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Rails Lighthouse ticket #4347

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foreign_keys-2.diff
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From ef0c4e8af82f7c49c6b10c5b4d3cfb5021d90133 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Wed, 7 Apr 2010 23:13:21 -0700
Subject: [PATCH 1/5] implementation without tests
 
---
.../abstract/schema_definitions.rb | 31 +++++++
.../abstract/schema_statements.rb | 88 ++++++++++++++++++++
.../connection_adapters/mysql_adapter.rb | 29 +++++++
.../connection_adapters/postgresql_adapter.rb | 48 +++++++++--
.../connection_adapters/sqlite_adapter.rb | 10 ++
activerecord/lib/active_record/schema_dumper.rb | 35 +++++++-
6 files changed, 233 insertions(+), 8 deletions(-)
 
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 6c477e4..4d29fdc 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -261,6 +261,9 @@ module ActiveRecord
class IndexDefinition < Struct.new(:table, :name, :unique, :columns) #:nodoc:
end
+ class ForeignKeyDefinition < Struct.new(:referencing_table, :referenced_table, :options) #:nodoc:
+ end
+
# Abstract representation of a column definition. Instances of this type
# are typically created by methods in TableDefinition, and added to the
# +columns+ attribute of said TableDefinition object, in order to be used
@@ -596,6 +599,21 @@ module ActiveRecord
@base.add_index(@table_name, column_name, options)
end
+ # Adds a new foreign key to the table. See SchemaStatements#add_foreign_key
+ #
+ # ===== Examples
+ # ====== Creating a simple foreign key
+ # t.foreign_key(:people)
+ # ====== Defining the column
+ # t.foreign_key(:people, :column => :sender_id)
+ # ====== Creating a named foreign key
+ # t.foreign_key(:people, :column => :sender_id, :name => 'sender_foreign_key')
+ # ====== Cascade delete this table if referenced_table is deleted.
+ # t.foreign_key(:people, :column => :sender_id, :dependency => :delete)
+ def foreign_key(referenced_table, options = {})
+ @base.add_foreign_key(@table_name, referenced_table, options)
+ end
+
# Adds timestamps (created_at and updated_at) columns to the table. See SchemaStatements#add_timestamps
# ===== Example
# t.timestamps
@@ -643,6 +661,19 @@ module ActiveRecord
@base.remove_index(@table_name, options)
end
+ # Remove the given foreign key from the table.
+ #
+ # ===== Examples
+ # ====== Remove the fk_suppliers_company_id in the suppliers table.
+ # t.remove_foreign_key :companies
+ # ====== Remove the foreign key named fk_accounts_branch_id in the accounts table.
+ # remove_foreign_key :column => :branch_id
+ # ====== Remove the foreign key named party_foreign_key in the accounts table.
+ # remove_index :name => :party_foreign_key
+ def remove_foreign_key(referenced_table_or_options)
+ @base.remove_foreign_key(@table_name, referenced_table_or_options)
+ end
+
# Removes the timestamp columns (created_at and updated_at) from the table.
# ===== Example
# t.remove_timestamps
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 6d4ab50..745e386 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -308,6 +308,94 @@ module ActiveRecord
end
end
+ # Adds a new foreign key to the +referencing_table+, pointing to the primary key of the +referenced_table+
+ #
+ # The foreign key will be named after the +referencing_table+ and column, unless you pass
+ # <tt>:name</tt> as an option.
+ #
+ # ===== Examples
+ # ====== Creating a foreign key
+ # add_foreign_key(:comments, :posts)
+ # generates
+ # ALTER TABLE `comments` ADD CONSTRAINT
+ # `fk_comments_post_id` FOREIGN KEY (`post_id`) REFERENCES `posts` (`id`)
+ #
+ # ====== Creating a named foreign key
+ # add_foreign_key(:comments, :posts, :name => 'comments_belongs_to_posts')
+ # generates
+ # ALTER TABLE `comments` ADD CONSTRAINT
+ # `comments_belongs_to_posts` FOREIGN KEY (`post_id`) REFERENCES `posts` (`id`)
+ #
+ # ====== Creating a cascading foreign_key on a custom column
+ # add_foreign_key(:people, :people, :column => 'best_friend_id', :dependent => :nullify)
+ # generates
+ # ALTER TABLE `people` ADD CONSTRAINT
+ # `fk_people_best_friend_id` FOREIGN KEY (`best_friend_id`) REFERENCES `people` (`id`)
+ # ON DELETE SET NULL
+ #
+ # === Supported options
+ # [:column]
+ # Specify the column name on the referencing_table that points to the referenced_table. By default
+ # this is guessed to be the singular name of the referenced_table with "_id" suffixed. So a referenced_table
+ # of :posts will use "post_id" as the default <tt>:column</tt>.
+ # [:name]
+ # Specify the name of the foreign key constraint. This defaults to use the referencing_table and column.
+ # [:primary_key]
+ # Specify the column name on the referenced_table that is referenced by this foreign key. This defaults to "id".
+ # [:dependent]
+ # If set to <tt>:delete</tt>, the associated records in the referencing_table are deleted when records
+ # in referenced_table are deleted. If set to <tt>:nullify</tt>, the foreign key column is set to +NULL+.
+ def add_foreign_key(referencing_table, referenced_table, options = {})
+ column = options[:column] || "#{referenced_table.to_s.singularize}_id"
+ foreign_key_name = foreign_key_name(referencing_table, options.merge(:column => column))
+ primary_key = options[:primary_key] || 'id'
+ dependency = foreign_key_dependency(options)
+
+ execute(
+ "ALTER TABLE #{quote_table_name(referencing_table)} " +
+ "ADD CONSTRAINT #{quote_column_name(foreign_key_name)} " +
+ "FOREIGN KEY (#{quote_column_name(column)}) " +
+ "REFERENCES #{quote_table_name(ActiveRecord::Migrator.proper_table_name(referenced_table))}(#{primary_key}) " +
+ dependency
+ )
+ end
+
+ # Remove the given foreign key from the table.
+ #
+ # Remove the foreign key fk_suppliers_company_id in the suppliers table.
+ # remove_foreign_key :suppliers, :companies
+ # Remove the foreign key fk_accounts_branch_id in the accounts table.
+ # remove_foreign_key :accounts, :column => :branch_id
+ # Remove the foreign key named party_foreign_key in the accounts table.
+ # remove_foreign_key :accounts, :name => :party_foreign_key
+ def remove_foreign_key(referencing_table, referenced_table_or_options)
+ if Hash === options
+ foreign_key_name = foreign_key_name(referencing_table, options)
+ else
+ foreign_key_name = foreign_key_name(referencing_table, :column => "#{referenced_table.to_s.singularize}_id")
+ end
+
+ execute "ALTER TABLE #{quote_table_name(referencing_table)} DROP FOREIGN KEY #{quote_column_name(foreign_key_name)}"
+ end
+
+ def foreign_key_name(referencing_table, options)
+ if options[:name]
+ options[:name]
+ elsif options[:column]
+ "fk_#{referencing_table}_#{options[:column]}"
+ else
+ raise ArgumentError, "You must specify the foreign key name"
+ end
+ end
+
+ def foreign_key_dependency(options)
+ case options[:dependency]
+ when :nullify then "ON DELETE SET NULL"
+ when :delete then "ON DELETE CASCADE"
+ else ""
+ end
+ end
+
# Returns a string of <tt>CREATE TABLE</tt> SQL statement(s) for recreating the
# entire structure of the database.
def structure_dump
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 55d9d20..1076a40 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -469,6 +469,35 @@ module ActiveRecord
result.free
indexes
end
+
+ def foreign_keys(table_name, name = nil)#:nodoc:
+ results = select_all(<<-SQL, name)
+ SELECT fk.referenced_table_name as 'referenced_table'
+ ,fk.referenced_column_name as 'primary_key'
+ ,fk.column_name as 'column'
+ ,fk.constraint_name as 'name'
+ FROM information_schema.key_column_usage fk
+ WHERE fk.referenced_column_name is not null
+ AND fk.table_schema = '#{@config[:database]}'
+ AND fk.table_name = '#{table_name}'
+ SQL
+
+ structure = select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
+
+ results.map do |row|
+ options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}
+
+ if structure =~ /CONSTRAINT #{quote_column_name(row['name'])} FOREIGN KEY .* REFERENCES .* ON DELETE (CASCADE|SET NULL)/
+ if $1 == 'CASCADE'
+ options[:dependent] = :delete
+ elsif $1 == 'SET NULL'
+ options[:dependent] = :nullify
+ end
+ end
+
+ ForeignKeyDefinition.new(table_name, row['referenced_table'], options)
+ end
+ end
def columns(table_name, name = nil)#:nodoc:
sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 2395a74..491c4c3 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -703,10 +703,7 @@ module ActiveRecord
ORDER BY i.relname
SQL
-
- indexes = []
-
- indexes = result.map do |row|
+ result.map do |row|
index_name = row[0]
unique = row[1] == 't'
indkey = row[2].split(" ")
@@ -721,10 +718,39 @@ module ActiveRecord
column_names = indkey.map {|attnum| columns[attnum] }
IndexDefinition.new(table_name, index_name, unique, column_names)
-
end
+ end
- indexes
+ def foreign_keys(table_name, name = nil)
+ results = select_all(<<-SQL, name)
+ SELECT tc.constraint_name as name
+ ,ccu.table_name as referenced_table
+ ,ccu.column_name as primary_key
+ ,kcu.column_name as column
+ ,rc.delete_rule as dependency
+ FROM information_schema.table_constraints tc
+ JOIN information_schema.key_column_usage kcu
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ JOIN information_schema.referential_constraints rc
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ JOIN information_schema.constraint_column_usage ccu
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ WHERE tc.constraint_type = 'FOREIGN KEY'
+ AND tc.constraint_catalog = '#{@config[:database]}'
+ AND tc.table_name = '#{table_name}'
+ SQL
+
+ results.map do |row|
+ options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}
+
+ if row['dependency'] == 'CASCADE'
+ options[:dependent] = :delete
+ elsif row['dependency'] == 'SET NULL'
+ options[:dependent] = :nullify
+ end
+
+ ForeignKeyDefinition.new(table_name, row['referenced_table'], options)
+ end
end
# Returns the list of all column definitions for a table.
@@ -922,6 +948,16 @@ module ActiveRecord
execute "DROP INDEX #{quote_table_name(index_name(table_name, options))}"
end
+ def remove_foreign_key(table, options)
+ if Hash === options
+ foreign_key_name = foreign_key_name(table, options[:column], options)
+ else
+ foreign_key_name = foreign_key_name(table, "#{options.to_s.singularize}_id")
+ end
+
+ execute "ALTER TABLE #{quote_table_name(table)} DROP CONSTRAINT #{quote_column_name(foreign_key_name)}"
+ end
+
# Maps logical Rails types to PostgreSQL-specific data types.
def type_to_sql(type, limit = nil, precision = nil, scale = nil)
return super unless type.to_s == 'integer'
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 29225b8..09ead91 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -211,6 +211,10 @@ module ActiveRecord
index
end
end
+
+ def foreign_keys(table_name, name = nil)
+ []
+ end
def primary_key(table_name) #:nodoc:
column = table_structure(table_name).find {|field| field['pk'].to_i == 1}
@@ -221,6 +225,12 @@ module ActiveRecord
execute "DROP INDEX #{quote_column_name(index_name(table_name, options))}"
end
+ def add_foreign_key(referencing_table, referenced_table, options = {})
+ end
+
+ def remove_foreign_key(referencing_table, referenced_table_or_options)
+ end
+
def rename_table(name, new_name)
execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
end
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index c8e1b4f..6bbe934 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -6,7 +6,7 @@ module ActiveRecord
# output format (i.e., ActiveRecord::Schema).
class SchemaDumper #:nodoc:
private_class_method :new
-
+
##
# :singleton-method:
# A list of tables which should not be dumped to the schema.
@@ -38,7 +38,7 @@ module ActiveRecord
def header(stream)
define_params = @version ? ":version => #{@version}" : ""
- stream.puts <<HEADER
+ stream.puts <<-HEADER
# This file is auto-generated from the current state of the database. Instead of editing this file,
# please use the migrations feature of Active Record to incrementally modify your database, and
# then regenerate this schema definition.
@@ -60,6 +60,8 @@ HEADER
end
def tables(stream)
+ fks = StringIO.new
+
@connection.tables.sort.each do |tbl|
next if ['schema_migrations', ignore_tables].flatten.any? do |ignored|
case ignored
@@ -70,7 +72,11 @@ HEADER
end
end
table(tbl, stream)
+ foreign_keys(tbl, fks)
end
+
+ fks.rewind
+ stream.print fks.read
end
def table(table, stream)
@@ -185,5 +191,30 @@ HEADER
stream.puts
end
end
+
+ def foreign_keys(table_name, stream)
+ if (foreign_keys = @connection.foreign_keys(table_name)).any?
+ add_foreign_key_statements = foreign_keys.map do |foreign_key|
+ statement_parts = [ ('add_foreign_key ' + foreign_key.referencing_table.inspect) ]
+ statement_parts << foreign_key.referenced_table.inspect
+ statement_parts << (':name => ' + foreign_key.options[:name].inspect)
+
+ if foreign_key.options[:column] != "#{foreign_key.referenced_table.singularize}_id"
+ statement_parts << (':column => ' + foreign_key.options[:column].inspect)
+ end
+ if foreign_key.options[:primary_key] != 'id'
+ statement_parts << (':primary_key => ' + foreign_key.options[:primary_key].inspect)
+ end
+ if foreign_key.options[:dependent].present?
+ statement_parts << (':dependent => ' + foreign_key.options[:dependent].inspect)
+ end
+
+ ' ' + statement_parts.join(', ')
+ end
+
+ stream.puts add_foreign_key_statements.sort.join("\n")
+ stream.puts
+ end
+ end
end
end
--
1.7.0.4
 
 
From 6e9ab8df9e7c5aae36bf66e7970e730385d6ca59 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 09:54:46 -0700
Subject: [PATCH 2/5] Tests, tweaks and docs
 
---
.../abstract/schema_statements.rb | 6 ++--
.../connection_adapters/abstract_adapter.rb | 6 +++++
.../connection_adapters/sqlite_adapter.rb | 4 +++
activerecord/lib/active_record/migration.rb | 3 ++
activerecord/test/cases/adapter_test.rb | 24 ++++++++++++++++++-
activerecord/test/cases/migration_test.rb | 18 +++++++++++++++
activerecord/test/cases/schema_dumper_test.rb | 4 +++
activerecord/test/schema/schema.rb | 24 +++++--------------
railties/guides/source/migrations.textile | 4 ++-
9 files changed, 70 insertions(+), 23 deletions(-)
 
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 745e386..b2ac01d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -368,11 +368,11 @@ module ActiveRecord
# remove_foreign_key :accounts, :column => :branch_id
# Remove the foreign key named party_foreign_key in the accounts table.
# remove_foreign_key :accounts, :name => :party_foreign_key
- def remove_foreign_key(referencing_table, referenced_table_or_options)
+ def remove_foreign_key(referencing_table, options)
if Hash === options
foreign_key_name = foreign_key_name(referencing_table, options)
else
- foreign_key_name = foreign_key_name(referencing_table, :column => "#{referenced_table.to_s.singularize}_id")
+ foreign_key_name = foreign_key_name(referencing_table, :column => "#{options.to_s.singularize}_id")
end
execute "ALTER TABLE #{quote_table_name(referencing_table)} DROP FOREIGN KEY #{quote_column_name(foreign_key_name)}"
@@ -389,7 +389,7 @@ module ActiveRecord
end
def foreign_key_dependency(options)
- case options[:dependency]
+ case options[:dependent]
when :nullify then "ON DELETE SET NULL"
when :delete then "ON DELETE CASCADE"
else ""
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 6ffffc8..9ea3801 100755
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -62,6 +62,12 @@ module ActiveRecord
false
end
+ # Does this adapter support foreign key constraints? This is +true+
+ # for all adapters except sqlite.
+ def supports_foreign_keys?
+ true
+ end
+
# Does this adapter support using DISTINCT within COUNT? This is +true+
# for all adapters except sqlite.
def supports_count_distinct?
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 09ead91..b002e86 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -84,6 +84,10 @@ module ActiveRecord
true
end
+ def supports_foreign_keys?
+ false
+ end
+
def requires_reloading?
true
end
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index c163fb9..d96de14 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -96,6 +96,9 @@ module ActiveRecord
# * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index with the name of the column. Other options include
# <tt>:name</tt> and <tt>:unique</tt> (e.g. <tt>{ :name => "users_name_index", :unique => true }</tt>).
# * <tt>remove_index(table_name, index_name)</tt>: Removes the index specified by +index_name+.
+ # * <tt>add_foreign_key(referencing_table, referenced_table, options)</tt>: Adds a new foreign key to the referencing_table,
+ # with a constraint on the primary key of the referenced_table. Options include <tt>:column</tt>, <tt>:name</tt>, <tt>:primary_key</tt>
+ # and <tt>:dependent</tt>. (e.g. <tt>{:name => 'my_foreign_key', :column => 'author_id', :dependent => :delete})
#
# == Irreversible transformations
#
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index 9f78ae0..f8ff892 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -41,6 +41,26 @@ class AdapterTest < ActiveRecord::TestCase
@connection.remove_index(:accounts, :name => idx_name) rescue nil
end
+ def test_foreign_keys
+ fk_name = 'favorited_author'
+
+ if @connection.supports_foreign_keys?
+ foreign_keys = @connection.foreign_keys("author_favorites")
+ assert foreign_keys.empty?
+
+ @connection.add_foreign_key :author_favorites, :authors, :name => fk_name, :column => 'favorite_author_id', :dependent => :delete
+ @connection.foreign_keys("author_favorites").first.tap do |foreign_key|
+ assert_equal 'author_favorites', foreign_key.referencing_table
+ assert_equal 'authors', foreign_key.referenced_table
+ assert_equal fk_name, foreign_key.options[:name]
+ assert_equal 'favorite_author_id', foreign_key.options[:column]
+ assert_equal :delete, foreign_key.options[:dependent]
+ end
+ end
+ ensure
+ @connection.remove_foreign_key :author_favorites, :name => fk_name
+ end
+
def test_current_database
if @connection.respond_to?(:current_database)
assert_equal ENV['ARUNIT_DB_NAME'] || "activerecord_unittest", @connection.current_database
@@ -136,7 +156,7 @@ class AdapterTest < ActiveRecord::TestCase
end
def test_foreign_key_violations_are_translated_to_specific_exception
- unless @connection.adapter_name == 'SQLite'
+ if @connection.supports_foreign_keys?
assert_raises(ActiveRecord::InvalidForeignKey) do
# Oracle adapter uses prefetched primary key values from sequence and passes them to connection adapter insert method
if @connection.prefetch_primary_key?
@@ -151,7 +171,7 @@ class AdapterTest < ActiveRecord::TestCase
def test_add_limit_offset_should_sanitize_sql_injection_for_limit_without_comas
sql_inject = "1 select * from schema"
- assert_equal " LIMIT 1", @connection.add_limit_offset!("", :limit => sql_inject)
+ assert_equal " LIMIT 1", @connection.add_limit_offset!("", :limit => sql_inject)
if current_adapter?(:MysqlAdapter)
assert_equal " LIMIT 7, 1", @connection.add_limit_offset!("", :limit => sql_inject, :offset => 7)
else
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index e213986..67a464e 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -111,6 +111,17 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_add_foreign_key
+ Subscription.delete_all
+ Order.delete_all
+ assert_nothing_raised { Subscription.connection.add_foreign_key :subscriptions, :books }
+ assert_nothing_raised { Subscription.connection.remove_foreign_key :subscriptions, :books }
+ assert_nothing_raised { Subscription.connection.add_foreign_key :subscriptions, :books, :name => 'fk_subscribed_books' }
+ assert_nothing_raised { Subscription.connection.remove_foreign_key :subscriptions, :name => 'fk_subscribed_books' }
+ assert_nothing_raised { Order.connection.add_foreign_key :orders, :people, :column => 'billing_customer_id'}
+ assert_nothing_raised { Order.connection.remove_foreign_key :orders, :column => 'billing_customer_id' }
+ end
+
def testing_table_with_only_foo_attribute
Person.connection.create_table :testings, :id => false do |t|
t.column :foo, :string
@@ -1606,6 +1617,13 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_foreign_key_creates_foreign_key
+ with_change_table do |t|
+ @connection.expects(:add_foreign_key).with(:delete_me, :bar, {:dependent => :delete})
+ t.foreign_key :bar, :dependent => :delete
+ end
+ end
+
def test_change_changes_column
with_change_table do |t|
@connection.expects(:change_column).with(:delete_me, :bar, :string, {})
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 1c43e3c..3af5698 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -162,6 +162,10 @@ class SchemaDumperTest < ActiveRecord::TestCase
assert_equal 'add_index "companies", ["firm_id", "type", "rating", "ruby_type"], :name => "company_index"', index_definition
end
+ def test_foreign_keys
+ output = standard_dump
+ end
+
def test_schema_dump_should_honor_nonstandard_primary_keys
output = standard_dump
match = output.match(%r{create_table "movies"(.*)do})
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index bec4291..18698cf 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -1,10 +1,4 @@
ActiveRecord::Schema.define do
- def except(adapter_names_to_exclude)
- unless [adapter_names_to_exclude].flatten.include?(adapter_name)
- yield
- end
- end
-
#put adapter specific setup here
case adapter_name
# For Firebird, set the sequence values 10000 when create_table is called;
@@ -545,18 +539,14 @@ ActiveRecord::Schema.define do
create_table :zines, :force => true do |t|
t.string :title
end
-
- except 'SQLite' do
- # fk_test_has_fk should be before fk_test_has_pk
- create_table :fk_test_has_fk, :force => true do |t|
- t.integer :fk_id, :null => false
- end
-
- create_table :fk_test_has_pk, :force => true do |t|
- end
-
- execute "ALTER TABLE fk_test_has_fk ADD CONSTRAINT fk_name FOREIGN KEY (#{quote_column_name 'fk_id'}) REFERENCES #{quote_table_name 'fk_test_has_pk'} (#{quote_column_name 'id'})"
+
+ create_table :fk_test_has_fk, :force => true do |t|
+ t.integer :fk_id, :null => false
+ end
+
+ create_table :fk_test_has_pk, :force => true do |t|
end
+ add_foreign_key :fk_test_has_fk, :fk_test_has_pk, :column => :fk_id, :name => 'fk_id'
end
Course.connection.create_table :courses, :force => true do |t|
diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile
index 558cbb4..c3fca91 100644
--- a/railties/guides/source/migrations.textile
+++ b/railties/guides/source/migrations.textile
@@ -75,6 +75,8 @@ Active Record provides methods that perform common data definition tasks in a da
* +remove_column+
* +add_index+
* +remove_index+
+* +add_foreign_key+
+* +remove_foreign_key+
If you need to perform tasks specific to your database (for example create a "foreign key":#active-record-and-referential-integrity constraint) then the +execute+ function allows you to execute arbitrary SQL. A migration is just a regular Ruby class so you're not limited to these functions. For example after adding a column you could write code to set the value of that column for existing records (if necessary using your models).
@@ -564,7 +566,7 @@ ActiveRecord::Schema.define(:version => 20080906171750) do
end
</ruby>
-In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and so on. Because this is database independent it could be loaded into any database that Active Record supports. This could be very useful if you were to distribute an application that is able to run against multiple databases.
+In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and +add_foreign_key+. Because this is database independent it could be loaded into any database that Active Record supports. This could be very useful if you were to distribute an application that is able to run against multiple databases.
There is however a trade-off: +db/schema.rb+ cannot express database specific items such as foreign key constraints, triggers or stored procedures. While in a migration you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database. If you are using features like this then you should set the schema format to +:sql+.
--
1.7.0.4
 
 
From e6cff6d8ce35e6bd9a85b17a24859621f31e6e7d Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 10:02:18 -0700
Subject: [PATCH 3/5] Add test for t.remove_foreign_key
 
---
activerecord/test/cases/migration_test.rb | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
 
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 67a464e..d64ecc8 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -1,7 +1,9 @@
require "cases/helper"
require 'bigdecimal/util'
+require 'models/order'
require 'models/person'
+require 'models/subscription'
require 'models/topic'
require 'models/developer'
@@ -1666,6 +1668,13 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_remove_foreign_key
+ with_change_table do |t|
+ @connection.expects(:remove_foreign_key).with(:delete_me, {:name => 'foo'})
+ t.remove_foreign_key :name => 'foo'
+ end
+ end
+
def test_rename_renames_column
with_change_table do |t|
@connection.expects(:rename_column).with(:delete_me, :bar, :baz)
--
1.7.0.4
 
 
From ea44ccd6872f19fea7489ba383ce446ade27dcce Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 10:29:30 -0700
Subject: [PATCH 4/5] Separate table dumps from foreign key dumps
 
---
activerecord/lib/active_record/schema_dumper.rb | 18 ++++++------------
1 files changed, 6 insertions(+), 12 deletions(-)
 
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 6bbe934..6e206c6 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -22,7 +22,8 @@ module ActiveRecord
def dump(stream)
header(stream)
- tables(stream)
+ table_names.each { |tbl| table(tbl, stream) }
+ table_names.each { |tbl| foreign_keys(tbl, stream) }
trailer(stream)
stream
end
@@ -59,24 +60,17 @@ HEADER
stream.puts "end"
end
- def tables(stream)
- fks = StringIO.new
-
- @connection.tables.sort.each do |tbl|
- next if ['schema_migrations', ignore_tables].flatten.any? do |ignored|
+ def table_names
+ @connection.tables.sort.reject do |tbl|
+ ['schema_migrations', ignore_tables].flatten.any? do |ignored|
case ignored
when String; tbl == ignored
when Regexp; tbl =~ ignored
else
raise StandardError, 'ActiveRecord::SchemaDumper.ignore_tables accepts an array of String and / or Regexp values.'
end
- end
- table(tbl, stream)
- foreign_keys(tbl, fks)
+ end
end
-
- fks.rewind
- stream.print fks.read
end
def table(table, stream)
--
1.7.0.4
 
 
From e96b4e5e5e3f240168f988f0afcfb6886a18d2eb Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 13:44:05 -0700
Subject: [PATCH 5/5] Complete foreign key tests in schema_dumper
 
---
activerecord/test/cases/schema_dumper_test.rb | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
 
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 3af5698..027d30b 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -162,8 +162,12 @@ class SchemaDumperTest < ActiveRecord::TestCase
assert_equal 'add_index "companies", ["firm_id", "type", "rating", "ruby_type"], :name => "company_index"', index_definition
end
- def test_foreign_keys
- output = standard_dump
+ def test_foreign_keys_dumped_after_tables
+ if ActiveRecord::Base.connection.supports_foreign_keys?
+ output = standard_dump
+ assert_match %r{create_table(.|\n)*add_foreign_key}, output
+ assert_no_match %r{add_foreign_key(.|\n)*create_table}, output
+ end
end
def test_schema_dump_should_honor_nonstandard_primary_keys
--
1.7.0.4
foreign_keys.diff
Diff
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742
From ab18f1b0f58ee9e154179c75462a438404ea4fe0 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Wed, 7 Apr 2010 23:13:21 -0700
Subject: [PATCH 1/4] implementation without tests
 
---
.../abstract/schema_definitions.rb | 31 +++++++
.../abstract/schema_statements.rb | 88 ++++++++++++++++++++
.../connection_adapters/mysql_adapter.rb | 29 +++++++
.../connection_adapters/postgresql_adapter.rb | 48 +++++++++--
.../connection_adapters/sqlite_adapter.rb | 10 ++
activerecord/lib/active_record/schema_dumper.rb | 35 +++++++-
6 files changed, 233 insertions(+), 8 deletions(-)
 
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 6c477e4..4d29fdc 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -261,6 +261,9 @@ module ActiveRecord
class IndexDefinition < Struct.new(:table, :name, :unique, :columns) #:nodoc:
end
+ class ForeignKeyDefinition < Struct.new(:referencing_table, :referenced_table, :options) #:nodoc:
+ end
+
# Abstract representation of a column definition. Instances of this type
# are typically created by methods in TableDefinition, and added to the
# +columns+ attribute of said TableDefinition object, in order to be used
@@ -596,6 +599,21 @@ module ActiveRecord
@base.add_index(@table_name, column_name, options)
end
+ # Adds a new foreign key to the table. See SchemaStatements#add_foreign_key
+ #
+ # ===== Examples
+ # ====== Creating a simple foreign key
+ # t.foreign_key(:people)
+ # ====== Defining the column
+ # t.foreign_key(:people, :column => :sender_id)
+ # ====== Creating a named foreign key
+ # t.foreign_key(:people, :column => :sender_id, :name => 'sender_foreign_key')
+ # ====== Cascade delete this table if referenced_table is deleted.
+ # t.foreign_key(:people, :column => :sender_id, :dependency => :delete)
+ def foreign_key(referenced_table, options = {})
+ @base.add_foreign_key(@table_name, referenced_table, options)
+ end
+
# Adds timestamps (created_at and updated_at) columns to the table. See SchemaStatements#add_timestamps
# ===== Example
# t.timestamps
@@ -643,6 +661,19 @@ module ActiveRecord
@base.remove_index(@table_name, options)
end
+ # Remove the given foreign key from the table.
+ #
+ # ===== Examples
+ # ====== Remove the fk_suppliers_company_id in the suppliers table.
+ # t.remove_foreign_key :companies
+ # ====== Remove the foreign key named fk_accounts_branch_id in the accounts table.
+ # remove_foreign_key :column => :branch_id
+ # ====== Remove the foreign key named party_foreign_key in the accounts table.
+ # remove_index :name => :party_foreign_key
+ def remove_foreign_key(referenced_table_or_options)
+ @base.remove_foreign_key(@table_name, referenced_table_or_options)
+ end
+
# Removes the timestamp columns (created_at and updated_at) from the table.
# ===== Example
# t.remove_timestamps
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 6d4ab50..745e386 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -308,6 +308,94 @@ module ActiveRecord
end
end
+ # Adds a new foreign key to the +referencing_table+, pointing to the primary key of the +referenced_table+
+ #
+ # The foreign key will be named after the +referencing_table+ and column, unless you pass
+ # <tt>:name</tt> as an option.
+ #
+ # ===== Examples
+ # ====== Creating a foreign key
+ # add_foreign_key(:comments, :posts)
+ # generates
+ # ALTER TABLE `comments` ADD CONSTRAINT
+ # `fk_comments_post_id` FOREIGN KEY (`post_id`) REFERENCES `posts` (`id`)
+ #
+ # ====== Creating a named foreign key
+ # add_foreign_key(:comments, :posts, :name => 'comments_belongs_to_posts')
+ # generates
+ # ALTER TABLE `comments` ADD CONSTRAINT
+ # `comments_belongs_to_posts` FOREIGN KEY (`post_id`) REFERENCES `posts` (`id`)
+ #
+ # ====== Creating a cascading foreign_key on a custom column
+ # add_foreign_key(:people, :people, :column => 'best_friend_id', :dependent => :nullify)
+ # generates
+ # ALTER TABLE `people` ADD CONSTRAINT
+ # `fk_people_best_friend_id` FOREIGN KEY (`best_friend_id`) REFERENCES `people` (`id`)
+ # ON DELETE SET NULL
+ #
+ # === Supported options
+ # [:column]
+ # Specify the column name on the referencing_table that points to the referenced_table. By default
+ # this is guessed to be the singular name of the referenced_table with "_id" suffixed. So a referenced_table
+ # of :posts will use "post_id" as the default <tt>:column</tt>.
+ # [:name]
+ # Specify the name of the foreign key constraint. This defaults to use the referencing_table and column.
+ # [:primary_key]
+ # Specify the column name on the referenced_table that is referenced by this foreign key. This defaults to "id".
+ # [:dependent]
+ # If set to <tt>:delete</tt>, the associated records in the referencing_table are deleted when records
+ # in referenced_table are deleted. If set to <tt>:nullify</tt>, the foreign key column is set to +NULL+.
+ def add_foreign_key(referencing_table, referenced_table, options = {})
+ column = options[:column] || "#{referenced_table.to_s.singularize}_id"
+ foreign_key_name = foreign_key_name(referencing_table, options.merge(:column => column))
+ primary_key = options[:primary_key] || 'id'
+ dependency = foreign_key_dependency(options)
+
+ execute(
+ "ALTER TABLE #{quote_table_name(referencing_table)} " +
+ "ADD CONSTRAINT #{quote_column_name(foreign_key_name)} " +
+ "FOREIGN KEY (#{quote_column_name(column)}) " +
+ "REFERENCES #{quote_table_name(ActiveRecord::Migrator.proper_table_name(referenced_table))}(#{primary_key}) " +
+ dependency
+ )
+ end
+
+ # Remove the given foreign key from the table.
+ #
+ # Remove the foreign key fk_suppliers_company_id in the suppliers table.
+ # remove_foreign_key :suppliers, :companies
+ # Remove the foreign key fk_accounts_branch_id in the accounts table.
+ # remove_foreign_key :accounts, :column => :branch_id
+ # Remove the foreign key named party_foreign_key in the accounts table.
+ # remove_foreign_key :accounts, :name => :party_foreign_key
+ def remove_foreign_key(referencing_table, referenced_table_or_options)
+ if Hash === options
+ foreign_key_name = foreign_key_name(referencing_table, options)
+ else
+ foreign_key_name = foreign_key_name(referencing_table, :column => "#{referenced_table.to_s.singularize}_id")
+ end
+
+ execute "ALTER TABLE #{quote_table_name(referencing_table)} DROP FOREIGN KEY #{quote_column_name(foreign_key_name)}"
+ end
+
+ def foreign_key_name(referencing_table, options)
+ if options[:name]
+ options[:name]
+ elsif options[:column]
+ "fk_#{referencing_table}_#{options[:column]}"
+ else
+ raise ArgumentError, "You must specify the foreign key name"
+ end
+ end
+
+ def foreign_key_dependency(options)
+ case options[:dependency]
+ when :nullify then "ON DELETE SET NULL"
+ when :delete then "ON DELETE CASCADE"
+ else ""
+ end
+ end
+
# Returns a string of <tt>CREATE TABLE</tt> SQL statement(s) for recreating the
# entire structure of the database.
def structure_dump
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 55d9d20..1076a40 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -469,6 +469,35 @@ module ActiveRecord
result.free
indexes
end
+
+ def foreign_keys(table_name, name = nil)#:nodoc:
+ results = select_all(<<-SQL, name)
+ SELECT fk.referenced_table_name as 'referenced_table'
+ ,fk.referenced_column_name as 'primary_key'
+ ,fk.column_name as 'column'
+ ,fk.constraint_name as 'name'
+ FROM information_schema.key_column_usage fk
+ WHERE fk.referenced_column_name is not null
+ AND fk.table_schema = '#{@config[:database]}'
+ AND fk.table_name = '#{table_name}'
+ SQL
+
+ structure = select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
+
+ results.map do |row|
+ options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}
+
+ if structure =~ /CONSTRAINT #{quote_column_name(row['name'])} FOREIGN KEY .* REFERENCES .* ON DELETE (CASCADE|SET NULL)/
+ if $1 == 'CASCADE'
+ options[:dependent] = :delete
+ elsif $1 == 'SET NULL'
+ options[:dependent] = :nullify
+ end
+ end
+
+ ForeignKeyDefinition.new(table_name, row['referenced_table'], options)
+ end
+ end
def columns(table_name, name = nil)#:nodoc:
sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 2395a74..491c4c3 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -703,10 +703,7 @@ module ActiveRecord
ORDER BY i.relname
SQL
-
- indexes = []
-
- indexes = result.map do |row|
+ result.map do |row|
index_name = row[0]
unique = row[1] == 't'
indkey = row[2].split(" ")
@@ -721,10 +718,39 @@ module ActiveRecord
column_names = indkey.map {|attnum| columns[attnum] }
IndexDefinition.new(table_name, index_name, unique, column_names)
-
end
+ end
- indexes
+ def foreign_keys(table_name, name = nil)
+ results = select_all(<<-SQL, name)
+ SELECT tc.constraint_name as name
+ ,ccu.table_name as referenced_table
+ ,ccu.column_name as primary_key
+ ,kcu.column_name as column
+ ,rc.delete_rule as dependency
+ FROM information_schema.table_constraints tc
+ JOIN information_schema.key_column_usage kcu
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ JOIN information_schema.referential_constraints rc
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ JOIN information_schema.constraint_column_usage ccu
+ USING (constraint_catalog, constraint_schema, constraint_name)
+ WHERE tc.constraint_type = 'FOREIGN KEY'
+ AND tc.constraint_catalog = '#{@config[:database]}'
+ AND tc.table_name = '#{table_name}'
+ SQL
+
+ results.map do |row|
+ options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}
+
+ if row['dependency'] == 'CASCADE'
+ options[:dependent] = :delete
+ elsif row['dependency'] == 'SET NULL'
+ options[:dependent] = :nullify
+ end
+
+ ForeignKeyDefinition.new(table_name, row['referenced_table'], options)
+ end
end
# Returns the list of all column definitions for a table.
@@ -922,6 +948,16 @@ module ActiveRecord
execute "DROP INDEX #{quote_table_name(index_name(table_name, options))}"
end
+ def remove_foreign_key(table, options)
+ if Hash === options
+ foreign_key_name = foreign_key_name(table, options[:column], options)
+ else
+ foreign_key_name = foreign_key_name(table, "#{options.to_s.singularize}_id")
+ end
+
+ execute "ALTER TABLE #{quote_table_name(table)} DROP CONSTRAINT #{quote_column_name(foreign_key_name)}"
+ end
+
# Maps logical Rails types to PostgreSQL-specific data types.
def type_to_sql(type, limit = nil, precision = nil, scale = nil)
return super unless type.to_s == 'integer'
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 29225b8..09ead91 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -211,6 +211,10 @@ module ActiveRecord
index
end
end
+
+ def foreign_keys(table_name, name = nil)
+ []
+ end
def primary_key(table_name) #:nodoc:
column = table_structure(table_name).find {|field| field['pk'].to_i == 1}
@@ -221,6 +225,12 @@ module ActiveRecord
execute "DROP INDEX #{quote_column_name(index_name(table_name, options))}"
end
+ def add_foreign_key(referencing_table, referenced_table, options = {})
+ end
+
+ def remove_foreign_key(referencing_table, referenced_table_or_options)
+ end
+
def rename_table(name, new_name)
execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
end
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index c8e1b4f..6bbe934 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -6,7 +6,7 @@ module ActiveRecord
# output format (i.e., ActiveRecord::Schema).
class SchemaDumper #:nodoc:
private_class_method :new
-
+
##
# :singleton-method:
# A list of tables which should not be dumped to the schema.
@@ -38,7 +38,7 @@ module ActiveRecord
def header(stream)
define_params = @version ? ":version => #{@version}" : ""
- stream.puts <<HEADER
+ stream.puts <<-HEADER
# This file is auto-generated from the current state of the database. Instead of editing this file,
# please use the migrations feature of Active Record to incrementally modify your database, and
# then regenerate this schema definition.
@@ -60,6 +60,8 @@ HEADER
end
def tables(stream)
+ fks = StringIO.new
+
@connection.tables.sort.each do |tbl|
next if ['schema_migrations', ignore_tables].flatten.any? do |ignored|
case ignored
@@ -70,7 +72,11 @@ HEADER
end
end
table(tbl, stream)
+ foreign_keys(tbl, fks)
end
+
+ fks.rewind
+ stream.print fks.read
end
def table(table, stream)
@@ -185,5 +191,30 @@ HEADER
stream.puts
end
end
+
+ def foreign_keys(table_name, stream)
+ if (foreign_keys = @connection.foreign_keys(table_name)).any?
+ add_foreign_key_statements = foreign_keys.map do |foreign_key|
+ statement_parts = [ ('add_foreign_key ' + foreign_key.referencing_table.inspect) ]
+ statement_parts << foreign_key.referenced_table.inspect
+ statement_parts << (':name => ' + foreign_key.options[:name].inspect)
+
+ if foreign_key.options[:column] != "#{foreign_key.referenced_table.singularize}_id"
+ statement_parts << (':column => ' + foreign_key.options[:column].inspect)
+ end
+ if foreign_key.options[:primary_key] != 'id'
+ statement_parts << (':primary_key => ' + foreign_key.options[:primary_key].inspect)
+ end
+ if foreign_key.options[:dependent].present?
+ statement_parts << (':dependent => ' + foreign_key.options[:dependent].inspect)
+ end
+
+ ' ' + statement_parts.join(', ')
+ end
+
+ stream.puts add_foreign_key_statements.sort.join("\n")
+ stream.puts
+ end
+ end
end
end
--
1.7.0.4
 
 
From e9e40c108fb403fb498b0d6e5c468a00c20604a9 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 09:54:46 -0700
Subject: [PATCH 2/4] Tests, tweaks and docs
 
---
.../abstract/schema_statements.rb | 6 ++--
.../connection_adapters/abstract_adapter.rb | 6 +++++
.../connection_adapters/sqlite_adapter.rb | 4 +++
activerecord/lib/active_record/migration.rb | 3 ++
activerecord/test/cases/adapter_test.rb | 24 ++++++++++++++++++-
activerecord/test/cases/migration_test.rb | 18 +++++++++++++++
activerecord/test/cases/schema_dumper_test.rb | 4 +++
activerecord/test/schema/schema.rb | 24 +++++--------------
railties/guides/source/migrations.textile | 4 ++-
9 files changed, 70 insertions(+), 23 deletions(-)
 
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 745e386..b2ac01d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -368,11 +368,11 @@ module ActiveRecord
# remove_foreign_key :accounts, :column => :branch_id
# Remove the foreign key named party_foreign_key in the accounts table.
# remove_foreign_key :accounts, :name => :party_foreign_key
- def remove_foreign_key(referencing_table, referenced_table_or_options)
+ def remove_foreign_key(referencing_table, options)
if Hash === options
foreign_key_name = foreign_key_name(referencing_table, options)
else
- foreign_key_name = foreign_key_name(referencing_table, :column => "#{referenced_table.to_s.singularize}_id")
+ foreign_key_name = foreign_key_name(referencing_table, :column => "#{options.to_s.singularize}_id")
end
execute "ALTER TABLE #{quote_table_name(referencing_table)} DROP FOREIGN KEY #{quote_column_name(foreign_key_name)}"
@@ -389,7 +389,7 @@ module ActiveRecord
end
def foreign_key_dependency(options)
- case options[:dependency]
+ case options[:dependent]
when :nullify then "ON DELETE SET NULL"
when :delete then "ON DELETE CASCADE"
else ""
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 6ffffc8..9ea3801 100755
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -62,6 +62,12 @@ module ActiveRecord
false
end
+ # Does this adapter support foreign key constraints? This is +true+
+ # for all adapters except sqlite.
+ def supports_foreign_keys?
+ true
+ end
+
# Does this adapter support using DISTINCT within COUNT? This is +true+
# for all adapters except sqlite.
def supports_count_distinct?
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 09ead91..b002e86 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -84,6 +84,10 @@ module ActiveRecord
true
end
+ def supports_foreign_keys?
+ false
+ end
+
def requires_reloading?
true
end
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index c163fb9..d96de14 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -96,6 +96,9 @@ module ActiveRecord
# * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index with the name of the column. Other options include
# <tt>:name</tt> and <tt>:unique</tt> (e.g. <tt>{ :name => "users_name_index", :unique => true }</tt>).
# * <tt>remove_index(table_name, index_name)</tt>: Removes the index specified by +index_name+.
+ # * <tt>add_foreign_key(referencing_table, referenced_table, options)</tt>: Adds a new foreign key to the referencing_table,
+ # with a constraint on the primary key of the referenced_table. Options include <tt>:column</tt>, <tt>:name</tt>, <tt>:primary_key</tt>
+ # and <tt>:dependent</tt>. (e.g. <tt>{:name => 'my_foreign_key', :column => 'author_id', :dependent => :delete})
#
# == Irreversible transformations
#
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index 9f78ae0..f8ff892 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -41,6 +41,26 @@ class AdapterTest < ActiveRecord::TestCase
@connection.remove_index(:accounts, :name => idx_name) rescue nil
end
+ def test_foreign_keys
+ fk_name = 'favorited_author'
+
+ if @connection.supports_foreign_keys?
+ foreign_keys = @connection.foreign_keys("author_favorites")
+ assert foreign_keys.empty?
+
+ @connection.add_foreign_key :author_favorites, :authors, :name => fk_name, :column => 'favorite_author_id', :dependent => :delete
+ @connection.foreign_keys("author_favorites").first.tap do |foreign_key|
+ assert_equal 'author_favorites', foreign_key.referencing_table
+ assert_equal 'authors', foreign_key.referenced_table
+ assert_equal fk_name, foreign_key.options[:name]
+ assert_equal 'favorite_author_id', foreign_key.options[:column]
+ assert_equal :delete, foreign_key.options[:dependent]
+ end
+ end
+ ensure
+ @connection.remove_foreign_key :author_favorites, :name => fk_name
+ end
+
def test_current_database
if @connection.respond_to?(:current_database)
assert_equal ENV['ARUNIT_DB_NAME'] || "activerecord_unittest", @connection.current_database
@@ -136,7 +156,7 @@ class AdapterTest < ActiveRecord::TestCase
end
def test_foreign_key_violations_are_translated_to_specific_exception
- unless @connection.adapter_name == 'SQLite'
+ if @connection.supports_foreign_keys?
assert_raises(ActiveRecord::InvalidForeignKey) do
# Oracle adapter uses prefetched primary key values from sequence and passes them to connection adapter insert method
if @connection.prefetch_primary_key?
@@ -151,7 +171,7 @@ class AdapterTest < ActiveRecord::TestCase
def test_add_limit_offset_should_sanitize_sql_injection_for_limit_without_comas
sql_inject = "1 select * from schema"
- assert_equal " LIMIT 1", @connection.add_limit_offset!("", :limit => sql_inject)
+ assert_equal " LIMIT 1", @connection.add_limit_offset!("", :limit => sql_inject)
if current_adapter?(:MysqlAdapter)
assert_equal " LIMIT 7, 1", @connection.add_limit_offset!("", :limit => sql_inject, :offset => 7)
else
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index e213986..67a464e 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -111,6 +111,17 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_add_foreign_key
+ Subscription.delete_all
+ Order.delete_all
+ assert_nothing_raised { Subscription.connection.add_foreign_key :subscriptions, :books }
+ assert_nothing_raised { Subscription.connection.remove_foreign_key :subscriptions, :books }
+ assert_nothing_raised { Subscription.connection.add_foreign_key :subscriptions, :books, :name => 'fk_subscribed_books' }
+ assert_nothing_raised { Subscription.connection.remove_foreign_key :subscriptions, :name => 'fk_subscribed_books' }
+ assert_nothing_raised { Order.connection.add_foreign_key :orders, :people, :column => 'billing_customer_id'}
+ assert_nothing_raised { Order.connection.remove_foreign_key :orders, :column => 'billing_customer_id' }
+ end
+
def testing_table_with_only_foo_attribute
Person.connection.create_table :testings, :id => false do |t|
t.column :foo, :string
@@ -1606,6 +1617,13 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_foreign_key_creates_foreign_key
+ with_change_table do |t|
+ @connection.expects(:add_foreign_key).with(:delete_me, :bar, {:dependent => :delete})
+ t.foreign_key :bar, :dependent => :delete
+ end
+ end
+
def test_change_changes_column
with_change_table do |t|
@connection.expects(:change_column).with(:delete_me, :bar, :string, {})
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 1c43e3c..3af5698 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -162,6 +162,10 @@ class SchemaDumperTest < ActiveRecord::TestCase
assert_equal 'add_index "companies", ["firm_id", "type", "rating", "ruby_type"], :name => "company_index"', index_definition
end
+ def test_foreign_keys
+ output = standard_dump
+ end
+
def test_schema_dump_should_honor_nonstandard_primary_keys
output = standard_dump
match = output.match(%r{create_table "movies"(.*)do})
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index bec4291..18698cf 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -1,10 +1,4 @@
ActiveRecord::Schema.define do
- def except(adapter_names_to_exclude)
- unless [adapter_names_to_exclude].flatten.include?(adapter_name)
- yield
- end
- end
-
#put adapter specific setup here
case adapter_name
# For Firebird, set the sequence values 10000 when create_table is called;
@@ -545,18 +539,14 @@ ActiveRecord::Schema.define do
create_table :zines, :force => true do |t|
t.string :title
end
-
- except 'SQLite' do
- # fk_test_has_fk should be before fk_test_has_pk
- create_table :fk_test_has_fk, :force => true do |t|
- t.integer :fk_id, :null => false
- end
-
- create_table :fk_test_has_pk, :force => true do |t|
- end
-
- execute "ALTER TABLE fk_test_has_fk ADD CONSTRAINT fk_name FOREIGN KEY (#{quote_column_name 'fk_id'}) REFERENCES #{quote_table_name 'fk_test_has_pk'} (#{quote_column_name 'id'})"
+
+ create_table :fk_test_has_fk, :force => true do |t|
+ t.integer :fk_id, :null => false
+ end
+
+ create_table :fk_test_has_pk, :force => true do |t|
end
+ add_foreign_key :fk_test_has_fk, :fk_test_has_pk, :column => :fk_id, :name => 'fk_id'
end
Course.connection.create_table :courses, :force => true do |t|
diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile
index 558cbb4..c3fca91 100644
--- a/railties/guides/source/migrations.textile
+++ b/railties/guides/source/migrations.textile
@@ -75,6 +75,8 @@ Active Record provides methods that perform common data definition tasks in a da
* +remove_column+
* +add_index+
* +remove_index+
+* +add_foreign_key+
+* +remove_foreign_key+
If you need to perform tasks specific to your database (for example create a "foreign key":#active-record-and-referential-integrity constraint) then the +execute+ function allows you to execute arbitrary SQL. A migration is just a regular Ruby class so you're not limited to these functions. For example after adding a column you could write code to set the value of that column for existing records (if necessary using your models).
@@ -564,7 +566,7 @@ ActiveRecord::Schema.define(:version => 20080906171750) do
end
</ruby>
-In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and so on. Because this is database independent it could be loaded into any database that Active Record supports. This could be very useful if you were to distribute an application that is able to run against multiple databases.
+In many ways this is exactly what it is. This file is created by inspecting the database and expressing its structure using +create_table+, +add_index+, and +add_foreign_key+. Because this is database independent it could be loaded into any database that Active Record supports. This could be very useful if you were to distribute an application that is able to run against multiple databases.
There is however a trade-off: +db/schema.rb+ cannot express database specific items such as foreign key constraints, triggers or stored procedures. While in a migration you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database. If you are using features like this then you should set the schema format to +:sql+.
--
1.7.0.4
 
 
From 818304962e4164e5ca7e89f1ad8277a0f04cf890 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 10:02:18 -0700
Subject: [PATCH 3/4] Add test for t.remove_foreign_key
 
---
activerecord/test/cases/migration_test.rb | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
 
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 67a464e..d64ecc8 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -1,7 +1,9 @@
require "cases/helper"
require 'bigdecimal/util'
+require 'models/order'
require 'models/person'
+require 'models/subscription'
require 'models/topic'
require 'models/developer'
@@ -1666,6 +1668,13 @@ if ActiveRecord::Base.connection.supports_migrations?
end
end
+ def test_remove_foreign_key
+ with_change_table do |t|
+ @connection.expects(:remove_foreign_key).with(:delete_me, {:name => 'foo'})
+ t.remove_foreign_key :name => 'foo'
+ end
+ end
+
def test_rename_renames_column
with_change_table do |t|
@connection.expects(:rename_column).with(:delete_me, :bar, :baz)
--
1.7.0.4
 
 
From 4304633099b638e043e4820f6bbbe645323dc746 Mon Sep 17 00:00:00 2001
From: Matthew <developer@matthewhiggins.com>
Date: Thu, 8 Apr 2010 10:29:30 -0700
Subject: [PATCH 4/4] Separate table dumps from foreign key dumps
 
---
activerecord/lib/active_record/schema_dumper.rb | 18 ++++++------------
1 files changed, 6 insertions(+), 12 deletions(-)
 
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 6bbe934..6e206c6 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -22,7 +22,8 @@ module ActiveRecord
def dump(stream)
header(stream)
- tables(stream)
+ table_names.each { |tbl| table(tbl, stream) }
+ table_names.each { |tbl| foreign_keys(tbl, stream) }
trailer(stream)
stream
end
@@ -59,24 +60,17 @@ HEADER
stream.puts "end"
end
- def tables(stream)
- fks = StringIO.new
-
- @connection.tables.sort.each do |tbl|
- next if ['schema_migrations', ignore_tables].flatten.any? do |ignored|
+ def table_names
+ @connection.tables.sort.reject do |tbl|
+ ['schema_migrations', ignore_tables].flatten.any? do |ignored|
case ignored
when String; tbl == ignored
when Regexp; tbl =~ ignored
else
raise StandardError, 'ActiveRecord::SchemaDumper.ignore_tables accepts an array of String and / or Regexp values.'
end
- end
- table(tbl, stream)
- foreign_keys(tbl, fks)
+ end
end
-
- fks.rewind
- stream.print fks.read
end
def table(table, stream)
--
1.7.0.4

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