to :remove_reference def dump_schema_information #:nodoc: sm_table = ActiveRecord::Migrator.schema_migrations_table_name ActiveRecord::SchemaMigration.order('version').map { |sm| "INSERT INTO #{sm_table} (version) VALUES ('#{sm.version}');" }.join "\n\n" end # Should not be called normally, but this operation is non-destructive. # The migrations module handles this automatically. def initialize_schema_migrations_table ActiveRecord::SchemaMigration.create_table end def assume_migrated_upto_version(version, migrations_paths = ActiveRecord::Migrator.migrations_paths) migrations_paths = Array(migrations_paths) version = version.to_i sm_table = quote_table_name(ActiveRecord::Migrator.schema_migrations_table_name) migrated = select_values("SELECT version FROM #{sm_table}").map { |v| v.to_i } paths = migrations_paths.map {|p| "#{p}/[0-9]*_*.rb" } versions = Dir[*paths].map do |filename| filename.split('/').last.split('_').first.to_i end unless migrated.include?(version) execute "INSERT INTO #{sm_table} (version) VALUES ('#{version}')" end inserted = Set.new (versions - migrated).each do |v| if inserted.include?(v) raise "Duplicate migration #{v}. Please renumber your migrations to resolve the conflict." elsif v < version execute "INSERT INTO #{sm_table} (version) VALUES ('#{v}')" inserted << v end end end def type_to_sql(type, limit = nil, precision = nil, scale = nil) #:nodoc: if native = native_database_types[type.to_sym] 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 (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. # Both PostgreSQL and Oracle overrides 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 the named table. # # add_timestamps(:suppliers) # def add_timestamps(table_name, options = {}) 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) 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 protected def add_index_sort_order(option_strings, column_names, options = {}) if options.is_a?(Hash) && order = options[:order] case order when Hash column_names.each {|name| option_strings[name] += " #{order[name].upcase}" if order.has_key?(name)} when String column_names.each {|name| option_strings[name] += " #{order.upcase}"} end end return option_strings end # Overridden by the mysql adapter for supporting index lengths def quoted_columns_for_index(column_names, options = {}) option_strings = Hash[column_names.map {|name| [name, '']}] # add index sort order if supported if supports_index_sort_order? option_strings = add_index_sort_order(option_strings, column_names, options) end column_names.map {|name| quote_column_name(name) + option_strings[name]} end def options_include_default?(options) options.include?(:default) && !(options[:null] == false && options[:default].nil?) end def add_index_options(table_name, column_name, options = {}) column_names = Array(column_name) index_name = index_name(table_name, column: column_names) options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm, :type) index_type = options[:unique] ? "UNIQUE" : "" index_type = options[:type].to_s if options.key?(:type) index_name = options[:name].to_s if options.key?(:name) max_index_length = options.fetch(:internal, false) ? index_name_length : allowed_index_name_length 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 if index_name.length > max_index_length raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' is too long; the limit is #{max_index_length} characters" end if index_name_exists?(table_name, index_name, false) 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] end def index_name_for_remove(table_name, options = {}) index_name = index_name(table_name, options) unless index_name_exists?(table_name, index_name, true) if options.is_a?(Hash) && options.has_key?(:name) options_without_column = options.dup options_without_column.delete :column index_name_without_column = index_name(table_name, options_without_column) return index_name_without_column if index_name_exists?(table_name, index_name_without_column, false) end raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist" end index_name 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 private def create_table_definition(name, temporary, options, as = nil) TableDefinition.new native_database_types, name, temporary, options, as end def create_alter_table(name) AlterTable.new create_table_definition(name, false, {}) end end end end