Skip to content
This repository
tree: fa34acec20
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 607 lines (544 sloc) 24.34 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606
require 'active_support/core_ext/array/wrap'
require 'active_support/deprecation/reporting'

module ActiveRecord
  module ConnectionAdapters # :nodoc:
    module SchemaStatements
      # 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].gsub(/\./, '_')
      end

      # Checks to see if the table +table_name+ exists on the database.
      #
      # === Example
      # 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.
      #
      # === Examples
      # # 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.wrap(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, name = nil) end

      # Checks to see if a column exists in a given table.
      #
      # === Examples
      # # 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)
      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[:limit] || c.limit == options[:limit]) &&
                                      (!options[:precision] || c.precision == options[:precision]) &&
                                      (!options[:scale] || c.scale == options[:scale]) }
      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 +has_and_belongs_to_many+ should set it to false.
      # [<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 this option is ignored.
      #
      # Also note that this just sets the primary key in the table. You additionally
      # need to configure the primary key in the model via +self.primary_key=+.
      # Models do NOT auto-detect the primary key from their table 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.
      #
      # ===== Examples
      # ====== 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
      # )
      #
      # See also TableDefinition#column for details on how to create columns.
      def create_table(table_name, options = {})
        td = table_definition
        td.primary_key(options[:primary_key] || Base.get_primary_key(table_name.to_s.singularize)) unless options[:id] == false

        yield td if block_given?

        if options[:force] && table_exists?(table_name)
          drop_table(table_name, options)
        end

        create_sql = "CREATE#{' TEMPORARY' if options[:temporary]} TABLE "
        create_sql << "#{quote_table_name(table_name)} ("
        create_sql << td.to_sql
        create_sql << ") #{options[:options]}"
        execute create_sql
      end

      # A block for changing columns in +table+.
      #
      # === Example
      # # 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(11), ADD COLUMN birthdate DATETIME ...
      #
      # Defaults to false.
      #
      # ===== Examples
      # ====== 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 <tt>company_id(integer)</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(integer)</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 transformation
      def change_table(table_name, options = {})
        if supports_bulk_alter? && options[:bulk]
          recorder = ActiveRecord::Migration::CommandRecorder.new(self)
          yield Table.new(table_name, recorder)
          bulk_change_table(table_name, recorder.commands)
        else
          yield Table.new(table_name, self)
        end
      end

      # Renames a table.
      # ===== Example
      # 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.
      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 = {})
        add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
        add_column_options!(add_column_sql, options)
        execute(add_column_sql)
      end

      # Removes the column(s) from the table definition.
      # ===== Examples
      # remove_column(:suppliers, :qualification)
      # remove_columns(:suppliers, :qualification, :experience)
      def remove_column(table_name, *column_names)
        if column_names.flatten!
          message = 'Passing array to remove_columns is deprecated, please use ' +
                    'multiple arguments, like: `remove_columns(:posts, :foo, :bar)`'
          ActiveSupport::Deprecation.warn message, caller
        end

        columns_for_remove(table_name, *column_names).each do |column_name|
          execute "ALTER TABLE #{quote_table_name(table_name)} DROP #{column_name}"
        end
      end
      alias :remove_columns :remove_column

      # Changes the column's definition according to the new options.
      # See TableDefinition#column for details of the options you can use.
      # ===== Examples
      # 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.
      # ===== Examples
      # change_column_default(:suppliers, :qualification, 'new')
      # change_column_default(:accounts, :authorized, 1)
      # change_column_default(:users, :email, nil)
      def change_column_default(table_name, column_name, default)
        raise NotImplementedError, "change_column_default is not implemented"
      end

      # Renames a column.
      # ===== Example
      # 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.
      #
      # ===== Examples
      #
      # ====== 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, :part_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)
      #
      def add_index(table_name, column_name, options = {})
        index_name, index_type, index_columns = 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})"
      end

      # Remove the given index from the table.
      #
      # Remove the index_accounts_on_column in the accounts table.
      # remove_index :accounts, :column
      # Remove the index named index_accounts_on_branch_id in the accounts table.
      # remove_index :accounts, :column => :branch_id
      # Remove the index named index_accounts_on_branch_id_and_party_id in the accounts table.
      # remove_index :accounts, :column => [:branch_id, :party_id]
      # Remove 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

      # Rename 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
        remove_index(table_name, :name => old_name)
        add_index(table_name, old_index_def.columns, :name => new_name, :unique => old_index_def.unique)
      end

      def index_name(table_name, options) #:nodoc:
        if Hash === options # legacy support
          if options[:column]
            "index_#{table_name}_on_#{Array.wrap(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

      # Verify 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

      # Returns a string of <tt>CREATE TABLE</tt> SQL statement(s) for recreating the
      # entire structure of the database.
      def structure_dump
      end

      def dump_schema_information #:nodoc:
        sm_table = ActiveRecord::Migrator.schema_migrations_table_name
        migrated = select_values("SELECT version FROM #{sm_table} ORDER BY version")
        migrated.map { |v| "INSERT INTO #{sm_table} (version) VALUES ('#{v}');" }.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
        sm_table = ActiveRecord::Migrator.schema_migrations_table_name

        unless table_exists?(sm_table)
          create_table(sm_table, :id => false) do |schema_migrations_table|
            schema_migrations_table.column :version, :string, :null => false
          end
          add_index sm_table, :version, :unique => true,
            :name => "#{Base.table_name_prefix}unique_schema_migrations#{Base.table_name_suffix}"

          # Backwards-compatibility: if we find schema_info, assume we've
          # migrated up to that point:
          si_table = Base.table_name_prefix + 'schema_info' + Base.table_name_suffix

          if table_exists?(si_table)
            ActiveSupport::Deprecation.warn "Usage of the schema table `#{si_table}` is deprecated. Please switch to using `schema_migrations` table"

            old_version = select_value("SELECT version FROM #{quote_table_name(si_table)}").to_i
            assume_migrated_upto_version(old_version)
            drop_table(si_table)
          end
        end
      end

      def assume_migrated_upto_version(version, migrations_paths = ActiveRecord::Migrator.migrations_paths)
        migrations_paths = Array.wrap(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 if specified"
            end

          elsif (type != :primary_key) && (limit ||= native.is_a?(Hash) && native[:limit])
            column_type_sql << "(#{limit})"
          end

          column_type_sql
        else
          type
        end
      end

      def add_column_options!(sql, options) #:nodoc:
        sql << " DEFAULT #{quote(options[:default], options[:column])}" if options_include_default?(options)
        # must explicitly check for :null to allow change_column to work on migrations
        if options[:null] == false
          sql << " NOT NULL"
        end
      end

      # SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.
      # Both PostgreSQL and Oracle overrides this for custom DISTINCT syntax.
      #
      # distinct("posts.id", "posts.created_at desc")
      def distinct(columns, order_by)
        "DISTINCT #{columns}"
      end

      # Adds timestamps (created_at and updated_at) columns to the named table.
      # ===== Examples
      # add_timestamps(:suppliers)
      def add_timestamps(table_name)
        add_column table_name, :created_at, :datetime
        add_column table_name, :updated_at, :datetime
      end

      # Removes the timestamp columns (created_at and updated_at) from the table definition.
      # ===== Examples
      # remove_timestamps(:suppliers)
      def remove_timestamps(table_name)
        remove_column table_name, :updated_at
        remove_column table_name, :created_at
      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].to_s.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.wrap(column_name)
          index_name = index_name(table_name, :column => column_names)

          if Hash === options # legacy support, since this param was a string
            index_type = options[:unique] ? "UNIQUE" : ""
            index_name = options[:name].to_s if options.key?(:name)
          else
            index_type = options
          end

          if index_name.length > index_name_length
            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' is too long; the limit is #{index_name_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]
        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)
            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"
          end

          index_name
        end

        def columns_for_remove(table_name, *column_names)
          column_names = column_names.flatten

          raise ArgumentError.new("You must specify at least one column name. Example: remove_column(:people, :first_name)") if column_names.blank?
          column_names.map {|column_name| quote_column_name(column_name) }
        end

      private
      def table_definition
        TableDefinition.new(self)
      end
    end
  end
end
Something went wrong with that request. Please try again.