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author | Jeremy Kemper <jeremy@bitsweat.net> | 2005-11-16 08:18:13 +0000 |
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committer | Jeremy Kemper <jeremy@bitsweat.net> | 2005-11-16 08:18:13 +0000 |
commit | 9cb02c5317759ab4741fb2786173287879534c1c (patch) | |
tree | bc674616bfe0099bc7eb169b0a134a6aa32bc5b9 /activerecord/lib | |
parent | 2076dca63fde71693e4b8e23c4b1ace0a35b964f (diff) | |
download | rails-9cb02c5317759ab4741fb2786173287879534c1c.tar.gz rails-9cb02c5317759ab4741fb2786173287879534c1c.tar.bz2 rails-9cb02c5317759ab4741fb2786173287879534c1c.zip |
r3116@asus: jeremy | 2005-11-16 00:17:06 -0800
Introducing the Firebird adapter. Closes #1874.
git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3052 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
Diffstat (limited to 'activerecord/lib')
-rwxr-xr-x | activerecord/lib/active_record.rb | 2 | ||||
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/firebird_adapter.rb | 425 |
2 files changed, 426 insertions, 1 deletions
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb index 27ec3a6791..9aad0f028d 100755 --- a/activerecord/lib/active_record.rb +++ b/activerecord/lib/active_record.rb @@ -66,7 +66,7 @@ ActiveRecord::Base.class_eval do end unless defined?(RAILS_CONNECTION_ADAPTERS) - RAILS_CONNECTION_ADAPTERS = %w(mysql postgresql sqlite sqlserver db2 oci) + RAILS_CONNECTION_ADAPTERS = %w(mysql postgresql sqlite firebird sqlserver db2 oci) end RAILS_CONNECTION_ADAPTERS.each do |adapter| diff --git a/activerecord/lib/active_record/connection_adapters/firebird_adapter.rb b/activerecord/lib/active_record/connection_adapters/firebird_adapter.rb new file mode 100644 index 0000000000..6f151131b4 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/firebird_adapter.rb @@ -0,0 +1,425 @@ +# Author: Ken Kunz <kennethkunz@gmail.com> + +require 'active_record/connection_adapters/abstract_adapter' + +module FireRuby # :nodoc: all + class ResultSet + include Enumerable + end + + class Database + def self.new_from_params(database, host, port, service) + db_string = "" + if host + db_string << host + db_string << "/#{service || port}" if service || port + db_string << ":" + end + db_string << database + new(db_string) + end + end +end + +module ActiveRecord + class << Base + def firebird_connection(config) # :nodoc: + require_library_or_gem 'fireruby' + config = config.symbolize_keys + unless config.has_key?(:database) + raise ArgumentError, "No database specified. Missing argument: database." + end + options = config[:charset] ? { CHARACTER_SET => config[:charset] } : {} + db = FireRuby::Database.new_from_params(*config.values_at(:database, :host, :port, :service)) + connection = db.connect(config[:username], config[:password], options) + ConnectionAdapters::FirebirdAdapter.new(connection, logger) + end + end + + module ConnectionAdapters + class FirebirdColumn < Column # :nodoc: + VARCHAR_MAX_LENGTH = 32_765 + BLOB_MAX_LENGTH = 32_767 + + def initialize(name, domain_name, type, sub_type, length, precision, scale, default_source, null_flag) + column_type = metadata_to_column_type(type, sub_type) + sql_type = domain_name =~ /BOOLEAN/ ? 'BOOLEAN' : column_type + super(name.downcase, nil, sql_type, !null_flag) + if default_source + @default = parse_default(default_source) + @cast_type = firebird_cast_type(column_type, length, precision, scale) + end + @limit = type == 'BLOB' ? BLOB_MAX_LENGTH : length + end + + # Submits a _CAST_ query to the database, casting the default value to the specified SQL type. + # This enables Firebird to provide an actual value when context variables are used as column + # defaults (such as CURRENT_TIMESTAMP). + def default + if @default + sql = "SELECT CAST(#{@default} AS #{@cast_type}) FROM RDB$DATABASE" + connection = ActiveRecord::Base.active_connections.values.detect { |conn| conn && conn.adapter_name == 'Firebird' } + if connection + type_cast connection.execute(sql).to_a.first['CAST'] + else + raise ConnectionNotEstablished, "No Firebird connections established." + end + end + end + + def type_cast(value) + if type == :date and value.instance_of?(Time) + value.to_date + elsif type == :boolean + value == true or value == ActiveRecord::ConnectionAdapters::FirebirdAdapter.boolean_domain[:true] + else + super + end + end + + private + # Maps the internal type returned by Firebird metadata tables to a + # SQL type that can be passed to #firebird_cast_type and Column#new + def metadata_to_column_type(type, sub_type) + case type + when 'TEXT' then 'CHAR' + when 'VARYING' then 'VARCHAR' + when 'DOUBLE' then 'DOUBLE PRECISION' + when 'BLOB' then sub_type == 1 ? 'CLOB' : 'BLOB' + when 'SHORT', 'LONG', 'INT64' + case sub_type + when 1 then 'NUMERIC' + when 2 then 'DECIMAL' + else 'BIGINT' + end + else type + end + end + + def parse_default(default_source) + default_source =~ /^\s*DEFAULT\s+(.*)\s*$/i + return $1 unless $1.upcase == "NULL" + end + + # Returns a column definition that can be used in a Firebird CAST statement + def firebird_cast_type(column_type, length, precision, scale) + case column_type + when 'BLOB', 'CLOB' then "VARCHAR(#{VARCHAR_MAX_LENGTH})" + when 'CHAR', 'VARCHAR' then "#{column_type}(#{length})" + when 'NUMERIC', 'DECIMAL' then "#{column_type}(#{precision},#{scale.abs})" + else column_type + end + end + + def simplified_type(field_type) + if field_type == 'TIMESTAMP' + :datetime + else + super + end + end + end + + # The Firebird adapter relies on the FireRuby[http://rubyforge.org/projects/fireruby/] + # extension, version 0.3.2 or later (available as a gem or from + # RubyForge[http://rubyforge.org/projects/fireruby/]). FireRuby works with + # Firebird 1.5.x on Linux, OS X and Win32 platforms. + # + # == Usage Notes + # + # === Sequence (Generator) Names + # The Firebird adapter supports the same approach adopted for the Oracle + # adapter. See ActiveRecord::Base#set_sequence_name for more details. + # + # Note that in general there is no need to create a <tt>BEFORE INSERT</tt> + # trigger corresponding to a Firebird sequence generator when using + # ActiveRecord. In other words, you don't have to try to make Firebird + # simulate an <tt>AUTO_INCREMENT</tt> or +IDENTITY+ column. When saving a + # new record, ActiveRecord pre-fetches the next sequence value for the table + # and explicitly includes it in the +INSERT+ statement. (Pre-fetching the + # next primary key value is the only reliable method for the Firebird + # adapter to report back the +id+ after a successful insert.) + # + # === BOOLEAN Domain + # Firebird 1.5 does not provide a native +BOOLEAN+ type. But you can easily + # define a +BOOLEAN+ _domain_ for this purpose, e.g.: + # + # CREATE DOMAIN D_BOOLEAN AS SMALLINT CHECK (VALUE IN (0, 1)); + # + # When the Firebird adapter encounters a column that is based on a domain + # that includes "BOOLEAN" in the domain name, it will attempt to treat + # the column as a +BOOLEAN+. + # + # By default, the Firebird adapter will assume that the BOOLEAN domain is + # defined as above. This can be modified if needed. For example, if you + # have a legacy schema with the following +BOOLEAN+ domain defined: + # + # CREATE DOMAIN BOOLEAN AS CHAR(1) CHECK (VALUE IN ('T', 'F')); + # + # ...you can add the following line to your <tt>environment.rb</tt> file: + # + # ActiveRecord::ConnectionAdapters::FirebirdAdapter.boolean_domain = { :true => 'T', :false => 'F' } + # + # === BLOB Elements + # The Firebird adapter currently provides only limited support for +BLOB+ + # columns. You cannot currently retrieve or insert a +BLOB+ as an IO stream. + # When selecting a +BLOB+, the entire element is converted into a String. + # When inserting or updating a +BLOB+, the entire value is included in-line + # in the SQL statement, limiting you to values <= 32KB in size. + # + # === Column Name Case Semantics + # Firebird and ActiveRecord have somewhat conflicting case semantics for + # column names. + # + # [*Firebird*] + # The standard practice is to use unquoted column names, which can be + # thought of as case-insensitive. (In fact, Firebird converts them to + # uppercase.) Quoted column names (not typically used) are case-sensitive. + # [*ActiveRecord*] + # Attribute accessors corresponding to column names are case-sensitive. + # The defaults for primary key and inheritance columns are lowercase, and + # in general, people use lowercase attribute names. + # + # In order to map between the differing semantics in a way that conforms + # to common usage for both Firebird and ActiveRecord, uppercase column names + # in Firebird are converted to lowercase attribute names in ActiveRecord, + # and vice-versa. Mixed-case column names retain their case in both + # directions. Lowercase (quoted) Firebird column names are not supported. + # This is similar to the solutions adopted by other adapters. + # + # In general, the best approach is to use unqouted (case-insensitive) column + # names in your Firebird DDL (or if you must quote, use uppercase column + # names). These will correspond to lowercase attributes in ActiveRecord. + # + # For example, a Firebird table based on the following DDL: + # + # CREATE TABLE products ( + # id BIGINT NOT NULL PRIMARY KEY, + # "TYPE" VARCHAR(50), + # name VARCHAR(255) ); + # + # ...will correspond to an ActiveRecord model class called +Product+ with + # the following attributes: +id+, +type+, +name+. + # + # ==== Quoting <tt>"TYPE"</tt> and other Firebird reserved words: + # In ActiveRecord, the default inheritance column name is +type+. The word + # _type_ is a Firebird reserved word, so it must be quoted in any Firebird + # SQL statements. Because of the case mapping described above, you should + # always reference this column using quoted-uppercase syntax + # (<tt>"TYPE"</tt>) within Firebird DDL or other SQL statements (as in the + # example above). This holds true for any other Firebird reserved words used + # as column names as well. + # + # === Migrations + # The Firebird adapter does not currently support Migrations. I hope to + # add this feature in the near future. + # + # == Connection Options + # The following options are supported by the Firebird adapter. None of the + # options have default values. + # + # <tt>:database</tt>:: + # <i>Required option.</i> Specifies one of: (i) a Firebird database alias; + # (ii) the full path of a database file; _or_ (iii) a full Firebird + # connection string. <i>Do not specify <tt>:host</tt>, <tt>:service</tt> + # or <tt>:port</tt> as separate options when using a full connection + # string.</i> + # <tt>:host</tt>:: + # Set to <tt>"remote.host.name"</tt> for remote database connections. + # May be omitted for local connections if a full database path is + # specified for <tt>:database</tt>. Some platforms require a value of + # <tt>"localhost"</tt> for local connections when using a Firebird + # database _alias_. + # <tt>:service</tt>:: + # Specifies a service name for the connection. Only used if <tt>:host</tt> + # is provided. Required when connecting to a non-standard service. + # <tt>:port</tt>:: + # Specifies the connection port. Only used if <tt>:host</tt> is provided + # and <tt>:service</tt> is not. Required when connecting to a non-standard + # port and <tt>:service</tt> is not defined. + # <tt>:username</tt>:: + # Specifies the database user. May be omitted or set to +nil+ (together + # with <tt>:password</tt>) to use the underlying operating system user + # credentials on supported platforms. + # <tt>:password</tt>:: + # Specifies the database password. Must be provided if <tt>:username</tt> + # is explicitly specified; should be omitted if OS user credentials are + # are being used. + # <tt>:charset</tt>:: + # Specifies the character set to be used by the connection. Refer to + # Firebird documentation for valid options. + class FirebirdAdapter < AbstractAdapter + @@boolean_domain = { :true => 1, :false => 0 } + cattr_accessor :boolean_domain + + def adapter_name # :nodoc: + 'Firebird' + end + + # Returns true for Firebird adapter (since Firebird requires primary key + # values to be pre-fetched before insert). See also #next_sequence_value. + def prefetch_primary_key? + true + end + + def default_sequence_name(table_name, primary_key) # :nodoc: + "#{table_name}_seq" + end + + # QUOTING ================================================== + + def quote(value, column = nil) # :nodoc: + if [Time, DateTime].include?(value.class) + "CAST('#{value.strftime("%Y-%m-%d %H:%M:%S")}' AS TIMESTAMP)" + else + super + end + end + + def quote_string(string) # :nodoc: + string.gsub(/'/, "''") + end + + def quote_column_name(column_name) # :nodoc: + %Q("#{ar_to_fb_case(column_name)}") + end + + def quoted_true # :nodoc: + quote(boolean_domain[:true]) + end + + def quoted_false # :nodoc: + quote(boolean_domain[:false]) + end + + # DATABASE STATEMENTS ====================================== + + def select_all(sql, name = nil) # :nodoc: + select(sql, name) + end + + def select_one(sql, name = nil) # :nodoc: + result = select(sql, name) + result.nil? ? nil : result.first + end + + def execute(sql, name = nil, &block) # :nodoc: + log(sql, name) do + if @transaction + @connection.execute(sql, @transaction, &block) + else + @connection.execute_immediate(sql, &block) + end + end + end + + def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) # :nodoc: + execute(sql, name) + id_value + end + + alias_method :update, :execute + alias_method :delete, :execute + + def begin_db_transaction() # :nodoc: + @transaction = @connection.start_transaction + end + + def commit_db_transaction() # :nodoc: + @transaction.commit + ensure + @transaction = nil + end + + def rollback_db_transaction() # :nodoc: + @transaction.rollback + ensure + @transaction = nil + end + + def add_limit_offset!(sql, options) # :nodoc: + if options[:limit] + limit_string = "FIRST #{options[:limit]}" + limit_string << " SKIP #{options[:offset]}" if options[:offset] + sql.sub!(/\A(\s*SELECT\s)/i, '\&' + limit_string + ' ') + end + end + + # Returns the next sequence value from a sequence generator. Not generally + # called directly; used by ActiveRecord to get the next primary key value + # when inserting a new database record (see #prefetch_primary_key?). + def next_sequence_value(sequence_name) + FireRuby::Generator.new(sequence_name, @connection).next(1) + end + + # SCHEMA STATEMENTS ======================================== + + def columns(table_name, name = nil) # :nodoc: + sql = <<-END_SQL + SELECT r.rdb$field_name, r.rdb$field_source, t.rdb$type_name, f.rdb$field_sub_type, + f.rdb$field_length, f.rdb$field_precision, f.rdb$field_scale, + COALESCE(r.rdb$default_source, f.rdb$default_source) rdb$default_source, + COALESCE(r.rdb$null_flag, f.rdb$null_flag) rdb$null_flag + FROM rdb$relation_fields r + JOIN rdb$fields f ON r.rdb$field_source = f.rdb$field_name + JOIN rdb$types t ON f.rdb$field_type = t.rdb$type + WHERE r.rdb$relation_name = '#{table_name.upcase}' + AND t.rdb$field_name = 'RDB$FIELD_TYPE' + ORDER BY r.rdb$field_position + END_SQL + execute(sql, name).collect do |field| + field_values = field.values.collect do |value| + case value + when String then value.rstrip + when FireRuby::Blob then value.to_s + else value + end + end + FirebirdColumn.new(*field_values) + end + end + + private + def select(sql, name = nil) + execute(sql, name).collect do |row| + hashed_row = {} + # TODO: zip is slow. + row.aliases.zip(row.values) do |column_alias, value| + value = case value + when Time then guess_date_or_time(value) + when FireRuby::Blob then value.to_s + else value + end + hashed_row[fb_to_ar_case(column_alias)] = value + end + hashed_row + end + end + + # FireRuby (as of 0.3.2) returns a Time object for TIME, TIMESTAMP and + # DATE columns. This method guesses whether time is really a date, and + # returns a string representing the date if it is. This date string gets + # properly type-cast later (as a Time or Date object) based on the + # column type. + def guess_date_or_time(time) + if (time.hour + time.min + time.sec + time.usec).zero? + time.strftime("%Y-%m-%d") + else + time + end + end + + # Maps uppercase Firebird column names to lowercase for ActiveRecord; + # mixed-case columns retain their original case. + def fb_to_ar_case(column_name) + column_name =~ /[[:lower:]]/ ? column_name : column_name.downcase + end + + # Maps lowercase ActiveRecord column names to uppercase for Fierbird; + # mixed-case columns retain their original case. + def ar_to_fb_case(column_name) + column_name =~ /[[:upper:]]/ ? column_name : column_name.upcase + end + end + end +end |