diff options
6 files changed, 210 insertions, 38 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb index 8b94d68717..be5be0fff4 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb @@ -1,4 +1,5 @@ module ActiveRecord + # The root class of all active record objects. class Base class ConnectionSpecification #:nodoc: attr_reader :config, :adapter_method diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb index 1e8dd045f6..809424c078 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb @@ -1,11 +1,12 @@ module ActiveRecord module ConnectionAdapters # :nodoc: - # TODO: Document me! module DatabaseStatements - # Returns an array of record hashes with the column names as a keys and fields as values. + # Returns an array of record hashes with the column names as keys and + # column values as values. def select_all(sql, name = nil) end - # Returns a record hash with the column names as a keys and fields as values. + # Returns a record hash with the column names as keys and column values + # as values. def select_one(sql, name = nil) end # Returns a single value from a record @@ -21,8 +22,11 @@ module ActiveRecord result.map{ |v| v.values.first } end - # Executes the statement - def execute(sql, name = nil) end + # Executes the SQL statement in the context of this connection. + # This abstract method raises a NotImplementedError. + def execute(sql, name = nil) + raise NotImplementedError, "execute is an abstract method" + end # Returns the last auto-generated ID from the affected table. def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) end @@ -54,16 +58,23 @@ module ActiveRecord # Commits the transaction (and turns on auto-committing). def commit_db_transaction() end - # Rolls back the transaction (and turns on auto-committing). Must be done if the transaction block - # raises an exception or returns false. + # Rolls back the transaction (and turns on auto-committing). Must be + # done if the transaction block raises an exception or returns false. def rollback_db_transaction() end - def add_limit!(sql, options) #:nodoc: + # Alias for #add_limit_offset!. + def add_limit!(sql, options) return unless options add_limit_offset!(sql, options) end - def add_limit_offset!(sql, options) #:nodoc: + # Appends +LIMIT+ and +OFFSET+ options to a SQL statement. + # This method *modifies* the +sql+ parameter. + # ===== Examples + # add_limit_offset!('SELECT * FROM suppliers', {:limit => 10, :offset => 50}) + # generates + # SELECT * FROM suppliers LIMIT 10 OFFSET 50 + def add_limit_offset!(sql, options) return if options[:limit].nil? sql << " LIMIT #{options[:limit]}" sql << " OFFSET #{options[:offset]}" if options.has_key?(:offset) and !options[:offset].nil? diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb index 7f7cc03c7a..c8088bd978 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb @@ -1,7 +1,8 @@ module ActiveRecord module ConnectionAdapters # :nodoc: - # TODO: Document me! module Quoting + # Quotes the column value to help prevent + # {SQL injection attacks}[http://en.wikipedia.org/wiki/SQL_injection]. def quote(value, column = nil) case value when String @@ -22,10 +23,14 @@ module ActiveRecord end end + # Quotes a string, escaping any ' (single quote) and \ (backslash) + # characters. def quote_string(s) s.gsub(/\\/, '\&\&').gsub(/'/, "''") # ' (for ruby-mode) end + # Returns a quoted form of the column name. This is highly adapter + # specific. def quote_column_name(name) name 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 f90ac0266a..424a898db3 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb @@ -1,11 +1,15 @@ module ActiveRecord module ConnectionAdapters #:nodoc: - class Column #:nodoc: + # An abstract definition of a column in a table. + class Column attr_reader :name, :default, :type, :limit, :null - # The name should contain the name of the column, such as "name" in "name varchar(250)" - # The default should contain the type-casted default of the column, such as 1 in "count int(11) DEFAULT 1" - # The type parameter should either contain :integer, :float, :datetime, :date, :text, or :string - # The sql_type is just used for extracting the limit, such as 10 in "varchar(10)" + + # Instantiates a new column in the table. + # + # +name+ is the column's name, as in <tt><b>supplier_id</b> int(11)</tt>. + # +default+ is the type-casted default value, such as <tt>sales_stage varchar(20) default <b>'new'</b></tt>. + # +sql_type+ is only used to extract the column's length, if necessary. For example, <tt>company_name varchar(<b>60</b>)</tt>. + # +null+ determines if this column allows +NULL+ values. def initialize(name, default, sql_type = nil, null = true) @name, @type, @null = name, simplified_type(sql_type), null # have to do this one separately because type_cast depends on #type @@ -13,6 +17,7 @@ module ActiveRecord @limit = extract_limit(sql_type) unless sql_type.nil? end + # Returns the Ruby class that corresponds to the abstract data type. def klass case type when :integer then Fixnum @@ -27,6 +32,7 @@ module ActiveRecord end end + # Casts value (which is a String) to an appropriate instance. def type_cast(value) if value.nil? then return nil end case type @@ -44,14 +50,20 @@ module ActiveRecord end end + # Returns the human name of the column name. + # + # ===== Examples + # Column.new('sales_stage', ...).human_name #=> 'Sales stage' def human_name Base.human_attribute_name(@name) end + # Used to convert from Strings to BLOBs def string_to_binary(value) value end + # Used to convert from BLOBs to Strings def binary_to_string(value) value end @@ -108,7 +120,7 @@ module ActiveRecord end end end - + class IndexDefinition < Struct.new(:table, :name, :unique, :columns) #:nodoc: end @@ -130,7 +142,9 @@ module ActiveRecord end end - class TableDefinition #:nodoc: + # Represents a SQL table in an abstract way. + # Columns are stored as ColumnDefinition in the #columns attribute. + class TableDefinition attr_accessor :columns def initialize(base) @@ -138,14 +152,48 @@ module ActiveRecord @base = base end + # Appends a primary key definition to the table definition. + # Can be called multiple times, but this is probably not a good idea. def primary_key(name) column(name, native[:primary_key]) end - + + # Returns a ColumnDefinition for the column with name +name+. def [](name) @columns.find {|column| column.name == name} end + # Instantiates a new column for the table. + # The +type+ parameter must be one of the following values: + # <tt>:primary_key</tt>, <tt>:string</tt>, <tt>:text</tt>, + # <tt>:integer</tt>, <tt>:float</tt>, <tt>:datetime</tt>, + # <tt>:timestamp</tt>, <tt>:time</tt>, <tt>:date</tt>, + # <tt>:binary</tt>, <tt>:boolean</tt>. + # + # Available options are (none of these exists by default): + # * <tt>:limit</tt>: + # Requests a maximum column length (<tt>:string</tt>, <tt>:text</tt>, + # <tt>:binary</tt> or <tt>:integer</tt> columns only) + # * <tt>:default</tt>: + # The column's default value. You cannot explicitely set the default + # value to +NULL+. Simply leave off this option if you want a +NULL+ + # default value. + # * <tt>:null</tt>: + # Allows or disallows +NULL+ values in the column. This option could + # have been named <tt>:null_allowed</tt>. + # + # This method returns <tt>self</tt>. + # + # ===== Examples + # # Assuming def is an instance of TableDefinition + # def.column(:granted, :boolean) + # #=> granted BOOLEAN + # + # def.column(:picture, :binary, :limit => 2.megabytes) + # #=> picture BLOB(2097152) + # + # def.column(:sales_stage, :string, :limit => 20, :default => 'new', :null => false) + # #=> sales_stage VARCHAR(20) DEFAULT 'new' NOT NULL def column(name, type, options = {}) column = self[name] || ColumnDefinition.new(@base, name, type) column.limit = options[:limit] || native[type.to_sym][:limit] if options[:limit] or native[type.to_sym] @@ -155,6 +203,9 @@ module ActiveRecord self end + # Returns a String whose contents are the column definitions + # concatenated together. This string can then be pre and appended to + # to generate the final SQL to create the table. def to_sql @columns * ', ' end 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 d7aefc9a82..ea9173039c 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -1,8 +1,10 @@ module ActiveRecord module ConnectionAdapters # :nodoc: - # TODO: Document me! module SchemaStatements - def native_database_types #:nodoc: + # Returns a Hash of mappings from the abstract data types to the native + # database types. See TableDefinition#column for details on the recognized + # abstract data types. + def native_database_types {} end @@ -11,10 +13,67 @@ module ActiveRecord # Returns an array of indexes for the given table. # def indexes(table_name, name = nil) end - # Returns an array of column objects for the table specified by +table_name+. + # Returns an array of Column objects for the table specified by +table_name+. + # See the concrete implementation for details on the expected parameter values. def columns(table_name, name = nil) end - + # Creates a new table + # There are two ways to work with #create_table. You can use the block + # form or the regular form, like this: + # + # === Block form + # # create_table() yields a TableDefinition instance + # create_table(:suppliers) do |t| + # t.column :name, :string, :limit => 60 + # # Other fields here + # end + # + # === Regular form + # create_table(:suppliers) + # add_column(:suppliers, :name, :string, {:limit => 60}) + # + # The +options+ hash can include the following keys: + # [<tt>:id</tt>] + # Set to true or false to add/not add a primary key column + # automatically. Defaults to true. + # [<tt>:primary_key</tt>] + # The name of the primary key, if one is to be added automatically. + # Defaults to +id+. + # [<tt>:options</tt>] + # Any extra options you want appended to the table definition. + # [<tt>:temporary</tt>] + # Make a temporary table. + # + # ===== Examples + # ====== Add a backend specific option to the generated SQL (MySQL) + # create_table(:suppliers, :options => 'ENGINE=InnoDB DEFAULT CHARSET=utf8') + # generates: + # CREATE TABLE suppliers ( + # id int(11) DEFAULT NULL auto_increment PRIMARY KEY + # ) ENGINE=InnoDB DEFAULT CHARSET=utf8 + # + # ====== Rename the primary key column + # create_table(:objects, :primary_key => 'guid') do |t| + # t.column :name, :string, :limit => 80 + # end + # generates: + # CREATE TABLE objects ( + # guid int(11) DEFAULT NULL auto_increment PRIMARY KEY, + # name varchar(80) + # ) + # + # ====== Do not add a primary key column + # create_table(:categories_suppliers, :id => false) do |t| + # t.column :category_id, :integer + # t.column :supplier_id, :integer + # end + # generates: + # CREATE TABLE categories_suppliers_join ( + # category_id int, + # supplier_id int + # ) + # + # See also TableDefinition#column for details on how to create columns. def create_table(name, options = {}) table_definition = TableDefinition.new(self) table_definition.primary_key(options[:primary_key] || "id") unless options[:id] == false @@ -27,37 +86,71 @@ module ActiveRecord execute create_sql end + # Drops a table from the database. def drop_table(name) execute "DROP TABLE #{name}" end + # Adds a new column to the named table. + # See TableDefinition#column for details of the options you can use. def add_column(table_name, column_name, type, options = {}) add_column_sql = "ALTER TABLE #{table_name} ADD #{column_name} #{type_to_sql(type, options[:limit])}" add_column_options!(add_column_sql, options) execute(add_column_sql) end + # Removes the column from the table definition. + # ===== Examples + # remove_column(:suppliers, :qualification) def remove_column(table_name, column_name) execute "ALTER TABLE #{table_name} DROP #{column_name}" end + # Changes the column's definition according to the new options. + # See TableDefinition#column for details of the options you can use. + # ===== Examples + # change_column(:suppliers, :name, :string, :limit => 80) + # change_column(:accounts, :description, :text) def change_column(table_name, column_name, type, options = {}) raise NotImplementedError, "change_column is not implemented" end + # Sets a new default value for a column. If you want to set the default + # value to +NULL+, you are out of luck. You need to + # DatabaseStatements#execute the apppropriate SQL statement yourself. + # ===== Examples + # change_column_default(:suppliers, :qualification, 'new') + # change_column_default(:accounts, :authorized, 1) def change_column_default(table_name, column_name, default) raise NotImplementedError, "change_column_default is not implemented" end + # Renames a column. + # ===== Example + # rename_column(:suppliers, :description, :name) def rename_column(table_name, column_name, new_column_name) raise NotImplementedError, "rename_column is not implemented" end - # Create a new index on the given table. By default, it will be named - # <code>"#{table_name}_#{Array(column_name).first}_index"</code>, but you - # can explicitly name the index by passing <code>:name => "..."</code> - # as the last parameter. Unique indexes may be created by passing - # <code>:unique => true</code>. + # Adds a new index to the table. +column_name+ can be a single Symbol, or + # an Array of Symbols. + # + # The index will be named after the table and the first column names, + # unless you pass +:name+ as an option. + # + # ===== Examples + # ====== Creating a simple index + # add_index(:suppliers, :name) + # generates + # CREATE INDEX suppliers_name_index ON suppliers(name) + # ====== Creating a unique index + # add_index(:accounts, [:branch_id, :party_id], :unique => true) + # generates + # CREATE UNIQUE INDEX accounts_branch_id_index ON accounts(branch_id, party_id) + # ====== Creating a named index + # add_index(:accounts, [:branch_id, :party_id], :unique => true, :name => 'by_branch_party') + # generates + # CREATE UNIQUE INDEX by_branch_party ON accounts(branch_id, party_id) def add_index(table_name, column_name, options = {}) index_name = "#{table_name}_#{Array(column_name).first}_index" @@ -73,12 +166,12 @@ module ActiveRecord # Remove the given index from the table. # - # remove_index :my_table, :column => :foo - # remove_index :my_table, :name => :my_index_on_foo - # - # The first version will remove the index named - # <code>"#{my_table}_#{column}_index"</code> from the table. The - # second removes the named column from the table. + # Remove the suppliers_name_index in the suppliers table (legacy support, use the second or third forms). + # remove_index :suppliers, :name + # Remove the index named accounts_branch_id in the accounts table. + # remove_index :accounts, :column => :branch_id + # Remove the index named by_branch_party in the accounts table. + # remove_index :accounts, :name => :by_branch_party def remove_index(table_name, options = {}) if Hash === options # legacy support if options[:column] @@ -96,11 +189,14 @@ module ActiveRecord end - # Returns a string of the CREATE TABLE SQL statements for recreating the entire structure of the database. - def structure_dump #:nodoc: + # Returns a string of <tt>CREATE TABLE</tt> SQL statement(s) for recreating the + # entire structure of the database. + def structure_dump end - def initialize_schema_information #:nodoc: + # Should not be called normally, but this operation is non-destructive. + # The migrations module handles this automatically. + def initialize_schema_information begin execute "CREATE TABLE #{ActiveRecord::Migrator.schema_info_table_name} (version #{type_to_sql(:integer)})" execute "INSERT INTO #{ActiveRecord::Migrator.schema_info_table_name} (version) VALUES(0)" diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb index f6dfc4bfd4..a028cdbc00 100755 --- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb @@ -35,6 +35,12 @@ module ActiveRecord # All the concrete database adapters follow the interface laid down in this class. # You can use this interface directly by borrowing the database connection from the Base with # Base.connection. + # + # Most of the methods in the adapter are useful during migrations. Most + # notably, SchemaStatements#create_table, SchemaStatements#drop_table, + # SchemaStatements#add_index, SchemaStatements#remove_index, + # SchemaStatements#add_column, SchemaStatements#change_column and + # SchemaStatements#remove_column are very useful. class AbstractAdapter include Quoting, DatabaseStatements, SchemaStatements @@row_even = true @@ -44,12 +50,14 @@ module ActiveRecord @runtime = 0 end - # Returns the human-readable name of the adapter. Use mixed case - one can always use downcase if needed. + # Returns the human-readable name of the adapter. Use mixed case - one + # can always use downcase if needed. def adapter_name 'Abstract' end - # Returns true for database adapters that has implemented the schema statements. + # Does this adapter support migrations ? Backend specific, as the + # abstract adapter always returns +false+. def supports_migrations? false end |