Active Record SQLite3 轉接器

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 44
def dbconsole(config, options = {})
  args = []

  args << "-#{options[:mode]}" if options[:mode]
  args << "-header" if options[:header]
  args << File.expand_path(config.database, Rails.respond_to?(:root) ? Rails.root : nil)

  find_cmd_and_exec(ActiveRecord.database_cli[:sqlite], *args)
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 102
def initialize(...)
  super

  @memory_database = false
  case @config[:database].to_s
  when ""
    raise ArgumentError, "No database file specified. Missing argument: database"
  when ":memory:"
    @memory_database = true
  when /\Afile:/
  else
    # Otherwise we have a path relative to Rails.root
    @config[:database] = File.expand_path(@config[:database], Rails.root) if defined?(Rails.root)
    dirname = File.dirname(@config[:database])
    unless File.directory?(dirname)
      begin
        FileUtils.mkdir_p(dirname)
      rescue SystemCallError
        raise ActiveRecord::NoDatabaseError.new(connection_pool: @pool)
      end
    end
  end

  @last_affected_rows = nil
  @previous_read_uncommitted = nil
  @config[:strict] = ConnectionAdapters::SQLite3Adapter.strict_strings_by_default unless @config.key?(:strict)
  @connection_parameters = @config.merge(
    database: @config[:database].to_s,
    results_as_hash: true,
    default_transaction_mode: :immediate,
  )
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 34
def new_client(config)
  ::SQLite3::Database.new(config[:database].to_s, config)
rescue Errno::ENOENT => error
  if error.message.include?("No such file or directory")
    raise ActiveRecord::NoDatabaseError
  else
    raise
  end
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 67
class_attribute :strict_strings_by_default, default: false

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 392
def add_timestamps(table_name, **options)
  options[:null] = false if options[:null].nil?

  if !options.key?(:precision)
    options[:precision] = 6
  end

  alter_table(table_name) do |definition|
    definition.column :created_at, :datetime, **options
    definition.column :updated_at, :datetime, **options
  end
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 206
def connected?
  !(@raw_connection.nil? || @raw_connection.closed?)
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 308
def create_virtual_table(table_name, module_name, values)
  exec_query "CREATE VIRTUAL TABLE IF NOT EXISTS #{table_name} USING #{module_name} (#{values.join(", ")})"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 135
def database_exists?
  @config[:database] == ":memory:" || File.exist?(@config[:database].to_s)
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 216
def disconnect!
  super

  @raw_connection&.close rescue nil
  @raw_connection = nil
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 317
def drop_virtual_table(table_name, module_name, values, **options)
  drop_table(table_name)
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 232
def encoding
  any_raw_connection.encoding.to_s
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 412
def foreign_keys(table_name)
  # SQLite returns 1 row for each column of composite foreign keys.
  fk_info = internal_exec_query("PRAGMA foreign_key_list(#{quote(table_name)})", "SCHEMA")
  # Deferred or immediate foreign keys can only be seen in the CREATE TABLE sql
  fk_defs = table_structure_sql(table_name)
              .select do |column_string|
                column_string.start_with?("CONSTRAINT") &&
                column_string.include?("FOREIGN KEY")
              end
              .to_h do |fk_string|
                _, from, table, to = fk_string.match(FK_REGEX).to_a
                _, mode = fk_string.match(DEFERRABLE_REGEX).to_a
                deferred = mode&.downcase&.to_sym || false
                [[table, from, to], deferred]
              end

  grouped_fk = fk_info.group_by { |row| row["id"] }.values.each { |group| group.sort_by! { |row| row["seq"] } }
  grouped_fk.map do |group|
    row = group.first
    options = {
      on_delete: extract_foreign_key_action(row["on_delete"]),
      on_update: extract_foreign_key_action(row["on_update"]),
      deferrable: fk_defs[[row["table"], row["from"], row["to"]]]
    }

    if group.one?
      options[:column] = row["from"]
      options[:primary_key] = row["to"]
    else
      options[:column] = group.map { |row| row["from"] }
      options[:primary_key] = group.map { |row| row["to"] }
    end
    ForeignKeyDefinition.new(table_name, row["table"], options)
  end
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 325
def rename_table(table_name, new_name, **options)
  validate_table_length!(new_name) unless options[:_uses_legacy_table_name]
  schema_cache.clear_data_source_cache!(table_name.to_s)
  schema_cache.clear_data_source_cache!(new_name.to_s)
  exec_query "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
  rename_table_indexes(table_name, new_name, **options)
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 159
def requires_reloading?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 167
def supports_check_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 183
def supports_common_table_expressions?
  database_version >= "3.8.3"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 198
def supports_concurrent_connections?
  !@memory_database
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 175
def supports_datetime_with_precision?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 139
def supports_ddl_transactions?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 244
def supports_deferrable_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 236
def supports_explain?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 155
def supports_expression_index?
  database_version >= "3.9.0"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 163
def supports_foreign_keys?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 223
def supports_index_sort_order?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 191
def supports_insert_on_conflict?
  database_version >= "3.24.0"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 187
def supports_insert_returning?
  database_version >= "3.35.0"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 179
def supports_json?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 240
def supports_lazy_transactions?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 151
def supports_partial_index?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 143
def supports_savepoints?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 147
def supports_transaction_isolation?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 171
def supports_views?
  true
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 202
def supports_virtual_columns?
  database_version >= "3.31.0"
end

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 292
      def virtual_tables
        query = <<~SQL
          SELECT name, sql FROM sqlite_master WHERE sql LIKE 'CREATE VIRTUAL %';
        SQL

        exec_query(query, "SCHEMA").cast_values.each_with_object({}) do |row, memo|
          table_name, sql = row[0], row[1]
          _, module_name, arguments = sql.match(VIRTUAL_TABLE_REGEX).to_a
          memo[table_name] = [module_name, arguments]
        end.to_a
      end