diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb new file mode 100644 index 0000000000..5c95b95184 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb @@ -0,0 +1,125 @@ +require 'active_support/core_ext/string/strip' + +module ActiveRecord + module ConnectionAdapters + class AbstractAdapter + class SchemaCreation # :nodoc: + def initialize(conn) + @conn = conn + @cache = {} + end + + def accept(o) + m = @cache[o.class] ||= "visit_#{o.class.name.split('::').last}" + send m, o + end + + def visit_AddColumn(o) + "ADD #{accept(o)}" + end + + private + + 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) + sql_type = type_to_sql(o.type, o.limit, o.precision, o.scale) + column_sql = "#{quote_column_name(o.name)} #{sql_type}" + add_column_options!(column_sql, column_options(o)) unless o.primary_key? + column_sql + end + + def visit_TableDefinition(o) + create_sql = "CREATE#{' TEMPORARY' if o.temporary} TABLE " + create_sql << "#{quote_table_name(o.name)} " + create_sql << "(#{o.columns.map { |c| accept c }.join(', ')}) " unless o.as + create_sql << "#{o.options}" + create_sql << " AS #{@conn.to_sql(o.as)}" if o.as + 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? + column_options[:default] = o.default unless o.default.nil? + column_options[:column] = o + column_options[:first] = o.first + column_options[:after] = o.after + column_options + end + + def quote_column_name(name) + @conn.quote_column_name name + end + + def quote_table_name(name) + @conn.quote_table_name name + end + + def type_to_sql(type, limit, precision, scale) + @conn.type_to_sql type.to_sym, limit, precision, scale + end + + def add_column_options!(sql, options) + sql << " DEFAULT #{quote_default_expression(options[:default], options[:column])}" if options_include_default?(options) + # must explicitly check for :null to allow change_column to work on migrations + if options[:null] == false + sql << " NOT NULL" + end + if options[:auto_increment] == true + sql << " AUTO_INCREMENT" + end + sql + end + + def quote_default_expression(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 + + 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 +end |