vendor/rails/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb

   1 require 'active_record/connection_adapters/abstract_adapter'
   2
   3 module ActiveRecord
   4   class Base
   5     class << self
   6       # Establishes a connection to the database that's used by all Active Record objects
   7       def sqlite_connection(config) # :nodoc:
   8         parse_sqlite_config!(config)
   9
  10         unless self.class.const_defined?(:SQLite)
  11           require_library_or_gem(config[:adapter])
  12
  13           db = SQLite::Database.new(config[:database], 0)
  14           db.show_datatypes   = "ON" if !defined? SQLite::Version
  15           db.results_as_hash  = true if defined? SQLite::Version
  16           db.type_translation = false
  17
  18           # "Downgrade" deprecated sqlite API
  19           if SQLite.const_defined?(:Version)
  20             ConnectionAdapters::SQLite2Adapter.new(db, logger, config)
  21           else
  22             ConnectionAdapters::DeprecatedSQLiteAdapter.new(db, logger, config)
  23           end
  24         end
  25       end
  26
  27       private
  28         def parse_sqlite_config!(config)
  29           config[:database] ||= config[:dbfile]
  30           # Require database.
  31           unless config[:database]
  32             raise ArgumentError, "No database file specified. Missing argument: database"
  33           end
  34
  35           # Allow database path relative to RAILS_ROOT, but only if
  36           # the database path is not the special path that tells
  37           # Sqlite to build a database only in memory.
  38           if Object.const_defined?(:RAILS_ROOT) && ':memory:' != config[:database]
  39             config[:database] = File.expand_path(config[:database], RAILS_ROOT)
  40           end
  41         end
  42     end
  43   end
  44
  45   module ConnectionAdapters #:nodoc:
  46     class SQLiteColumn < Column #:nodoc:
  47       class <<  self
  48         def string_to_binary(value)
  49           value.gsub(/\0|\%/n) do |b|
  50             case b
  51               when "\0" then "%00"
  52               when "%"  then "%25"
  53             end
  54           end
  55         end
  56
  57         def binary_to_string(value)
  58           value.gsub(/%00|%25/n) do |b|
  59             case b
  60               when "%00" then "\0"
  61               when "%25" then "%"
  62             end
  63           end
  64         end
  65       end
  66     end
  67
  68     # The SQLite adapter works with both the 2.x and 3.x series of SQLite with the sqlite-ruby drivers (available both as gems and
  69     # from http://rubyforge.org/projects/sqlite-ruby/).
  70     #
  71     # Options:
  72     #
  73     # * <tt>:database</tt> - Path to the database file.
  74     class SQLiteAdapter < AbstractAdapter
  75       class Version
  76         include Comparable
  77
  78         def initialize(version_string)
  79           @version = version_string.split('.').map(&:to_i)
  80         end
  81
  82         def <=>(version_string)
  83           @version <=> version_string.split('.').map(&:to_i)
  84         end
  85       end
  86
  87       def initialize(connection, logger, config)
  88         super(connection, logger)
  89         @config = config
  90       end
  91
  92       def adapter_name #:nodoc:
  93         'SQLite'
  94       end
  95
  96       def supports_ddl_transactions?
  97         sqlite_version >= '2.0.0'
  98       end
  99
 100       def supports_migrations? #:nodoc:
 101         true
 102       end
 103
 104       def requires_reloading?
 105         true
 106       end
 107
 108       def supports_add_column?
 109         sqlite_version >= '3.1.6'
 110       end
 111
 112       def disconnect!
 113         super
 114         @connection.close rescue nil
 115       end
 116
 117       def supports_count_distinct? #:nodoc:
 118         sqlite_version >= '3.2.6'
 119       end
 120
 121       def supports_autoincrement? #:nodoc:
 122         sqlite_version >= '3.1.0'
 123       end
 124
 125       def native_database_types #:nodoc:
 126         {
 127           :primary_key => default_primary_key_type,
 128           :string      => { :name => "varchar", :limit => 255 },
 129           :text        => { :name => "text" },
 130           :integer     => { :name => "integer" },
 131           :float       => { :name => "float" },
 132           :decimal     => { :name => "decimal" },
 133           :datetime    => { :name => "datetime" },
 134           :timestamp   => { :name => "datetime" },
 135           :time        => { :name => "time" },
 136           :date        => { :name => "date" },
 137           :binary      => { :name => "blob" },
 138           :boolean     => { :name => "boolean" }
 139         }
 140       end
 141
 142
 143       # QUOTING ==================================================
 144
 145       def quote_string(s) #:nodoc:
 146         @connection.class.quote(s)
 147       end
 148
 149       def quote_column_name(name) #:nodoc:
 150         %Q("#{name}")
 151       end
 152
 153
 154       # DATABASE STATEMENTS ======================================
 155
 156       def execute(sql, name = nil) #:nodoc:
 157         catch_schema_changes { log(sql, name) { @connection.execute(sql) } }
 158       end
 159
 160       def update_sql(sql, name = nil) #:nodoc:
 161         super
 162         @connection.changes
 163       end
 164
 165       def delete_sql(sql, name = nil) #:nodoc:
 166         sql += " WHERE 1=1" unless sql =~ /WHERE/i
 167         super sql, name
 168       end
 169
 170       def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
 171         super || @connection.last_insert_row_id
 172       end
 173
 174       def select_rows(sql, name = nil)
 175         execute(sql, name).map do |row|
 176           (0...(row.size / 2)).map { |i| row[i] }
 177         end
 178       end
 179
 180       def begin_db_transaction #:nodoc:
 181         catch_schema_changes { @connection.transaction }
 182       end
 183
 184       def commit_db_transaction #:nodoc:
 185         catch_schema_changes { @connection.commit }
 186       end
 187
 188       def rollback_db_transaction #:nodoc:
 189         catch_schema_changes { @connection.rollback }
 190       end
 191
 192       # SELECT ... FOR UPDATE is redundant since the table is locked.
 193       def add_lock!(sql, options) #:nodoc:
 194         sql
 195       end
 196
 197
 198       # SCHEMA STATEMENTS ========================================
 199
 200       def tables(name = nil) #:nodoc:
 201         sql = <<-SQL
 202           SELECT name
 203           FROM sqlite_master
 204           WHERE type = 'table' AND NOT name = 'sqlite_sequence'
 205         SQL
 206
 207         execute(sql, name).map do |row|
 208           row[0]
 209         end
 210       end
 211
 212       def columns(table_name, name = nil) #:nodoc:
 213         table_structure(table_name).map do |field|
 214           SQLiteColumn.new(field['name'], field['dflt_value'], field['type'], field['notnull'] == "0")
 215         end
 216       end
 217
 218       def indexes(table_name, name = nil) #:nodoc:
 219         execute("PRAGMA index_list(#{quote_table_name(table_name)})", name).map do |row|
 220           index = IndexDefinition.new(table_name, row['name'])
 221           index.unique = row['unique'] != '0'
 222           index.columns = execute("PRAGMA index_info('#{index.name}')").map { |col| col['name'] }
 223           index
 224         end
 225       end
 226
 227       def primary_key(table_name) #:nodoc:
 228         column = table_structure(table_name).find {|field| field['pk'].to_i == 1}
 229         column ? column['name'] : nil
 230       end
 231
 232       def remove_index(table_name, options={}) #:nodoc:
 233         execute "DROP INDEX #{quote_column_name(index_name(table_name, options))}"
 234       end
 235
 236       def rename_table(name, new_name)
 237         execute "ALTER TABLE #{name} RENAME TO #{new_name}"
 238       end
 239
 240       # See: http://www.sqlite.org/lang_altertable.html
 241       # SQLite has an additional restriction on the ALTER TABLE statement
 242       def valid_alter_table_options( type, options)
 243         type.to_sym != :primary_key
 244       end
 245
 246       def add_column(table_name, column_name, type, options = {}) #:nodoc:
 247         if supports_add_column? && valid_alter_table_options( type, options )
 248           super(table_name, column_name, type, options)
 249         else
 250           alter_table(table_name) do |definition|
 251             definition.column(column_name, type, options)
 252           end
 253         end
 254       end
 255
 256       def remove_column(table_name, *column_names) #:nodoc:
 257         column_names.flatten.each do |column_name|
 258           alter_table(table_name) do |definition|
 259             definition.columns.delete(definition[column_name])
 260           end
 261         end
 262       end
 263       alias :remove_columns :remove_column
 264
 265       def change_column_default(table_name, column_name, default) #:nodoc:
 266         alter_table(table_name) do |definition|
 267           definition[column_name].default = default
 268         end
 269       end
 270
 271       def change_column_null(table_name, column_name, null, default = nil)
 272         unless null || default.nil?
 273           execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
 274         end
 275         alter_table(table_name) do |definition|
 276           definition[column_name].null = null
 277         end
 278       end
 279
 280       def change_column(table_name, column_name, type, options = {}) #:nodoc:
 281         alter_table(table_name) do |definition|
 282           include_default = options_include_default?(options)
 283           definition[column_name].instance_eval do
 284             self.type    = type
 285             self.limit   = options[:limit] if options.include?(:limit)
 286             self.default = options[:default] if include_default
 287             self.null    = options[:null] if options.include?(:null)
 288           end
 289         end
 290       end
 291
 292       def rename_column(table_name, column_name, new_column_name) #:nodoc:
 293         unless columns(table_name).detect{|c| c.name == column_name.to_s }
 294           raise ActiveRecord::ActiveRecordError, "Missing column #{table_name}.#{column_name}"
 295         end
 296         alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
 297       end
 298
 299       def empty_insert_statement(table_name)
 300         "INSERT INTO #{table_name} VALUES(NULL)"
 301       end
 302
 303       protected
 304         def select(sql, name = nil) #:nodoc:
 305           execute(sql, name).map do |row|
 306             record = {}
 307             row.each_key do |key|
 308               if key.is_a?(String)
 309                 record[key.sub(/^"?\w+"?\./, '')] = row[key]
 310               end
 311             end
 312             record
 313           end
 314         end
 315
 316         def table_structure(table_name)
 317           returning structure = execute("PRAGMA table_info(#{quote_table_name(table_name)})") do
 318             raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
 319           end
 320         end
 321
 322         def alter_table(table_name, options = {}) #:nodoc:
 323           altered_table_name = "altered_#{table_name}"
 324           caller = lambda {|definition| yield definition if block_given?}
 325
 326           transaction do
 327             move_table(table_name, altered_table_name,
 328               options.merge(:temporary => true))
 329             move_table(altered_table_name, table_name, &caller)
 330           end
 331         end
 332
 333         def move_table(from, to, options = {}, &block) #:nodoc:
 334           copy_table(from, to, options, &block)
 335           drop_table(from)
 336         end
 337
 338         def copy_table(from, to, options = {}) #:nodoc:
 339           options = options.merge(:id => (!columns(from).detect{|c| c.name == 'id'}.nil? && 'id' == primary_key(from).to_s))
 340           create_table(to, options) do |definition|
 341             @definition = definition
 342             columns(from).each do |column|
 343               column_name = options[:rename] ?
 344                 (options[:rename][column.name] ||
 345                  options[:rename][column.name.to_sym] ||
 346                  column.name) : column.name
 347
 348               @definition.column(column_name, column.type,
 349                 :limit => column.limit, :default => column.default,
 350                 :null => column.null)
 351             end
 352             @definition.primary_key(primary_key(from)) if primary_key(from)
 353             yield @definition if block_given?
 354           end
 355
 356           copy_table_indexes(from, to, options[:rename] || {})
 357           copy_table_contents(from, to,
 358             @definition.columns.map {|column| column.name},
 359             options[:rename] || {})
 360         end
 361
 362         def copy_table_indexes(from, to, rename = {}) #:nodoc:
 363           indexes(from).each do |index|
 364             name = index.name
 365             if to == "altered_#{from}"
 366               name = "temp_#{name}"
 367             elsif from == "altered_#{to}"
 368               name = name[5..-1]
 369             end
 370
 371             to_column_names = columns(to).map(&:name)
 372             columns = index.columns.map {|c| rename[c] || c }.select do |column|
 373               to_column_names.include?(column)
 374             end
 375
 376             unless columns.empty?
 377               # index name can't be the same
 378               opts = { :name => name.gsub(/_(#{from})_/, "_#{to}_") }
 379               opts[:unique] = true if index.unique
 380               add_index(to, columns, opts)
 381             end
 382           end
 383         end
 384
 385         def copy_table_contents(from, to, columns, rename = {}) #:nodoc:
 386           column_mappings = Hash[*columns.map {|name| [name, name]}.flatten]
 387           rename.inject(column_mappings) {|map, a| map[a.last] = a.first; map}
 388           from_columns = columns(from).collect {|col| col.name}
 389           columns = columns.find_all{|col| from_columns.include?(column_mappings[col])}
 390           quoted_columns = columns.map { |col| quote_column_name(col) } * ','
 391
 392           quoted_to = quote_table_name(to)
 393           @connection.execute "SELECT * FROM #{quote_table_name(from)}" do |row|
 394             sql = "INSERT INTO #{quoted_to} (#{quoted_columns}) VALUES ("
 395             sql << columns.map {|col| quote row[column_mappings[col]]} * ', '
 396             sql << ')'
 397             @connection.execute sql
 398           end
 399         end
 400
 401         def catch_schema_changes
 402           return yield
 403         rescue ActiveRecord::StatementInvalid => exception
 404           if exception.message =~ /database schema has changed/
 405             reconnect!
 406             retry
 407           else
 408             raise
 409           end
 410         end
 411
 412         def sqlite_version
 413           @sqlite_version ||= SQLiteAdapter::Version.new(select_value('select sqlite_version(*)'))
 414         end
 415
 416         def default_primary_key_type
 417           if supports_autoincrement?
 418             'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'.freeze
 419           else
 420             'INTEGER PRIMARY KEY NOT NULL'.freeze
 421           end
 422         end
 423     end
 424
 425     class SQLite2Adapter < SQLiteAdapter # :nodoc:
 426       def rename_table(name, new_name)
 427         move_table(name, new_name)
 428       end
 429     end
 430
 431     class DeprecatedSQLiteAdapter < SQLite2Adapter # :nodoc:
 432       def insert(sql, name = nil, pk = nil, id_value = nil)
 433         execute(sql, name = nil)
 434         id_value || @connection.last_insert_rowid
 435       end
 436     end
 437   end
 438 end