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module Foreigner
module ConnectionAdapters
module Sql2003
def supports_foreign_keys?
true
end
def drop_table(*args)
options = args.extract_options!
if options[:force]
disable_referential_integrity { super }
else
super
end
end
def foreign_key_exists?(from_table, options)
foreign_key_name = decipher_foreign_key_name(from_table, options)
foreign_keys(from_table).any? { |fk| fk.name == foreign_key_name }
end
def add_foreign_key(from_table, to_table, options = {})
sql = "ALTER TABLE #{quote_table_name(from_table)} #{add_foreign_key_sql(from_table, to_table, options)}"
execute(sql)
end
def add_foreign_key_sql(from_table, to_table, options = {})
column = options[:column] || "#{to_table.to_s.singularize}_id"
foreign_key_name = options.key?(:name) ? options[:name].to_s : foreign_key_name(from_table, column)
primary_key = options[:primary_key] || "id"
dependency = dependency_sql(options[:dependent])
proper_name = proper_table_name(to_table)
sql =
"ADD CONSTRAINT #{quote_column_name(foreign_key_name)} " +
"FOREIGN KEY (#{quote_column_name(column)}) " +
"REFERENCES #{quote_table_name(proper_name)}(#{primary_key})"
sql << " #{dependency}" if dependency.present?
sql << " #{options[:options]}" if options[:options]
sql
end
def proper_table_name(to_table)
if ActiveRecord::Migration.instance_methods(false).include? :proper_table_name
ActiveRecord::Migration.new.proper_table_name(to_table)
else
ActiveRecord::Migrator.proper_table_name(to_table)
end
end
def remove_foreign_key(table, options)
execute "ALTER TABLE #{quote_table_name(table)} #{remove_foreign_key_sql(table, options)}"
end
def remove_foreign_key_sql(table, options)
foreign_key_name = decipher_foreign_key_name(table, options)
"DROP CONSTRAINT #{quote_column_name(foreign_key_name)}"
end
private
def foreign_key_name(from_table, column)
"#{from_table}_#{column}_fk"
end
def foreign_key_column(to_table)
"#{to_table.to_s.singularize}_id"
end
def decipher_foreign_key_name(from_table, options)
if Hash === options
options.key?(:name) ? options[:name].to_s : foreign_key_name(from_table, options[:column])
else
foreign_key_name(from_table, foreign_key_column(options))
end
end
def dependency_sql(dependency)
case dependency
when :nullify then "ON DELETE SET NULL"
when :delete then "ON DELETE CASCADE"
when :restrict then "ON DELETE RESTRICT"
else ""
end
end
end
end
end
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