OPTS | = | Sequel::OPTS | ||
AFFECTED_ROWS_RE | = | /Rows matched:\s+(\d+)\s+Changed:\s+\d+\s+Warnings:\s+\d+/.freeze | Regular expression used for getting accurate number of rows matched by an update statement. | |
DISCONNECT_ERROR_RE | = | /terminating connection due to administrator command/ |
conversion_procs | [R] | The conversion procs to use for this database |
conversion_procs | [R] | Hash of conversion procs for the current database |
convert_invalid_date_time | [R] | By default, Sequel raises an exception if in invalid date or time is used. However, if this is set to nil or :nil, the adapter treats dates like 0000-00-00 and times like 838:00:00 as nil values. If set to :string, it returns the strings as is. |
convert_tinyint_to_bool | [R] | Whether to convert tinyint columns to bool for the current database |
convert_types | [RW] | Whether to convert some Java types to ruby types when retrieving rows. True by default, can be set to false to roughly double performance when fetching rows. |
database_type | [R] | The type of database we are connecting to |
driver | [R] | The Java database driver we are using |
swift_class | [RW] | The Swift adapter class being used by this database. Connections in this database‘s connection pool will be instances of this class. |
Execute the given stored procedure with the give name. If a block is given, the stored procedure should return rows.
# File lib/sequel/adapters/jdbc.rb, line 182 182: def call_sproc(name, opts = OPTS) 183: args = opts[:args] || [] 184: sql = "{call #{name}(#{args.map{'?'}.join(',')})}" 185: synchronize(opts[:server]) do |conn| 186: cps = conn.prepareCall(sql) 187: 188: i = 0 189: args.each{|arg| set_ps_arg(cps, arg, i+=1)} 190: 191: begin 192: if block_given? 193: yield log_yield(sql){cps.executeQuery} 194: else 195: case opts[:type] 196: when :insert 197: log_yield(sql){cps.executeUpdate} 198: last_insert_id(conn, opts) 199: else 200: log_yield(sql){cps.executeUpdate} 201: end 202: end 203: rescue NativeException, JavaSQL::SQLException => e 204: raise_error(e) 205: ensure 206: cps.close 207: end 208: end 209: end
Setup a DataObjects::Connection to the database.
# File lib/sequel/adapters/do.rb, line 48 48: def connect(server) 49: setup_connection(::DataObjects::Connection.new(uri(server_opts(server)))) 50: end
Connect to the database. In addition to the usual database options, the following options have effect:
# File lib/sequel/adapters/mysql.rb, line 83 83: def connect(server) 84: opts = server_opts(server) 85: conn = Mysql.init 86: conn.options(Mysql::READ_DEFAULT_GROUP, opts[:config_default_group] || "client") 87: conn.options(Mysql::OPT_LOCAL_INFILE, opts[:config_local_infile]) if opts.has_key?(:config_local_infile) 88: conn.ssl_set(opts[:sslkey], opts[:sslcert], opts[:sslca], opts[:sslcapath], opts[:sslcipher]) if opts[:sslca] || opts[:sslkey] 89: if encoding = opts[:encoding] || opts[:charset] 90: # Set encoding before connecting so that the mysql driver knows what 91: # encoding we want to use, but this can be overridden by READ_DEFAULT_GROUP. 92: conn.options(Mysql::SET_CHARSET_NAME, encoding) 93: end 94: if read_timeout = opts[:read_timeout] and defined? Mysql::OPT_READ_TIMEOUT 95: conn.options(Mysql::OPT_READ_TIMEOUT, read_timeout) 96: end 97: if connect_timeout = opts[:connect_timeout] and defined? Mysql::OPT_CONNECT_TIMEOUT 98: conn.options(Mysql::OPT_CONNECT_TIMEOUT, connect_timeout) 99: end 100: conn.real_connect( 101: opts[:host] || 'localhost', 102: opts[:user], 103: opts[:password], 104: opts[:database], 105: (opts[:port].to_i if opts[:port]), 106: opts[:socket], 107: Mysql::CLIENT_MULTI_RESULTS + 108: Mysql::CLIENT_MULTI_STATEMENTS + 109: (opts[:compress] == false ? 0 : Mysql::CLIENT_COMPRESS) 110: ) 111: sqls = mysql_connection_setting_sqls 112: 113: # Set encoding a slightly different way after connecting, 114: # in case the READ_DEFAULT_GROUP overrode the provided encoding. 115: # Doesn't work across implicit reconnects, but Sequel doesn't turn on 116: # that feature. 117: sqls.unshift("SET NAMES #{literal(encoding.to_s)}") if encoding 118: 119: sqls.each{|sql| log_yield(sql){conn.query(sql)}} 120: 121: add_prepared_statements_cache(conn) 122: conn 123: end
Connect to the database using JavaSQL::DriverManager.getConnection.
# File lib/sequel/adapters/jdbc.rb, line 212 212: def connect(server) 213: opts = server_opts(server) 214: conn = if jndi? 215: get_connection_from_jndi 216: else 217: args = [uri(opts)] 218: args.concat([opts[:user], opts[:password]]) if opts[:user] && opts[:password] 219: begin 220: JavaSQL::DriverManager.setLoginTimeout(opts[:login_timeout]) if opts[:login_timeout] 221: JavaSQL::DriverManager.getConnection(*args) 222: rescue JavaSQL::SQLException, NativeException, StandardError => e 223: raise e unless driver 224: # If the DriverManager can't get the connection - use the connect 225: # method of the driver. (This happens under Tomcat for instance) 226: props = java.util.Properties.new 227: if opts && opts[:user] && opts[:password] 228: props.setProperty("user", opts[:user]) 229: props.setProperty("password", opts[:password]) 230: end 231: opts[:jdbc_properties].each{|k,v| props.setProperty(k.to_s, v)} if opts[:jdbc_properties] 232: begin 233: c = driver.new.connect(args[0], props) 234: raise(Sequel::DatabaseError, 'driver.new.connect returned nil: probably bad JDBC connection string') unless c 235: c 236: rescue JavaSQL::SQLException, NativeException, StandardError => e2 237: unless e2.message == e.message 238: e2.message << "\n#{e.class.name}: #{e.message}" 239: end 240: raise e2 241: end 242: end 243: end 244: setup_connection(conn) 245: end
Connect to the database. Since SQLite is a file based database, the only options available are :database (to specify the database name), and :timeout, to specify how long to wait for the database to be available if it is locked, given in milliseconds (default is 5000).
# File lib/sequel/adapters/sqlite.rb, line 98 98: def connect(server) 99: opts = server_opts(server) 100: opts[:database] = ':memory:' if blank_object?(opts[:database]) 101: db = ::SQLite3::Database.new(opts[:database]) 102: db.busy_timeout(opts.fetch(:timeout, 5000)) 103: 104: connection_pragmas.each{|s| log_yield(s){db.execute_batch(s)}} 105: 106: class << db 107: attr_reader :prepared_statements 108: end 109: db.instance_variable_set(:@prepared_statements, {}) 110: 111: db 112: end
Create an instance of swift_class for the given options.
# File lib/sequel/adapters/swift.rb, line 41 41: def connect(server) 42: opts = server_opts(server) 43: opts[:pass] = opts[:password] 44: setup_connection(swift_class.new(opts)) 45: end
Modify the type translators for the date, time, and timestamp types depending on the value given.
# File lib/sequel/adapters/mysql.rb, line 134 134: def convert_invalid_date_time=(v) 135: m0 = ::Sequel.method(:string_to_time) 136: @conversion_procs[11] = (v != false) ? lambda{|v| convert_date_time(v, &m0)} : m0 137: m1 = ::Sequel.method(:string_to_date) 138: m = (v != false) ? lambda{|v| convert_date_time(v, &m1)} : m1 139: [10, 14].each{|i| @conversion_procs[i] = m} 140: m2 = method(:to_application_timestamp) 141: m = (v != false) ? lambda{|v| convert_date_time(v, &m2)} : m2 142: [7, 12].each{|i| @conversion_procs[i] = m} 143: @convert_invalid_date_time = v 144: end
Modify the type translator used for the tinyint type based on the value given.
# File lib/sequel/adapters/mysql.rb, line 148 148: def convert_tinyint_to_bool=(v) 149: @conversion_procs[1] = TYPE_TRANSLATOR.method(v ? :boolean : :integer) 150: @convert_tinyint_to_bool = v 151: end
Close given adapter connections, and delete any related prepared statements.
# File lib/sequel/adapters/jdbc.rb, line 248 248: def disconnect_connection(c) 249: @connection_prepared_statements_mutex.synchronize{@connection_prepared_statements.delete(c)} 250: c.close 251: end
# File lib/sequel/adapters/do.rb, line 52 52: def disconnect_connection(conn) 53: conn.dispose 54: end
Closes given database connection.
# File lib/sequel/adapters/mysql.rb, line 126 126: def disconnect_connection(c) 127: c.close 128: rescue Mysql::Error 129: nil 130: end
Execute the given SQL. If a block is given, the DataObjects::Reader created is yielded to it. A block should not be provided unless a a SELECT statement is being used (or something else that returns rows). Otherwise, the return value is the insert id if opts[:type] is :insert, or the number of affected rows, otherwise.
# File lib/sequel/adapters/do.rb, line 61 61: def execute(sql, opts=OPTS) 62: synchronize(opts[:server]) do |conn| 63: begin 64: command = conn.create_command(sql) 65: res = log_yield(sql){block_given? ? command.execute_reader : command.execute_non_query} 66: rescue ::DataObjects::Error => e 67: raise_error(e) 68: end 69: if block_given? 70: begin 71: yield(res) 72: ensure 73: res.close if res 74: end 75: elsif opts[:type] == :insert 76: res.insert_id 77: else 78: res.affected_rows 79: end 80: end 81: end
Execute the given SQL, yielding a Swift::Result if a block is given.
# File lib/sequel/adapters/swift.rb, line 48 48: def execute(sql, opts=OPTS) 49: synchronize(opts[:server]) do |conn| 50: begin 51: res = log_yield(sql){conn.execute(sql)} 52: yield res if block_given? 53: nil 54: rescue ::Swift::Error => e 55: raise_error(e) 56: end 57: end 58: end
Execute the given SQL. If a block is given, if should be a SELECT statement or something else that returns rows.
# File lib/sequel/adapters/jdbc.rb, line 255 255: def execute(sql, opts=OPTS, &block) 256: return call_sproc(sql, opts, &block) if opts[:sproc] 257: return execute_prepared_statement(sql, opts, &block) if [Symbol, Dataset].any?{|c| sql.is_a?(c)} 258: synchronize(opts[:server]) do |conn| 259: statement(conn) do |stmt| 260: if block 261: yield log_yield(sql){stmt.executeQuery(sql)} 262: else 263: case opts[:type] 264: when :ddl 265: log_yield(sql){stmt.execute(sql)} 266: when :insert 267: log_yield(sql){execute_statement_insert(stmt, sql)} 268: last_insert_id(conn, opts.merge(:stmt=>stmt)) 269: else 270: log_yield(sql){stmt.executeUpdate(sql)} 271: end 272: end 273: end 274: end 275: end
Drop any prepared statements on the connection when executing DDL. This is because prepared statements lock the table in such a way that you can‘t drop or alter the table while a prepared statement that references it still exists.
# File lib/sequel/adapters/sqlite.rb, line 133 133: def execute_ddl(sql, opts=OPTS) 134: synchronize(opts[:server]) do |conn| 135: conn.prepared_statements.values.each{|cps, s| cps.close} 136: conn.prepared_statements.clear 137: super 138: end 139: end
Return the number of matched rows when executing a delete/update statement.
# File lib/sequel/adapters/mysql.rb, line 154 154: def execute_dui(sql, opts=OPTS) 155: execute(sql, opts){|c| return affected_rows(c)} 156: end
Execute the SQL on the this database, returning the number of affected rows.
# File lib/sequel/adapters/swift.rb, line 62 62: def execute_dui(sql, opts=OPTS) 63: synchronize(opts[:server]) do |conn| 64: begin 65: log_yield(sql){conn.execute(sql).affected_rows} 66: rescue ::Swift::Error => e 67: raise_error(e) 68: end 69: end 70: end
Execute the SQL on this database, returning the primary key of the table being inserted to.
# File lib/sequel/adapters/swift.rb, line 74 74: def execute_insert(sql, opts=OPTS) 75: synchronize(opts[:server]) do |conn| 76: begin 77: log_yield(sql){conn.execute(sql).insert_id} 78: rescue ::Swift::Error => e 79: raise_error(e) 80: end 81: end 82: end
Return the last inserted id when executing an insert statement.
# File lib/sequel/adapters/mysql.rb, line 159 159: def execute_insert(sql, opts=OPTS) 160: execute(sql, opts){|c| return c.insert_id} 161: end
Use the JDBC metadata to get the index information for the table.
# File lib/sequel/adapters/jdbc.rb, line 291 291: def indexes(table, opts=OPTS) 292: m = output_identifier_meth 293: im = input_identifier_meth 294: schema, table = schema_and_table(table) 295: schema ||= opts[:schema] 296: schema = im.call(schema) if schema 297: table = im.call(table) 298: indexes = {} 299: metadata(:getIndexInfo, nil, schema, table, false, true) do |r| 300: next unless name = r[:column_name] 301: next if respond_to?(:primary_key_index_re, true) and r[:index_name] =~ primary_key_index_re 302: i = indexes[m.call(r[:index_name])] ||= {:columns=>[], :unique=>[false, 0].include?(r[:non_unique])} 303: i[:columns] << m.call(name) 304: end 305: indexes 306: end
Whether or not JNDI is being used for this connection.
# File lib/sequel/adapters/jdbc.rb, line 309 309: def jndi? 310: !!(uri =~ JNDI_URI_REGEXP) 311: end
Return the subadapter type for this database, i.e. sqlite3 for do:sqlite3::memory:.
# File lib/sequel/adapters/do.rb, line 97 97: def subadapter 98: uri.split(":").first 99: end
Handle Integer and Float arguments, since SQLite can store timestamps as integers and floats.
# File lib/sequel/adapters/sqlite.rb, line 147 147: def to_application_timestamp(s) 148: case s 149: when String 150: super 151: when Integer 152: super(Time.at(s).to_s) 153: when Float 154: super(DateTime.jd(s).to_s) 155: else 156: raise Sequel::Error, "unhandled type when converting to : #{s.inspect} (#{s.class.inspect})" 157: end 158: end
The uri for this connection. You can specify the uri using the :uri, :url, or :database options. You don‘t need to worry about this if you use Sequel.connect with the JDBC connectrion strings.
# File lib/sequel/adapters/jdbc.rb, line 322 322: def uri(opts=OPTS) 323: opts = @opts.merge(opts) 324: ur = opts[:uri] || opts[:url] || opts[:database] 325: ur =~ /^\Ajdbc:/ ? ur : "jdbc:#{ur}" 326: end
Return the DataObjects URI for the Sequel URI, removing the do: prefix.
# File lib/sequel/adapters/do.rb, line 103 103: def uri(opts=OPTS) 104: opts = @opts.merge(opts) 105: (opts[:uri] || opts[:url]).sub(/\Ado:/, '') 106: end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/features.rb, line 17 17: def supports_create_table_if_not_exists? 18: false 19: end
Whether the database supports deferrable constraints, false by default as few databases do.
# File lib/sequel/database/features.rb, line 23 23: def supports_deferrable_constraints? 24: false 25: end
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
# File lib/sequel/database/features.rb, line 29 29: def supports_deferrable_foreign_key_constraints? 30: supports_deferrable_constraints? 31: end
Whether the database supports DROP TABLE IF EXISTS syntax, default is the same as supports_create_table_if_not_exists?.
# File lib/sequel/database/features.rb, line 35 35: def supports_drop_table_if_exists? 36: supports_create_table_if_not_exists? 37: end
Whether the database supports Database#foreign_key_list for parsing foreign keys.
# File lib/sequel/database/features.rb, line 41 41: def supports_foreign_key_parsing? 42: respond_to?(:foreign_key_list) 43: end
Whether the database supports Database#indexes for parsing indexes.
# File lib/sequel/database/features.rb, line 46 46: def supports_index_parsing? 47: respond_to?(:indexes) 48: end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb, line 52 52: def supports_prepared_transactions? 53: false 54: end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb, line 57 57: def supports_savepoints? 58: false 59: end
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), default is false.
# File lib/sequel/database/features.rb, line 63 63: def supports_savepoints_in_prepared_transactions? 64: supports_prepared_transactions? && supports_savepoints? 65: end
Whether the database supports schema parsing via Database#schema.
# File lib/sequel/database/features.rb, line 68 68: def supports_schema_parsing? 69: respond_to?(:schema_parse_table, true) 70: end
Whether the database supports Database#tables for getting list of tables.
# File lib/sequel/database/features.rb, line 73 73: def supports_table_listing? 74: respond_to?(:tables) 75: end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/features.rb, line 83 83: def supports_transaction_isolation_levels? 84: false 85: end
Whether DDL statements work correctly in transactions, false by default.
# File lib/sequel/database/features.rb, line 88 88: def supports_transactional_ddl? 89: false 90: end
Whether the database supports Database#views for getting list of views.
# File lib/sequel/database/features.rb, line 78 78: def supports_view_listing? 79: respond_to?(:views) 80: end
This methods change the default behavior of this database‘s datasets.
DatasetClass | = | Sequel::Dataset | The default class to use for datasets |
dataset_class | [R] | The class to use for creating datasets. Should respond to new with the Database argument as the first argument, and an optional options hash. |
identifier_input_method | [R] | The identifier input method to use by default for all databases (default: adapter default) |
identifier_input_method | [R] | The identifier input method to use by default for this database (default: adapter default) |
identifier_output_method | [R] | The identifier output method to use by default for all databases (default: adapter default) |
identifier_output_method | [R] | The identifier output method to use by default for this database (default: adapter default) |
quote_identifiers | [RW] | Whether to quote identifiers (columns and tables) by default for all databases (default: adapter default) |
Change the default identifier input method to use for all databases,
# File lib/sequel/database/dataset_defaults.rb, line 27 27: def self.identifier_input_method=(v) 28: @identifier_input_method = v.nil? ? false : v 29: end
Change the default identifier output method to use for all databases,
# File lib/sequel/database/dataset_defaults.rb, line 32 32: def self.identifier_output_method=(v) 33: @identifier_output_method = v.nil? ? false : v 34: end
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb, line 50 50: def dataset_class=(c) 51: unless @dataset_modules.empty? 52: c = Class.new(c) 53: @dataset_modules.each{|m| c.send(:include, m)} 54: end 55: @dataset_class = c 56: reset_default_dataset 57: end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class as the new dataset_class, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database object uses.
Examples:
# Introspec columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end
# File lib/sequel/database/dataset_defaults.rb, line 81 81: def extend_datasets(mod=nil, &block) 82: raise(Error, "must provide either mod or block, not both") if mod && block 83: mod = Module.new(&block) if block 84: if @dataset_modules.empty? 85: @dataset_modules = [mod] 86: @dataset_class = Class.new(@dataset_class) 87: else 88: @dataset_modules << mod 89: end 90: @dataset_class.send(:include, mod) 91: reset_default_dataset 92: end
Set the method to call on identifiers going into the database:
DB[:items] # SELECT * FROM items DB.identifier_input_method = :upcase DB[:items] # SELECT * FROM ITEMS
# File lib/sequel/database/dataset_defaults.rb, line 99 99: def identifier_input_method=(v) 100: reset_default_dataset 101: @identifier_input_method = v 102: end
Set the method to call on identifiers coming from the database:
DB[:items].first # {:id=>1, :name=>'foo'} DB.identifier_output_method = :upcase DB[:items].first # {:ID=>1, :NAME=>'foo'}
# File lib/sequel/database/dataset_defaults.rb, line 109 109: def identifier_output_method=(v) 110: reset_default_dataset 111: @identifier_output_method = v 112: end
Set whether to quote identifiers (columns and tables) for this database:
DB[:items] # SELECT * FROM items DB.quote_identifiers = true DB[:items] # SELECT * FROM "items"
# File lib/sequel/database/dataset_defaults.rb, line 119 119: def quote_identifiers=(v) 120: reset_default_dataset 121: @quote_identifiers = v 122: end
These methods don‘t fit neatly into another category.
EXTENSIONS | = | {} | Hash of extension name symbols to callable objects to load the extension into the Database object (usually by extending it with a module defined in the extension). | |
DEFAULT_STRING_COLUMN_SIZE | = | 255 | The general default size for string columns for all Sequel::Database instances. | |
DEFAULT_DATABASE_ERROR_REGEXPS | = | {}.freeze | Empty exception regexp to class map, used by default if Sequel doesn‘t have specific support for the database in use. | |
SCHEMA_TYPE_CLASSES | = | {:string=>String, :integer=>Integer, :date=>Date, :datetime=>[Time, DateTime].freeze, :time=>Sequel::SQLTime, :boolean=>[TrueClass, FalseClass].freeze, :float=>Float, :decimal=>BigDecimal, :blob=>Sequel::SQL::Blob}.freeze | Mapping of schema type symbols to class or arrays of classes for that symbol. | |
NOT_NULL_CONSTRAINT_SQLSTATES | = | %w'23502'.freeze.each{|s| s.freeze} | ||
FOREIGN_KEY_CONSTRAINT_SQLSTATES | = | %w'23503 23506 23504'.freeze.each{|s| s.freeze} | ||
UNIQUE_CONSTRAINT_SQLSTATES | = | %w'23505'.freeze.each{|s| s.freeze} | ||
CHECK_CONSTRAINT_SQLSTATES | = | %w'23513 23514'.freeze.each{|s| s.freeze} | ||
SERIALIZATION_CONSTRAINT_SQLSTATES | = | %w'40001'.freeze.each{|s| s.freeze} | ||
LEADING_ZERO_RE | = | /\A0+(\d)/.freeze | Used for checking/removing leading zeroes from strings so they don‘t get interpreted as octal. | |
LEADING_ZERO_REP | = | "\\1".freeze | :nocov: Replacement string when replacing leading zeroes. |
default_string_column_size | [RW] | The specific default size of string columns for this Sequel::Database, usually 255 by default. |
opts | [R] | The options hash for this database |
timezone | [W] | Set the timezone to use for this database, overridding Sequel.database_timezone. |
Register a hook that will be run when a new Database is instantiated. It is called with the new database handle.
# File lib/sequel/database/misc.rb, line 40 40: def self.after_initialize(&block) 41: raise Error, "must provide block to after_initialize" unless block 42: Sequel.synchronize do 43: previous = @initialize_hook 44: @initialize_hook = Proc.new do |db| 45: previous.call(db) 46: block.call(db) 47: end 48: end 49: end
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
:default_string_column_size : | The default size of string columns, 255 by default. |
:identifier_input_method : | A string method symbol to call on identifiers going into the database |
:identifier_output_method : | A string method symbol to call on identifiers coming from the database |
:logger : | A specific logger to use |
:loggers : | An array of loggers to use |
:quote_identifiers : | Whether to quote identifiers |
:servers : | A hash specifying a server/shard specific options, keyed by shard symbol |
:single_threaded : | Whether to use a single-threaded connection pool |
:sql_log_level : | Method to use to log SQL to a logger, :info by default. |
All options given are also passed to the connection pool.
# File lib/sequel/database/misc.rb, line 113 113: def initialize(opts = OPTS, &block) 114: @opts ||= opts 115: @opts = connection_pool_default_options.merge(@opts) 116: @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) 117: self.log_warn_duration = @opts[:log_warn_duration] 118: block ||= proc{|server| connect(server)} 119: @opts[:servers] = {} if @opts[:servers].is_a?(String) 120: @opts[:adapter_class] = self.class 121: 122: @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Database.single_threaded)) 123: @schemas = {} 124: @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE 125: @prepared_statements = {} 126: @transactions = {} 127: @identifier_input_method = nil 128: @identifier_output_method = nil 129: @quote_identifiers = nil 130: @timezone = nil 131: @dataset_class = dataset_class_default 132: @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) 133: @dataset_modules = [] 134: @schema_type_classes = SCHEMA_TYPE_CLASSES.dup 135: self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info 136: @pool = ConnectionPool.get_pool(self, @opts) 137: 138: reset_identifier_mangling 139: adapter_initialize 140: 141: unless typecast_value_boolean(@opts[:keep_reference]) == false 142: Sequel.synchronize{::Sequel::DATABASES.push(self)} 143: end 144: Sequel::Database.run_after_initialize(self) 145: end
Register an extension callback for Database objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
# File lib/sequel/database/misc.rb, line 61 61: def self.register_extension(ext, mod=nil, &block) 62: if mod 63: raise(Error, "cannot provide both mod and block to Database.register_extension") if block 64: if mod.is_a?(Module) 65: block = proc{|db| db.extend(mod)} 66: else 67: block = mod 68: end 69: end 70: Sequel.synchronize{EXTENSIONS[ext] = block} 71: end
Run the after_initialize hook for the given instance.
# File lib/sequel/database/misc.rb, line 74 74: def self.run_after_initialize(instance) 75: @initialize_hook.call(instance) 76: end
If a transaction is not currently in process, yield to the block immediately. Otherwise, add the block to the list of blocks to call after the currently in progress transaction commits (and only if it commits). Options:
:server : | The server/shard to use. |
# File lib/sequel/database/misc.rb, line 152 152: def after_commit(opts=OPTS, &block) 153: raise Error, "must provide block to after_commit" unless block 154: synchronize(opts[:server]) do |conn| 155: if h = _trans(conn) 156: raise Error, "cannot call after_commit in a prepared transaction" if h[:prepare] 157: (h[:after_commit] ||= []) << block 158: else 159: yield 160: end 161: end 162: end
If a transaction is not currently in progress, ignore the block. Otherwise, add the block to the list of the blocks to call after the currently in progress transaction rolls back (and only if it rolls back). Options:
:server : | The server/shard to use. |
# File lib/sequel/database/misc.rb, line 169 169: def after_rollback(opts=OPTS, &block) 170: raise Error, "must provide block to after_rollback" unless block 171: synchronize(opts[:server]) do |conn| 172: if h = _trans(conn) 173: raise Error, "cannot call after_rollback in a prepared transaction" if h[:prepare] 174: (h[:after_rollback] ||= []) << block 175: end 176: end 177: end
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database objects, an Error will be raised. Returns self.
# File lib/sequel/database/misc.rb, line 192 192: def extension(*exts) 193: Sequel.extension(*exts) 194: exts.each do |ext| 195: if pr = Sequel.synchronize{EXTENSIONS[ext]} 196: pr.call(self) 197: else 198: raise(Error, "Extension #{ext} does not have specific support handling individual databases") 199: end 200: end 201: self 202: end
Convert the given timestamp from the application‘s timezone, to the databases‘s timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb, line 207 207: def from_application_timestamp(v) 208: Sequel.convert_output_timestamp(v, timezone) 209: end
Return true if already in a transaction given the options, false otherwise. Respects the :server option for selecting a shard.
# File lib/sequel/database/misc.rb, line 214 214: def in_transaction?(opts=OPTS) 215: synchronize(opts[:server]){|conn| !!_trans(conn)} 216: end
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
# File lib/sequel/database/misc.rb, line 220 220: def inspect 221: a = [] 222: a << uri.inspect if uri 223: if (oo = opts[:orig_opts]) && !oo.empty? 224: a << oo.inspect 225: end 226: "#<#{self.class}: #{a.join(' ')}>" 227: end
Synchronize access to the prepared statements cache.
# File lib/sequel/database/misc.rb, line 239 239: def prepared_statement(name) 240: Sequel.synchronize{prepared_statements[name]} 241: end
Proxy the quote_identifier method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
# File lib/sequel/database/misc.rb, line 246 246: def quote_identifier(v) 247: schema_utility_dataset.quote_identifier(v) 248: end
Return ruby class or array of classes for the given type symbol.
# File lib/sequel/database/misc.rb, line 251 251: def schema_type_class(type) 252: @schema_type_classes[type] 253: end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb, line 257 257: def serial_primary_key_options 258: {:primary_key => true, :type => Integer, :auto_increment => true} 259: end
Cache the prepared statement object at the given name.
# File lib/sequel/database/misc.rb, line 262 262: def set_prepared_statement(name, ps) 263: ps.prepared_sql 264: Sequel.synchronize{prepared_statements[name] = ps} 265: end
Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
# File lib/sequel/database/misc.rb, line 284 284: def typecast_value(column_type, value) 285: return nil if value.nil? 286: meth = "typecast_value_#{column_type}" 287: begin 288: respond_to?(meth, true) ? send(meth, value) : value 289: rescue ArgumentError, TypeError => e 290: raise Sequel.convert_exception_class(e, InvalidValue) 291: end 292: end
Database transactions make multiple queries atomic, so that either all of the queries take effect or none of them do.
SQL_BEGIN | = | 'BEGIN'.freeze |
SQL_COMMIT | = | 'COMMIT'.freeze |
SQL_RELEASE_SAVEPOINT | = | 'RELEASE SAVEPOINT autopoint_%d'.freeze |
SQL_ROLLBACK | = | 'ROLLBACK'.freeze |
SQL_ROLLBACK_TO_SAVEPOINT | = | 'ROLLBACK TO SAVEPOINT autopoint_%d'.freeze |
SQL_SAVEPOINT | = | 'SAVEPOINT autopoint_%d'.freeze |
TRANSACTION_BEGIN | = | 'Transaction.begin'.freeze |
TRANSACTION_COMMIT | = | 'Transaction.commit'.freeze |
TRANSACTION_ROLLBACK | = | 'Transaction.rollback'.freeze |
TRANSACTION_ISOLATION_LEVELS | = | {:uncommitted=>'READ UNCOMMITTED'.freeze, :committed=>'READ COMMITTED'.freeze, :repeatable=>'REPEATABLE READ'.freeze, :serializable=>'SERIALIZABLE'.freeze} |
transaction_isolation_level | [RW] | The default transaction isolation level for this database, used for all future transactions. For MSSQL, this should be set to something if you ever plan to use the :isolation option to Database#transaction, as on MSSQL if affects all future transactions on the same connection. |
Starts a database transaction. When a database transaction is used, either all statements are successful or none of the statements are successful. Note that MySQL MyISAM tables do not support transactions.
The following general options are respected:
:isolation : | The transaction isolation level to use for this transaction, should be :uncommitted, :committed, :repeatable, or :serializable, used if given and the database/adapter supports customizable transaction isolation levels. |
:num_retries : | The number of times to retry if the :retry_on option is used. The default is 5 times. Can be set to nil to retry indefinitely, but that is not recommended. |
:prepare : | A string to use as the transaction identifier for a prepared transaction (two-phase commit), if the database/adapter supports prepared transactions. |
:retry_on : | An exception class or array of exception classes for which to automatically retry the transaction. Can only be set if not inside an existing transaction. Note that this should not be used unless the entire transaction block is idempotent, as otherwise it can cause non-idempotent behavior to execute multiple times. |
:rollback : | Can the set to :reraise to reraise any Sequel::Rollback exceptions raised, or :always to always rollback even if no exceptions occur (useful for testing). |
:server : | The server to use for the transaction. |
:savepoint : | Whether to create a new savepoint for this transaction, only respected if the database/adapter supports savepoints. By default Sequel will reuse an existing transaction, so if you want to use a savepoint you must use this option. |
PostgreSQL specific options:
:deferrable : | (9.1+) If present, set to DEFERRABLE if true or NOT DEFERRABLE if false. |
:read_only : | If present, set to READ ONLY if true or READ WRITE if false. |
:synchronous : | if non-nil, set synchronous_commit appropriately. Valid values true, :on, false, :off, :local (9.1+), and :remote_write (9.2+). |
# File lib/sequel/database/transactions.rb, line 71 71: def transaction(opts=OPTS, &block) 72: if retry_on = opts[:retry_on] 73: num_retries = opts.fetch(:num_retries, 5) 74: begin 75: transaction(opts.merge(:retry_on=>nil, :retrying=>true), &block) 76: rescue *retry_on 77: if num_retries 78: num_retries -= 1 79: retry if num_retries >= 0 80: else 81: retry 82: end 83: raise 84: end 85: else 86: synchronize(opts[:server]) do |conn| 87: if already_in_transaction?(conn, opts) 88: if opts[:retrying] 89: raise Sequel::Error, "cannot set :retry_on options if you are already inside a transaction" 90: end 91: return yield(conn) 92: end 93: _transaction(conn, opts, &block) 94: end 95: end 96: end
This methods affect relating to the logging of executed SQL.
log_warn_duration | [RW] | Numeric specifying the duration beyond which queries are logged at warn level instead of info level. |
loggers | [RW] | Array of SQL loggers to use for this database. |
sql_log_level | [RW] | Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level. |
Log a message at error level, with information about the exception.
# File lib/sequel/database/logging.rb, line 21 21: def log_exception(exception, message) 22: log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}") 23: end
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb, line 26 26: def log_info(message, args=nil) 27: log_each(:info, args ? "#{message}; #{args.inspect}" : message) 28: end
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb, line 32 32: def log_yield(sql, args=nil) 33: return yield if @loggers.empty? 34: sql = "#{sql}; #{args.inspect}" if args 35: start = Time.now 36: begin 37: yield 38: rescue => e 39: log_exception(e, sql) 40: raise 41: ensure 42: log_duration(Time.now - start, sql) unless e 43: end 44: end
This methods involve the Database‘s connection pool.
ADAPTERS | = | %w'ado amalgalite cubrid db2 dbi do firebird ibmdb informix jdbc mock mysql mysql2 odbc openbase oracle postgres sqlite swift tinytds'.collect{|x| x.to_sym} | Array of supported database adapters |
The Database subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb, line 21 21: def self.adapter_class(scheme) 22: return scheme if scheme.is_a?(Class) 23: 24: scheme = scheme.to_s.gsub('-', '_').to_sym 25: 26: unless klass = ADAPTER_MAP[scheme] 27: # attempt to load the adapter file 28: begin 29: require "sequel/adapters/#{scheme}" 30: rescue LoadError => e 31: raise Sequel.convert_exception_class(e, AdapterNotFound) 32: end 33: 34: # make sure we actually loaded the adapter 35: unless klass = ADAPTER_MAP[scheme] 36: raise AdapterNotFound, "Could not load #{scheme} adapter: adapter class not registered in ADAPTER_MAP" 37: end 38: end 39: klass 40: end
Connects to a database. See Sequel.connect.
# File lib/sequel/database/connecting.rb, line 48 48: def self.connect(conn_string, opts = OPTS) 49: case conn_string 50: when String 51: if match = /\A(jdbc|do):/o.match(conn_string) 52: c = adapter_class(match[1].to_sym) 53: opts = opts.merge(:orig_opts=>opts.dup) 54: opts = {:uri=>conn_string}.merge(opts) 55: else 56: uri = URI.parse(conn_string) 57: scheme = uri.scheme 58: scheme = :dbi if scheme =~ /\Adbi-/ 59: c = adapter_class(scheme) 60: uri_options = c.send(:uri_to_options, uri) 61: uri.query.split('&').collect{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? 62: uri_options.to_a.each{|k,v| uri_options[k] = (defined?(URI::DEFAULT_PARSER) ? URI::DEFAULT_PARSER : URI).unescape(v) if v.is_a?(String)} 63: opts = uri_options.merge(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) 64: end 65: when Hash 66: opts = conn_string.merge(opts) 67: opts = opts.merge(:orig_opts=>opts.dup) 68: c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) 69: else 70: raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" 71: end 72: # process opts a bit 73: opts = opts.inject({}) do |m, (k,v)| 74: k = :user if k.to_s == 'username' 75: m[k.to_sym] = v 76: m 77: end 78: begin 79: db = c.new(opts) 80: db.test_connection if opts[:test] && db.send(:typecast_value_boolean, opts[:test]) 81: if block_given? 82: return yield(db) 83: end 84: ensure 85: if block_given? 86: db.disconnect if db 87: Sequel.synchronize{::Sequel::DATABASES.delete(db)} 88: end 89: end 90: db 91: end
Returns the scheme symbol for this instance‘s class, which reflects which adapter is being used. In some cases, this can be the same as the database_type (for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb, line 121 121: def adapter_scheme 122: self.class.adapter_scheme 123: end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Intended for use with master/slave or shard configurations where it is useful to add new server hosts at runtime.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it‘s value is overridden with the value provided.
DB.add_servers(:f=>{:host=>"hash_host_f"})
# File lib/sequel/database/connecting.rb, line 134 134: def add_servers(servers) 135: if h = @opts[:servers] 136: Sequel.synchronize{h.merge!(servers)} 137: @pool.add_servers(servers.keys) 138: end 139: end
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database objects that are using the same adapter are connecting to different database types (think JDBC or DataObjects).
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb, line 150 150: def database_type 151: adapter_scheme 152: end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
:servers : | Should be a symbol specifing the server to disconnect from, or an array of symbols to specify multiple servers. |
Example:
DB.disconnect # All servers DB.disconnect(:servers=>:server1) # Single server DB.disconnect(:servers=>[:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb, line 164 164: def disconnect(opts = OPTS) 165: pool.disconnect(opts) 166: end
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
# File lib/sequel/database/connecting.rb, line 171 171: def disconnect_connection(conn) 172: conn.close 173: end
Yield a new Database instance for every server in the connection pool. Intended for use in sharded environments where there is a need to make schema modifications (DDL queries) on each shard.
DB.each_server{|db| db.create_table(:users){primary_key :id; String :name}}
# File lib/sequel/database/connecting.rb, line 180 180: def each_server(&block) 181: raise(Error, "Database#each_server must be passed a block") unless block 182: servers.each{|s| self.class.connect(server_opts(s), &block)} 183: end
Dynamically remove existing servers from the connection pool. Intended for use with master/slave or shard configurations where it is useful to remove existing server hosts at runtime.
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb, line 195 195: def remove_servers(*servers) 196: if h = @opts[:servers] 197: servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} 198: @pool.remove_servers(servers) 199: end 200: end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb, line 211 211: def single_threaded? 212: @single_threaded 213: end
Acquires a database connection, yielding it to the passed block. This is useful if you want to make sure the same connection is used for all database queries in the block. It is also useful if you want to gain direct access to the underlying connection object if you need to do something Sequel does not natively support.
If a server option is given, acquires a connection for that specific server, instead of the :default server.
DB.synchronize do |conn| ... end
# File lib/sequel/database/connecting.rb, line 228 228: def synchronize(server=nil) 229: @pool.hold(server || :default){|conn| yield conn} 230: end
:nocov:
# File lib/sequel/database/connecting.rb, line 233 233: def synchronize(server=nil, &block) 234: @pool.hold(server || :default, &block) 235: end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb, line 243 243: def test_connection(server=nil) 244: synchronize(server){|conn|} 245: true 246: end
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
# File lib/sequel/database/connecting.rb, line 252 252: def valid_connection?(conn) 253: sql = valid_connection_sql 254: begin 255: log_connection_execute(conn, sql) 256: rescue Sequel::DatabaseError, *database_error_classes 257: false 258: else 259: true 260: end 261: end
AUTOINCREMENT | = | 'AUTOINCREMENT'.freeze | ||
COMMA_SEPARATOR | = | ', '.freeze | ||
NOT_NULL | = | ' NOT NULL'.freeze | ||
NULL | = | ' NULL'.freeze | ||
PRIMARY_KEY | = | ' PRIMARY KEY'.freeze | ||
TEMPORARY | = | 'TEMPORARY '.freeze | ||
UNDERSCORE | = | '_'.freeze | ||
UNIQUE | = | ' UNIQUE'.freeze | ||
UNSIGNED | = | ' UNSIGNED'.freeze | ||
COLUMN_DEFINITION_ORDER | = | [:collate, :default, :null, :unique, :primary_key, :auto_increment, :references] | The order of column modifiers to use when defining a column. | |
DEFAULT_JOIN_TABLE_COLUMN_OPTIONS | = | {:null=>false} | The default options for join table columns. | |
COMBINABLE_ALTER_TABLE_OPS | = | [:add_column, :drop_column, :rename_column, :set_column_type, :set_column_default, :set_column_null, :add_constraint, :drop_constraint] | The alter table operations that are combinable. |
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, :text, :unique => true, :null => false DB.add_column :items, :category, :text, :default => 'ruby'
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 36 36: def add_column(table, *args) 37: alter_table(table) {add_column(*args)} 38: end
Adds an index to a table for the given columns:
DB.add_index :posts, :title DB.add_index :posts, [:author, :title], :unique => true
Options:
:ignore_errors : | Ignore any DatabaseErrors that are raised |
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 49 49: def add_index(table, columns, options=OPTS) 50: e = options[:ignore_errors] 51: begin 52: alter_table(table){add_index(columns, options)} 53: rescue DatabaseError 54: raise unless e 55: end 56: end
Alters the given table with the specified block. Example:
DB.alter_table :items do add_column :category, :text, :default => 'ruby' drop_column :category rename_column :cntr, :counter set_column_type :value, :float set_column_default :value, :float add_index [:group, :category] drop_index [:group, :category] end
Note that add_column accepts all the options available for column definitions using create_table, and add_index accepts all the options available for index definition.
See Schema::AlterTableGenerator and the "Migrations and Schema Modification" guide.
# File lib/sequel/database/schema_methods.rb, line 75 75: def alter_table(name, generator=nil, &block) 76: generator ||= alter_table_generator(&block) 77: remove_cached_schema(name) 78: apply_alter_table_generator(name, generator) 79: nil 80: end
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb, line 84 84: def alter_table_generator(&block) 85: alter_table_generator_class.new(self, &block) 86: end
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(:cat_id=>:cats, :dog_id=>:dogs) # CREATE TABLE cats_dogs ( # cat_id integer NOT NULL REFERENCES cats, # dog_id integer NOT NULL REFERENCES dogs, # PRIMARY KEY (cat_id, dog_id) # ) # CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(:cat_id=>{:table=>:cats, :type=>Bignum}, :dog_id=>:dogs)
You can provide a second argument which is a table options hash:
create_join_table({:cat_id=>:cats, :dog_id=>:dogs}, :temp=>true)
Some table options are handled specially:
:index_options : | The options to pass to the index |
:name : | The name of the table to create |
:no_index : | Set to true not to create the second index. |
:no_primary_key : | Set to true to not create the primary key. |
# File lib/sequel/database/schema_methods.rb, line 120 120: def create_join_table(hash, options=OPTS) 121: keys = hash.keys.sort_by{|k| k.to_s} 122: create_table(join_table_name(hash, options), options) do 123: keys.each do |key| 124: v = hash[key] 125: unless v.is_a?(Hash) 126: v = {:table=>v} 127: end 128: v = DEFAULT_JOIN_TABLE_COLUMN_OPTIONS.merge(v) 129: foreign_key(key, v) 130: end 131: primary_key(keys) unless options[:no_primary_key] 132: index(keys.reverse, options[:index_options] || {}) unless options[:no_index] 133: end 134: end
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100") DB.create_or_replace_view(:some_items, DB[:items].filter(:category => 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
# File lib/sequel/database/schema_methods.rb, line 214 214: def create_or_replace_view(name, source, options = OPTS) 215: if supports_create_or_replace_view? 216: options = options.merge(:replace=>true) 217: else 218: drop_view(name) rescue nil 219: end 220: 221: create_view(name, source, options) 222: end
Creates a table with the columns given in the provided block:
DB.create_table :posts do primary_key :id column :title, :text String :content index :title end
General options:
:as : | Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method. |
:ignore_index_errors : | Ignore any errors when creating indexes. |
:temp : | Create the table as a temporary table. |
MySQL specific options:
:charset : | The character set to use for the table. |
:collate : | The collation to use for the table. |
:engine : | The table engine to use for the table. |
PostgreSQL specific options:
:unlogged : | Create the table as an unlogged table. |
:inherits : | Inherit from a different tables. An array can be specified to inherit from multiple tables. |
See Schema::Generator and the "Schema Modification" guide.
# File lib/sequel/database/schema_methods.rb, line 163 163: def create_table(name, options=OPTS, &block) 164: remove_cached_schema(name) 165: options = {:generator=>options} if options.is_a?(Schema::CreateTableGenerator) 166: if sql = options[:as] 167: raise(Error, "can't provide both :as option and block to create_table") if block 168: create_table_as(name, sql, options) 169: else 170: generator = options[:generator] || create_table_generator(&block) 171: create_table_from_generator(name, generator, options) 172: create_table_indexes_from_generator(name, generator, options) 173: nil 174: end 175: end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb, line 183 183: def create_table!(name, options=OPTS, &block) 184: drop_table?(name) 185: create_table(name, options, &block) 186: end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb, line 193 193: def create_table?(name, options=OPTS, &block) 194: if supports_create_table_if_not_exists? 195: create_table(name, options.merge(:if_not_exists=>true), &block) 196: elsif !table_exists?(name) 197: create_table(name, options, &block) 198: end 199: end
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb, line 203 203: def create_table_generator(&block) 204: create_table_generator_class.new(self, &block) 205: end
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100") DB.create_view(:ruby_items, DB[:items].filter(:category => 'ruby'))
Options:
:columns : | The column names to use for the view. If not given, automatically determined based on the input dataset. |
PostgreSQL/SQLite specific option:
:temp : | Create a temporary view, automatically dropped on disconnect. |
PostgreSQL specific option:
:materialized : | Creates a materialized view, similar to a regular view, but backed by a physical table. |
:recursive : | Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn‘t in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the :all=>true and :from_self=>false options. |
# File lib/sequel/database/schema_methods.rb, line 245 245: def create_view(name, source, options = OPTS) 246: execute_ddl(create_view_sql(name, source, options)) 247: remove_cached_schema(name) 248: nil 249: end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 256 256: def drop_column(table, *args) 257: alter_table(table) {drop_column(*args)} 258: end
Removes an index for the given table and column/s:
DB.drop_index :posts, :title DB.drop_index :posts, [:author, :title]
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 266 266: def drop_index(table, columns, options=OPTS) 267: alter_table(table){drop_index(columns, options)} 268: end
Drop the join table that would have been created with the same arguments to create_join_table:
drop_join_table(:cat_id=>:cats, :dog_id=>:dogs) # DROP TABLE cats_dogs
# File lib/sequel/database/schema_methods.rb, line 275 275: def drop_join_table(hash, options=OPTS) 276: drop_table(join_table_name(hash, options), options) 277: end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, :cascade=>true)
# File lib/sequel/database/schema_methods.rb, line 284 284: def drop_table(*names) 285: options = names.last.is_a?(Hash) ? names.pop : {} 286: names.each do |n| 287: execute_ddl(drop_table_sql(n, options)) 288: remove_cached_schema(n) 289: end 290: nil 291: end
Drops the table if it already exists. If it doesn‘t exist, does nothing.
DB.drop_table?(:a) # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- if it already exists
# File lib/sequel/database/schema_methods.rb, line 299 299: def drop_table?(*names) 300: options = names.last.is_a?(Hash) ? names.pop : {} 301: if supports_drop_table_if_exists? 302: options = options.merge(:if_exists=>true) 303: names.each do |name| 304: drop_table(name, options) 305: end 306: else 307: names.each do |name| 308: drop_table(name, options) if table_exists?(name) 309: end 310: end 311: end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, :cascade=>true)
Options:
:cascade : | Also drop objects depending on this view. |
PostgreSQL specific options:
:if_exists : | Do not raise an error if the view does not exist. |
:materialized : | Drop a materialized view. |
# File lib/sequel/database/schema_methods.rb, line 325 325: def drop_view(*names) 326: options = names.last.is_a?(Hash) ? names.pop : {} 327: names.each do |n| 328: execute_ddl(drop_view_sql(n, options)) 329: remove_cached_schema(n) 330: end 331: nil 332: end
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 351 351: def rename_column(table, *args) 352: alter_table(table) {rename_column(*args)} 353: end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb, line 339 339: def rename_table(name, new_name) 340: execute_ddl(rename_table_sql(name, new_name)) 341: remove_cached_schema(name) 342: nil 343: end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 360 360: def set_column_default(table, *args) 361: alter_table(table) {set_column_default(*args)} 362: end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table.
# File lib/sequel/database/schema_methods.rb, line 369 369: def set_column_type(table, *args) 370: alter_table(table) {set_column_type(*args)} 371: end
STRING_DEFAULT_RE | = | /\A'(.*)'\z/ |
CURRENT_TIMESTAMP_RE | = | /now|CURRENT|getdate|\ADate\(\)\z/io |
COLUMN_SCHEMA_DATETIME_TYPES | = | [:date, :datetime] |
COLUMN_SCHEMA_STRING_TYPES | = | [:string, :blob, :date, :datetime, :time, :enum, :set, :interval] |
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].filter(:id=>1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb, line 35 35: def call(ps_name, hash={}, &block) 36: prepared_statement(ps_name).call(hash, &block) 37: end
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb, line 42 42: def execute_ddl(sql, opts=OPTS, &block) 43: execute_dui(sql, opts, &block) 44: end
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb, line 56 56: def execute_insert(sql, opts=OPTS, &block) 57: execute_dui(sql, opts, &block) 58: end
Runs the supplied SQL statement string on the database server. Returns nil. Options:
:server : | The server to run the SQL on. |
DB.run("SET some_server_variable = 42")
# File lib/sequel/database/query.rb, line 74 74: def run(sql, opts=OPTS) 75: sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) 76: execute_ddl(sql, opts) 77: nil 78: end
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
:reload : | Ignore any cached results, and get fresh information from the database. |
:schema : | An explicit schema to use. It may also be implicitly provided via the table name. |
If schema parsing is supported by the database, the column information should hash at least contain the following entries:
:allow_null : | Whether NULL is an allowed value for the column. |
:db_type : | The database type for the column, as a database specific string. |
:default : | The database default for the column, as a database specific string. |
:primary_key : | Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key. |
:ruby_default : | The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value. |
:type : | A symbol specifying the type, such as :integer or :string. |
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb, line 120 120: def schema(table, opts=OPTS) 121: raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? 122: 123: opts = opts.dup 124: tab = if table.is_a?(Dataset) 125: o = table.opts 126: from = o[:from] 127: raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) 128: table.first_source_table 129: else 130: table 131: end 132: 133: qualifiers = split_qualifiers(tab) 134: table_name = qualifiers.pop 135: sch = qualifiers.pop 136: information_schema_schema = case qualifiers.length 137: when 1 138: Sequel.identifier(*qualifiers) 139: when 2 140: Sequel.qualify(*qualifiers) 141: end 142: 143: if table.is_a?(Dataset) 144: quoted_name = table.literal(tab) 145: opts[:dataset] = table 146: else 147: quoted_name = schema_utility_dataset.literal(table) 148: end 149: 150: opts[:schema] = sch if sch && !opts.include?(:schema) 151: opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) 152: 153: Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] 154: if v = Sequel.synchronize{@schemas[quoted_name]} 155: return v 156: end 157: 158: cols = schema_parse_table(table_name, opts) 159: raise(Error, 'schema parsing returned no columns, table probably doesn\'t exist') if cols.nil? || cols.empty? 160: cols.each{|_,c| c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type])} 161: Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema 162: cols 163: end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don‘t have permission to SELECT from the table.
# File lib/sequel/database/query.rb, line 173 173: def table_exists?(name) 174: sch, table_name = schema_and_table(name) 175: name = SQL::QualifiedIdentifier.new(sch, table_name) if sch 176: _table_exists?(from(name)) 177: true 178: rescue DatabaseError 179: false 180: end
These methods all return instances of this database‘s dataset class.
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
# File lib/sequel/database/dataset.rb, line 19 19: def [](*args) 20: args.first.is_a?(String) ? fetch(*args) : from(*args) 21: end
Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch can also perform parameterized queries for protection against SQL injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
# File lib/sequel/database/dataset.rb, line 44 44: def fetch(sql, *args, &block) 45: ds = @default_dataset.with_sql(sql, *args) 46: ds.each(&block) if block 47: ds 48: end
Returns a new dataset with the from method invoked. If a block is given, it is used as a filter on the dataset.
DB.from(:items) # SELECT * FROM items DB.from(:items){id > 2} # SELECT * FROM items WHERE (id > 2)
# File lib/sequel/database/dataset.rb, line 55 55: def from(*args, &block) 56: ds = @default_dataset.from(*args) 57: block ? ds.filter(&block) : ds 58: end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version{}} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb, line 65 65: def select(*args, &block) 66: @default_dataset.select(*args, &block) 67: end
These methods all return booleans, with most describing whether or not the database supprots a given feature.