diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract')
4 files changed, 197 insertions, 14 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb index ff92375820..eb88845913 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb @@ -9,12 +9,7 @@ module ActiveRecord # records are quoted as their primary key return value.quoted_id if value.respond_to?(:quoted_id) - # FIXME: The only case we get an object other than nil or a real column - # is `SchemaStatements#add_column` with a PG array that has a non-empty default - # value. Is this really the only case? Are we missing tests for other types? - # We should have a real column object passed (or nil) here, and check for that - # instead - if column.respond_to?(:cast_type) + if column value = column.cast_type.type_cast_for_database(value) end @@ -29,12 +24,7 @@ module ActiveRecord return value.id end - # FIXME: The only case we get an object other than nil or a real column - # is `SchemaStatements#add_column` with a PG array that has a non-empty default - # value. Is this really the only case? Are we missing tests for other types? - # We should have a real column object passed (or nil) here, and check for that - # instead - if column.respond_to?(:cast_type) + if column value = column.cast_type.type_cast_for_database(value) end @@ -66,7 +56,7 @@ module ActiveRecord # This works for mysql and mysql2 where table.column can be used to # resolve ambiguity. # - # We override this in the sqlite and postgresql adapters to use only + # We override this in the sqlite3 and postgresql adapters to use only # the column name (as per syntax requirements). def quote_table_name_for_assignment(table, attr) quote_table_name("#{table}.#{attr}") diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb index 47fe501752..adad6cd542 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb @@ -23,6 +23,8 @@ module ActiveRecord def visit_AlterTable(o) sql = "ALTER TABLE #{quote_table_name(o.name)} " sql << o.adds.map { |col| visit_AddColumn col }.join(' ') + sql << o.foreign_key_adds.map { |fk| visit_AddForeignKey fk }.join(' ') + sql << o.foreign_key_drops.map { |fk| visit_DropForeignKey fk }.join(' ') end def visit_ColumnDefinition(o) @@ -41,6 +43,21 @@ module ActiveRecord create_sql end + def visit_AddForeignKey(o) + sql = <<-SQL.strip_heredoc + ADD CONSTRAINT #{quote_column_name(o.name)} + FOREIGN KEY (#{quote_column_name(o.column)}) + REFERENCES #{quote_table_name(o.to_table)} (#{quote_column_name(o.primary_key)}) + SQL + sql << " #{action_sql('DELETE', o.on_delete)}" if o.on_delete + sql << " #{action_sql('UPDATE', o.on_update)}" if o.on_update + sql + end + + def visit_DropForeignKey(name) + "DROP CONSTRAINT #{quote_column_name(name)}" + end + def column_options(o) column_options = {} column_options[:null] = o.null unless o.null.nil? @@ -77,6 +94,7 @@ module ActiveRecord def quote_value(value, column) column.sql_type ||= type_to_sql(column.type, column.limit, column.precision, column.scale) + column.cast_type ||= type_for_column(column) @conn.quote(value, column) end @@ -84,6 +102,23 @@ module ActiveRecord def options_include_default?(options) options.include?(:default) && !(options[:null] == false && options[:default].nil?) end + + def action_sql(action, dependency) + case dependency + when :nullify then "ON #{action} SET NULL" + when :cascade then "ON #{action} CASCADE" + when :restrict then "ON #{action} RESTRICT" + else + raise ArgumentError, <<-MSG.strip_heredoc + '#{dependency}' is not supported for :on_update or :on_delete. + Supported values are: :nullify, :cascade, :restrict + MSG + end + end + + def type_for_column(column) + @conn.lookup_cast_type(column.sql_type) + end end end end diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb index a9b3e9cfb9..98e6795f10 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb @@ -15,7 +15,7 @@ module ActiveRecord # are typically created by methods in TableDefinition, and added to the # +columns+ attribute of said TableDefinition object, in order to be used # for generating a number of table creation or table changing SQL statements. - class ColumnDefinition < Struct.new(:name, :type, :limit, :precision, :scale, :default, :null, :first, :after, :primary_key, :sql_type) #:nodoc: + class ColumnDefinition < Struct.new(:name, :type, :limit, :precision, :scale, :default, :null, :first, :after, :primary_key, :sql_type, :cast_type) #:nodoc: def primary_key? primary_key || type.to_sym == :primary_key @@ -25,6 +25,37 @@ module ActiveRecord class ChangeColumnDefinition < Struct.new(:column, :type, :options) #:nodoc: end + class ForeignKeyDefinition < Struct.new(:from_table, :to_table, :options) #:nodoc: + def name + options[:name] + end + + def column + options[:column] + end + + def primary_key + options[:primary_key] || default_primary_key + end + + def on_delete + options[:on_delete] + end + + def on_update + options[:on_update] + end + + def custom_primary_key? + options[:primary_key] != default_primary_key + end + + private + def default_primary_key + "id" + end + end + # Represents the schema of an SQL table in an abstract way. This class # provides methods for manipulating the schema representation. # @@ -303,14 +334,26 @@ module ActiveRecord class AlterTable # :nodoc: attr_reader :adds + attr_reader :foreign_key_adds + attr_reader :foreign_key_drops def initialize(td) @td = td @adds = [] + @foreign_key_adds = [] + @foreign_key_drops = [] end def name; @td.name; end + def add_foreign_key(to_table, options) + @foreign_key_adds << ForeignKeyDefinition.new(name, to_table, options) + end + + def drop_foreign_key(name) + @foreign_key_drops << name + end + def add_column(name, type, options) name = name.to_s type = type.to_sym diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb index 22823a8c58..5814c2b711 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -642,6 +642,115 @@ module ActiveRecord end alias :remove_belongs_to :remove_reference + # Returns an array of foreign keys for the given table. + # The foreign keys are represented as +ForeignKeyDefinition+ objects. + def foreign_keys(table_name) + raise NotImplementedError, "foreign_keys is not implemented" + end + + # Adds a new foreign key. +from_table+ is the table with the key column, + # +to_table+ contains the referenced primary key. + # + # The foreign key will be named after the following pattern: <tt>fk_rails_<identifier></tt>. + # +identifier+ is a 10 character long random string. A custom name can be specified with + # the <tt>:name</tt> option. + # + # ====== Creating a simple foreign key + # + # add_foreign_key :articles, :authors + # + # generates: + # + # ALTER TABLE "articles" ADD CONSTRAINT articles_author_id_fk FOREIGN KEY ("author_id") REFERENCES "authors" ("id") + # + # ====== Creating a foreign key on a specific column + # + # add_foreign_key :articles, :users, column: :author_id, primary_key: "lng_id" + # + # generates: + # + # ALTER TABLE "articles" ADD CONSTRAINT fk_rails_58ca3d3a82 FOREIGN KEY ("author_id") REFERENCES "users" ("lng_id") + # + # ====== Creating a cascading foreign key + # + # add_foreign_key :articles, :authors, on_delete: :cascade + # + # generates: + # + # ALTER TABLE "articles" ADD CONSTRAINT articles_author_id_fk FOREIGN KEY ("author_id") REFERENCES "authors" ("id") ON DELETE CASCADE + # + # The +options+ hash can include the following keys: + # [<tt>:column</tt>] + # The foreign key column name on +from_table+. Defaults to <tt>to_table.singularize + "_id"</tt> + # [<tt>:primary_key</tt>] + # The primary key column name on +to_table+. Defaults to +id+. + # [<tt>:name</tt>] + # The constraint name. Defaults to <tt>fk_rails_<identifier></tt>. + # [<tt>:on_delete</tt>] + # Action that happens <tt>ON DELETE</tt>. Valid values are +:nullify+, +:cascade:+ and +:restrict+ + # [<tt>:on_update</tt>] + # Action that happens <tt>ON UPDATE</tt>. Valid values are +:nullify+, +:cascade:+ and +:restrict+ + def add_foreign_key(from_table, to_table, options = {}) + return unless supports_foreign_keys? + + options[:column] ||= foreign_key_column_for(to_table) + + options = { + column: options[:column], + primary_key: options[:primary_key], + name: foreign_key_name(from_table, options), + on_delete: options[:on_delete], + on_update: options[:on_update] + } + at = create_alter_table from_table + at.add_foreign_key to_table, options + + execute schema_creation.accept(at) + end + + # Removes the given foreign key from the table. + # + # Removes the foreign key on +accounts.branch_id+. + # + # remove_foreign_key :accounts, :branches + # + # Removes the foreign key on +accounts.owner_id+. + # + # remove_foreign_key :accounts, column: :owner_id + # + # Removes the foreign key named +special_fk_name+ on the +accounts+ table. + # + # remove_foreign_key :accounts, name: :special_fk_name + # + def remove_foreign_key(from_table, options_or_to_table = {}) + return unless supports_foreign_keys? + + if options_or_to_table.is_a?(Hash) + options = options_or_to_table + else + options = { column: foreign_key_column_for(options_or_to_table) } + end + + fk_name_to_delete = options.fetch(:name) do + fk_to_delete = foreign_keys(from_table).detect {|fk| fk.column == options[:column] } + + if fk_to_delete + fk_to_delete.name + else + raise ArgumentError, "Table '#{from_table}' has no foreign key on column '#{options[:column]}'" + end + end + + at = create_alter_table from_table + at.drop_foreign_key fk_name_to_delete + + execute schema_creation.accept(at) + end + + def foreign_key_column_for(table_name) # :nodoc: + "#{table_name.to_s.singularize}_id" + end + def dump_schema_information #:nodoc: sm_table = ActiveRecord::Migrator.schema_migrations_table_name @@ -852,6 +961,12 @@ module ActiveRecord def create_alter_table(name) AlterTable.new create_table_definition(name, false, {}) end + + def foreign_key_name(table_name, options) # :nodoc: + options.fetch(:name) do + "fk_rails_#{SecureRandom.hex(5)}" + end + end end end end |