diff options
15 files changed, 286 insertions, 37 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index e6cbd6bd68..2562e26a11 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,3 +1,20 @@ +* Add support for database schema comments for tables, columns and indexes + for PostgreSQL and MySQL. + + It allows to specify commentaries for database objects in migrations and + store them in database itself, allowing to see them with DBA tools and + in `db/schema.rb` file and thus automatically documents database schema: + + create_table "pages", force: :cascade, comment: 'Arbitrary content pages' do |t| + # ... + t.string "path", comment: "Path fragment of page URL used for routing" + t.string "locale", comment: "RFC 3066 locale code of website language section" + t.index ["locale", "path"], name: 'page_uri_index' comment: "Main index used to lookup page by it's URI." + # ... + end + + *Andrey Novikov* + * Add `quoted_time` for truncating the date part of a TIME column value. This fixes queries on TIME column on MariaDB, as it doesn't ignore the date part of the string when it coerces to time. 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 0ba4d94e3c..f3f1618473 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb @@ -54,6 +54,7 @@ module ActiveRecord end create_sql << "(#{statements.join(', ')}) " if statements.present? + add_table_options!(create_sql, table_options(o)) create_sql << "#{o.options}" create_sql << " AS #{@conn.to_sql(o.as)}" if o.as create_sql @@ -82,6 +83,16 @@ module ActiveRecord "DROP CONSTRAINT #{quote_column_name(name)}" end + def table_options(o) + options = {} + options[:comment] = o.comment + options + end + + def add_table_options!(sql, _options) + sql + end + def column_options(o) column_options = {} column_options[:null] = o.null unless o.null.nil? @@ -92,6 +103,7 @@ module ActiveRecord column_options[:auto_increment] = o.auto_increment column_options[:primary_key] = o.primary_key column_options[:collation] = o.collation + column_options[:comment] = o.comment column_options 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 4f97c7c065..1603c38e35 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb @@ -3,14 +3,14 @@ module ActiveRecord # Abstract representation of an index definition on a table. Instances of # this type are typically created and returned by methods in database # adapters. e.g. ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter#indexes - class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where, :type, :using) #:nodoc: + class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where, :type, :using, :comment) #: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 # 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, :auto_increment, :primary_key, :collation, :sql_type) #:nodoc: + class ColumnDefinition < Struct.new(:name, :type, :limit, :precision, :scale, :default, :null, :first, :after, :auto_increment, :primary_key, :collation, :sql_type, :comment) #:nodoc: def primary_key? primary_key || type.to_sym == :primary_key @@ -207,9 +207,9 @@ module ActiveRecord include ColumnMethods attr_accessor :indexes - attr_reader :name, :temporary, :options, :as, :foreign_keys + attr_reader :name, :temporary, :options, :as, :foreign_keys, :comment - def initialize(name, temporary, options, as = nil) + def initialize(name, temporary, options, as = nil, comment = nil) @columns_hash = {} @indexes = {} @foreign_keys = [] @@ -218,6 +218,7 @@ module ActiveRecord @options = options @as = as @name = name + @comment = comment end def primary_keys(name = nil) # :nodoc: @@ -373,6 +374,7 @@ module ActiveRecord column.auto_increment = options[:auto_increment] column.primary_key = type == :primary_key || options[:primary_key] column.collation = options[:collation] + column.comment = options[:comment] column end diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb index 4880d216d6..69d2780f7c 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb @@ -46,12 +46,14 @@ module ActiveRecord spec[:collation] = collation end + spec[:comment] = column.comment.inspect if column.comment + spec end # Lists the valid migration options def migration_keys - [:name, :limit, :precision, :scale, :default, :null, :collation] + [:name, :limit, :precision, :scale, :default, :null, :collation, :comment] end private 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 020d9bbdca..3bbd5a9515 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -18,6 +18,11 @@ module ActiveRecord nil end + # Returns comment associated with given table in database + def table_comment(table_name) + nil + end + # Truncates a table alias according to the limits of the current adapter. def table_alias_for(table_name) table_name[0...table_alias_length].tr('.', '_') @@ -255,7 +260,7 @@ module ActiveRecord # # See also TableDefinition#column for details on how to create columns. def create_table(table_name, options = {}) - td = create_table_definition table_name, options[:temporary], options[:options], options[:as] + td = create_table_definition table_name, options[:temporary], options[:options], options[:as], options[:comment] if options[:id] != false && !options[:as] pk = options.fetch(:primary_key) do @@ -265,7 +270,7 @@ module ActiveRecord if pk.is_a?(Array) td.primary_keys pk else - td.primary_key pk, options.fetch(:id, :primary_key), options + td.primary_key pk, options.fetch(:id, :primary_key), options.except(:comment) end end @@ -283,6 +288,13 @@ module ActiveRecord end end + if supports_comments? && !supports_comments_in_create? + change_table_comment(table_name, options[:comment]) if options[:comment] + td.columns.each do |column| + change_column_comment(table_name, column.name, column.comment) if column.comment + end + end + result end @@ -1078,7 +1090,7 @@ module ActiveRecord def add_index_options(table_name, column_name, options = {}) #:nodoc: column_names = Array(column_name) - options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm, :type) + options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm, :type, :comment) index_type = options[:type].to_s if options.key?(:type) index_type ||= options[:unique] ? "UNIQUE" : "" @@ -1106,13 +1118,25 @@ module ActiveRecord end index_columns = quoted_columns_for_index(column_names, options).join(", ") - [index_name, index_type, index_columns, index_options, algorithm, using] + comment = options[:comment] if options.key?(:comment) + + [index_name, index_type, index_columns, index_options, algorithm, using, comment] end def options_include_default?(options) options.include?(:default) && !(options[:null] == false && options[:default].nil?) end + # Adds comment for given table or drops it if +nil+ given + def change_table_comment(table_name, comment) + raise NotImplementedError, "change_table_comment is not implemented" + end + + # Adds comment for given table column or drops it if +nil+ given + def change_column_comment(table_name, column_name, comment) #:nodoc: + raise NotImplementedError, "change_column_comment is not implemented" + end + protected def add_index_sort_order(option_strings, column_names, options = {}) if options.is_a?(Hash) && order = options[:order] @@ -1194,8 +1218,8 @@ module ActiveRecord end private - def create_table_definition(name, temporary = false, options = nil, as = nil) - TableDefinition.new(name, temporary, options, as) + def create_table_definition(name, temporary = false, options = nil, as = nil, comment = nil) + TableDefinition.new(name, temporary, options, as, comment) end def create_alter_table(name) diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb index 069346253a..b753c348de 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb @@ -278,6 +278,16 @@ module ActiveRecord false end + # Does adapter supports comments on database objects (tables, columns, indexes)? + def supports_comments? + false + end + + # Can comments for tables, columns, and indexes be specified in create/alter table statements? + def supports_comments_in_create? + false + end + # This is meant to be implemented by the adapters that support extensions def disable_extension(name) end diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb index 8bd9da4fbc..cea5a04006 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb @@ -160,8 +160,8 @@ module ActiveRecord raise NotImplementedError end - def new_column(field, default, sql_type_metadata, null, table_name, default_function = nil, collation = nil) # :nodoc: - MySQL::Column.new(field, default, sql_type_metadata, null, table_name, default_function, collation) + def new_column(field, default, sql_type_metadata, null, table_name, default_function = nil, collation = nil, comment = nil) # :nodoc: + MySQL::Column.new(field, default, sql_type_metadata, null, table_name, default_function, collation, comment) end # Must return the MySQL error number from the exception, if the exception has an @@ -373,7 +373,7 @@ module ActiveRecord mysql_index_type = row[:Index_type].downcase.to_sym index_type = INDEX_TYPES.include?(mysql_index_type) ? mysql_index_type : nil index_using = INDEX_USINGS.include?(mysql_index_type) ? mysql_index_type : nil - indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], [], nil, nil, index_type, index_using) + indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], [], nil, nil, index_type, index_using, row[:Index_comment].presence) end indexes.last.columns << row[:Column_name] @@ -394,10 +394,18 @@ module ActiveRecord else default, default_function = field[:Default], nil end - new_column(field[:Field], default, type_metadata, field[:Null] == "YES", table_name, default_function, field[:Collation]) + new_column(field[:Field], default, type_metadata, field[:Null] == "YES", table_name, default_function, field[:Collation], field[:Comment].presence) end end + def table_comment(table_name) + select_value(<<-SQL.strip_heredoc, 'SCHEMA') + SELECT table_comment + FROM INFORMATION_SCHEMA.TABLES + WHERE table_name=#{quote(table_name)}; + SQL + end + def create_table(table_name, options = {}) #:nodoc: super(table_name, options.reverse_merge(:options => "ENGINE=InnoDB")) end @@ -482,8 +490,10 @@ module ActiveRecord end def add_index(table_name, column_name, options = {}) #:nodoc: - index_name, index_type, index_columns, _, index_algorithm, index_using = add_index_options(table_name, column_name, options) - execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} ON #{quote_table_name(table_name)} (#{index_columns}) #{index_algorithm}" + index_name, index_type, index_columns, _, index_algorithm, index_using, comment = add_index_options(table_name, column_name, options) + sql = "CREATE #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} ON #{quote_table_name(table_name)} (#{index_columns}) #{index_algorithm}" + sql << " COMMENT #{quote(comment)}" if comment + execute sql end def foreign_keys(table_name) @@ -521,7 +531,12 @@ module ActiveRecord raw_table_options = create_table_info.sub(/\A.*\n\) /m, '').sub(/\n\/\*!.*\*\/\n\z/m, '').strip # strip AUTO_INCREMENT - raw_table_options.sub(/(ENGINE=\w+)(?: AUTO_INCREMENT=\d+)/, '\1') + raw_table_options.sub!(/(ENGINE=\w+)(?: AUTO_INCREMENT=\d+)/, '\1') + + # strip COMMENT + raw_table_options.sub!(/ COMMENT='.+'/, '') + + raw_table_options end # Maps logical Rails types to MySQL-specific data types. @@ -866,8 +881,8 @@ module ActiveRecord create_table_info_cache[table_name] ||= select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"] end - def create_table_definition(name, temporary = false, options = nil, as = nil) # :nodoc: - MySQL::TableDefinition.new(name, temporary, options, as) + def create_table_definition(name, temporary = false, options = nil, as = nil, comment = nil) # :nodoc: + MySQL::TableDefinition.new(name, temporary, options, as, comment) end def integer_to_sql(limit) # :nodoc: diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb index 2e718b29fa..1c798d99f2 100644 --- a/activerecord/lib/active_record/connection_adapters/column.rb +++ b/activerecord/lib/active_record/connection_adapters/column.rb @@ -5,7 +5,7 @@ module ActiveRecord module ConnectionAdapters # An abstract definition of a column in a table. class Column - attr_reader :name, :default, :sql_type_metadata, :null, :table_name, :default_function, :collation + attr_reader :name, :default, :sql_type_metadata, :null, :table_name, :default_function, :collation, :comment delegate :precision, :scale, :limit, :type, :sql_type, to: :sql_type_metadata, allow_nil: true @@ -15,7 +15,7 @@ module ActiveRecord # +default+ is the type-casted default value, such as +new+ in <tt>sales_stage varchar(20) default 'new'</tt>. # +sql_type_metadata+ is various information about the type of the column # +null+ determines if this column allows +NULL+ values. - def initialize(name, default, sql_type_metadata = nil, null = true, table_name = nil, default_function = nil, collation = nil) + def initialize(name, default, sql_type_metadata = nil, null = true, table_name = nil, default_function = nil, collation = nil, comment = nil) @name = name.freeze @table_name = table_name @sql_type_metadata = sql_type_metadata @@ -23,6 +23,7 @@ module ActiveRecord @default = default @default_function = default_function @collation = collation + @comment = comment end def has_default? diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb index 1e2c859af9..5ab81640e8 100644 --- a/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb +++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_creation.rb @@ -2,6 +2,9 @@ module ActiveRecord module ConnectionAdapters module MySQL class SchemaCreation < AbstractAdapter::SchemaCreation + delegate :quote, to: :@conn + private :quote + private def visit_DropForeignKey(name) @@ -22,6 +25,13 @@ module ActiveRecord add_column_position!(change_column_sql, column_options(o.column)) end + def add_table_options!(sql, options) + super + if options[:comment] + sql << "COMMENT #{quote(options[:comment])} " + end + end + def column_options(o) column_options = super column_options[:charset] = o.charset @@ -35,7 +45,11 @@ module ActiveRecord if options[:collation] sql << " COLLATE #{options[:collation]}" end - super + new_sql = super + if options[:comment] + new_sql << " COMMENT #{quote(options[:comment])}" + end + new_sql end def add_column_position!(sql, options) @@ -48,8 +62,9 @@ module ActiveRecord end def index_in_create(table_name, column_name, options) - index_name, index_type, index_columns, _, _, index_using = @conn.add_index_options(table_name, column_name, options) - "#{index_type} INDEX #{quote_column_name(index_name)} #{index_using} (#{index_columns}) " + index_name, index_type, index_columns, _, _, index_using, comment = @conn.add_index_options(table_name, column_name, options) + index_option = " COMMENT #{quote(comment)}" if comment + "#{index_type} INDEX #{quote_column_name(index_name)} #{index_using} (#{index_columns})#{index_option} " end end end diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb index e7541748de..ec343a5a57 100644 --- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb @@ -45,6 +45,14 @@ module ActiveRecord !mariadb? && version >= '5.7.8' end + def supports_comments? + true + end + + def supports_comments_in_create? + true + end + # HELPER METHODS =========================================== def each_hash(result) # :nodoc: diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb index 39e8492688..36331204f7 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb @@ -1,3 +1,5 @@ +require 'active_support/core_ext/string/strip' + module ActiveRecord module ConnectionAdapters module PostgreSQL @@ -172,7 +174,8 @@ module ActiveRecord table = Utils.extract_schema_qualified_name(table_name.to_s) result = query(<<-SQL, 'SCHEMA') - SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid + SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid, + pg_catalog.obj_description(i.oid, 'pg_class') AS comment FROM pg_class t INNER JOIN pg_index d ON t.oid = d.indrelid INNER JOIN pg_class i ON d.indexrelid = i.oid @@ -190,6 +193,7 @@ module ActiveRecord indkey = row[2].split(" ").map(&:to_i) inddef = row[3] oid = row[4] + comment = row[5] columns = Hash[query(<<-SQL, "SCHEMA")] SELECT a.attnum, a.attname @@ -207,7 +211,7 @@ module ActiveRecord where = inddef.scan(/WHERE (.+)$/).flatten[0] using = inddef.scan(/USING (.+?) /).flatten[0].to_sym - IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using) + IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using, comment) end end.compact end @@ -215,18 +219,33 @@ module ActiveRecord # Returns the list of all column definitions for a table. def columns(table_name) # :nodoc: table_name = table_name.to_s - column_definitions(table_name).map do |column_name, type, default, notnull, oid, fmod, collation| + column_definitions(table_name).map do |column_name, type, default, notnull, oid, fmod, collation, comment| oid = oid.to_i fmod = fmod.to_i type_metadata = fetch_type_metadata(column_name, type, oid, fmod) default_value = extract_value_from_default(default) default_function = extract_default_function(default_value, default) - new_column(column_name, default_value, type_metadata, !notnull, table_name, default_function, collation) + new_column(column_name, default_value, type_metadata, !notnull, table_name, default_function, collation, comment) end end - def new_column(name, default, sql_type_metadata, null, table_name, default_function = nil, collation = nil) # :nodoc: - PostgreSQLColumn.new(name, default, sql_type_metadata, null, table_name, default_function, collation) + def new_column(name, default, sql_type_metadata, null, table_name, default_function = nil, collation = nil, comment = nil) # :nodoc: + PostgreSQLColumn.new(name, default, sql_type_metadata, null, table_name, default_function, collation, comment) + end + + # Returns a comment stored in database for given table + def table_comment(table_name) # :nodoc: + name = Utils.extract_schema_qualified_name(table_name.to_s) + return nil unless name.identifier + + select_value(<<-SQL.strip_heredoc, 'SCHEMA') + SELECT pg_catalog.obj_description(c.oid, 'pg_class') + FROM pg_catalog.pg_class c + LEFT JOIN pg_namespace n ON n.oid = c.relnamespace + WHERE c.relname = '#{name.identifier}' + AND c.relkind IN ('r') -- (r)elation/table + AND n.nspname = #{name.schema ? "'#{name.schema}'" : 'ANY (current_schemas(false))'} + SQL end # Returns the current database name. @@ -445,6 +464,7 @@ module ActiveRecord def add_column(table_name, column_name, type, options = {}) #:nodoc: clear_cache! super + change_column_comment(table_name, column_name, options[:comment]) if options.key?(:comment) end def change_column(table_name, column_name, type, options = {}) #:nodoc: @@ -466,6 +486,7 @@ module ActiveRecord change_column_default(table_name, column_name, options[:default]) if options_include_default?(options) change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null) + change_column_comment(table_name, column_name, options[:comment]) if options.key?(:comment) end # Changes the default value of a table column. @@ -494,6 +515,18 @@ module ActiveRecord execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL") end + # Adds comment for given table column or drops it if +comment+ is a +nil+ + def change_column_comment(table_name, column_name, comment) # :nodoc: + clear_cache! + execute "COMMENT ON COLUMN #{quote_table_name(table_name)}.#{quote_column_name(column_name)} IS #{quote(comment)}" + end + + # Adds comment for given table or drops it if +comment+ is a +nil+ + def change_table_comment(table_name, comment) # :nodoc: + clear_cache! + execute "COMMENT ON TABLE #{quote_table_name(table_name)} IS #{quote(comment)}" + end + # Renames a column in a table. def rename_column(table_name, column_name, new_column_name) #:nodoc: clear_cache! @@ -502,8 +535,10 @@ module ActiveRecord end def add_index(table_name, column_name, options = {}) #:nodoc: - index_name, index_type, index_columns, index_options, index_algorithm, index_using = add_index_options(table_name, column_name, options) - execute "CREATE #{index_type} INDEX #{index_algorithm} #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} #{index_using} (#{index_columns})#{index_options}" + index_name, index_type, index_columns, index_options, index_algorithm, index_using, comment = add_index_options(table_name, column_name, options) + result = execute "CREATE #{index_type} INDEX #{index_algorithm} #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} #{index_using} (#{index_columns})#{index_options}" + execute "COMMENT ON INDEX #{quote_column_name(index_name)} IS #{quote(comment)}" if comment + result # Result of execute is used in tests in activerecord/test/cases/adapters/postgresql/active_schema_test.rb end def remove_index(table_name, options = {}) #:nodoc: diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb index 6497b1cc31..cf04f32206 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb @@ -159,6 +159,10 @@ module ActiveRecord postgresql_version >= 90200 end + def supports_comments? + true + end + def index_algorithms { concurrently: 'CONCURRENTLY' } end @@ -712,7 +716,7 @@ module ActiveRecord # Returns the list of a table's column names, data types, and default values. # # The underlying query is roughly: - # SELECT column.name, column.type, default.value + # SELECT column.name, column.type, default.value, column.comment # FROM column LEFT JOIN default # ON column.table_id = default.table_id # AND column.num = default.column_num @@ -732,7 +736,8 @@ module ActiveRecord SELECT a.attname, format_type(a.atttypid, a.atttypmod), pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod, (SELECT c.collname FROM pg_collation c, pg_type t - WHERE c.oid = a.attcollation AND t.oid = a.atttypid AND a.attcollation <> t.typcollation) + WHERE c.oid = a.attcollation AND t.oid = a.atttypid AND a.attcollation <> t.typcollation), + col_description(a.attrelid, a.attnum) AS comment FROM pg_attribute a LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum WHERE a.attrelid = '#{quote_table_name(table_name)}'::regclass @@ -746,8 +751,8 @@ module ActiveRecord $1.strip if $1 end - def create_table_definition(name, temporary = false, options = nil, as = nil) # :nodoc: - PostgreSQL::TableDefinition.new(name, temporary, options, as) + def create_table_definition(name, temporary = false, options = nil, as = nil, comment = nil) # :nodoc: + PostgreSQL::TableDefinition.new(name, temporary, options, as, comment) end def can_perform_case_insensitive_comparison_for?(column) diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb index affcd9aed1..bc4adb4ed7 100644 --- a/activerecord/lib/active_record/schema_dumper.rb +++ b/activerecord/lib/active_record/schema_dumper.rb @@ -138,6 +138,9 @@ HEADER table_options = @connection.table_options(table) tbl.print ", options: #{table_options.inspect}" unless table_options.blank? + comment = @connection.table_comment(table) + tbl.print ", comment: #{comment.inspect}" if comment + tbl.puts " do |t|" # then dump all non-primary key columns @@ -209,6 +212,7 @@ HEADER statement_parts << "where: #{index.where.inspect}" if index.where statement_parts << "using: #{index.using.inspect}" if index.using statement_parts << "type: #{index.type.inspect}" if index.type + statement_parts << "comment: #{index.comment.inspect}" if index.comment " #{statement_parts.join(', ')}" end diff --git a/activerecord/test/cases/comment_test.rb b/activerecord/test/cases/comment_test.rb new file mode 100644 index 0000000000..53a490cf21 --- /dev/null +++ b/activerecord/test/cases/comment_test.rb @@ -0,0 +1,91 @@ +require 'cases/helper' +require 'support/schema_dumping_helper' + +class CommentTest < ActiveRecord::TestCase + include SchemaDumpingHelper + self.use_transactional_tests = false if current_adapter?(:Mysql2Adapter) + + class Commented < ActiveRecord::Base + self.table_name = 'commenteds' + end + + def setup + @connection = ActiveRecord::Base.connection + + @connection.transaction do + @connection.create_table('commenteds', comment: 'A table with comment', force: true) do |t| + t.string 'name', comment: 'Comment should help clarify the column purpose' + t.boolean 'obvious', comment: 'Question is: should you comment obviously named objects?' + t.string 'content' + t.index 'name', comment: %Q["Very important" index that powers all the performance.\nAnd it's fun!] + end + end + end + + teardown do + @connection.drop_table 'commenteds', if_exists: true + end + + if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter) + + def test_column_created_in_block + Commented.reset_column_information + column = Commented.columns_hash['name'] + assert_equal :string, column.type + assert_equal 'Comment should help clarify the column purpose', column.comment + end + + def test_add_column_with_comment_later + @connection.add_column :commenteds, :rating, :integer, comment: 'I am running out of imagination' + Commented.reset_column_information + column = Commented.columns_hash['rating'] + + assert_equal :integer, column.type + assert_equal 'I am running out of imagination', column.comment + end + + def test_add_index_with_comment_later + @connection.add_index :commenteds, :obvious, name: 'idx_obvious', comment: 'We need to see obvious comments' + index = @connection.indexes('commenteds').find { |idef| idef.name == 'idx_obvious' } + assert_equal 'We need to see obvious comments', index.comment + end + + def test_add_comment_to_column + @connection.change_column :commenteds, :content, :string, comment: 'Whoa, content describes itself!' + + Commented.reset_column_information + column = Commented.columns_hash['content'] + + assert_equal :string, column.type + assert_equal 'Whoa, content describes itself!', column.comment + end + + def test_remove_comment_from_column + @connection.change_column :commenteds, :obvious, :string, comment: nil + + Commented.reset_column_information + column = Commented.columns_hash['obvious'] + + assert_equal :string, column.type + assert_nil column.comment + end + + def test_schema_dump_with_comments + # Do all the stuff from other tests + @connection.add_column :commenteds, :rating, :integer, comment: 'I am running out of imagination' + @connection.change_column :commenteds, :content, :string, comment: 'Whoa, content describes itself!' + @connection.change_column :commenteds, :obvious, :string, comment: nil + @connection.add_index :commenteds, :obvious, name: 'idx_obvious', comment: 'We need to see obvious comments' + # And check that these changes are reflected in dump + output = dump_table_schema 'commenteds' + assert_match %r[create_table "commenteds",.+\s+comment: "A table with comment"], output + assert_match %r[t\.string\s+"name",\s+comment: "Comment should help clarify the column purpose"], output + assert_match %r[t\.string\s+"obvious"\n], output + assert_match %r[t\.string\s+"content",\s+comment: "Whoa, content describes itself!"], output + assert_match %r[t\.integer\s+"rating",\s+comment: "I am running out of imagination"], output + assert_match %r[add_index\s+.+\s+comment: "\\\"Very important\\\" index that powers all the performance.\\nAnd it's fun!"], output + assert_match %r[add_index\s+.+\s+name: "idx_obvious",.+\s+comment: "We need to see obvious comments"], output + end + + end +end diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md index b89485b945..c111996b58 100644 --- a/guides/source/active_record_migrations.md +++ b/guides/source/active_record_migrations.md @@ -355,6 +355,13 @@ end will append `ENGINE=BLACKHOLE` to the SQL statement used to create the table (when using MySQL or MariaDB, the default is `ENGINE=InnoDB`). +Also you can pass the `:comment` option with any description for the table +that will be stored in database itself and can be viewed with database administration +tools, such as MySQL Workbench or PgAdmin III. It's highly recommended to specify +comments in migrations for applications with large databases as it helps people +to understand data model and generate documentation. +Currently only MySQL and PostgreSQL supports comments. + ### Creating a Join Table The migration method `create_join_table` creates an HABTM (has and belongs to @@ -454,6 +461,7 @@ number of digits after the decimal point. are using a dynamic value (such as a date), the default will only be calculated the first time (i.e. on the date the migration is applied). * `index` Adds an index for the column. +* `comment` Adds a comment for the column. Some adapters may support additional options; see the adapter specific API docs for further information. |