The pg_hstore_ops extension adds support to Sequel‘s DSL to make it easier to call PostgreSQL hstore functions and operators.
To load the extension:
Sequel.extension :pg_hstore_ops
The most common usage is taking an object that represents an SQL expression (such as a :symbol), and calling Sequel.hstore_op with it:
h = Sequel.hstore_op(:hstore_column)
If you have also loaded the pg_hstore extension, you can use Sequel.hstore as well:
h = Sequel.hstore(:hstore_column)
Also, on most Sequel expression objects, you can call the hstore method:
h = Sequel.expr(:hstore_column).hstore
If you have loaded the core_extensions extension), or you have loaded the core_refinements extension) and have activated refinements for the file, you can also use Symbol#hstore:
h = :hstore_column.hstore
This creates a Sequel::Postgres::HStoreOp object that can be used for easier querying:
h - 'a' # hstore_column - CAST('a' AS text) h['a'] # hstore_column -> 'a' h.concat(:other_hstore_column) # || h.has_key?('a') # ? h.contain_all(:array_column) # ?& h.contain_any(:array_column) # ?| h.contains(:other_hstore_column) # @> h.contained_by(:other_hstore_column) # <@ h.defined # defined(hstore_column) h.delete('a') # delete(hstore_column, 'a') h.each # each(hstore_column) h.keys # akeys(hstore_column) h.populate(:a) # populate_record(a, hstore_column) h.record_set(:a) # (a #= hstore_column) h.skeys # skeys(hstore_column) h.slice(:a) # slice(hstore_column, a) h.svals # svals(hstore_column) h.to_array # hstore_to_array(hstore_column) h.to_matrix # hstore_to_matrix(hstore_column) h.values # avals(hstore_column)
See the PostgreSQL hstore function and operator documentation for more details on what these functions and operators do.
If you are also using the pg_hstore extension, you should load it before loading this extension. Doing so will allow you to use HStore#op to get an HStoreOp, allowing you to perform hstore operations on hstore literals.
OPTS | = | {}.freeze | Frozen hash used as the default options hash for most options. | |
COLUMN_REF_RE1 | = | /\A((?:(?!__).)+)__((?:(?!___).)+)___(.+)\z/.freeze | ||
COLUMN_REF_RE2 | = | /\A((?:(?!___).)+)___(.+)\z/.freeze | ||
COLUMN_REF_RE3 | = | /\A((?:(?!__).)+)__(.+)\z/.freeze | ||
ADAPTER_MAP | = | {} | Hash of adapters that have been used. The key is the adapter scheme symbol, and the value is the Database subclass. | |
DATABASES | = | [] | Array of all databases to which Sequel has connected. If you are developing an application that can connect to an arbitrary number of databases, delete the database objects from this or they will not get garbage collected. | |
DEFAULT_INFLECTIONS_PROC | = | proc do plural(/$/, 's') | Proc that is instance evaled to create the default inflections for both the model inflector and the inflector extension. | |
BeforeHookFailed | = | HookFailed | Deprecated alias for HookFailed, kept for backwards compatibility | |
STRING_TYPES | = | [18, 19, 25, 1042, 1043] | Type OIDs for string types used by PostgreSQL. These types don‘t have conversion procs associated with them (since the data is already in the form of a string). | |
PG_NAMED_TYPES | = | {} unless defined?(PG_NAMED_TYPES) | Hash with type name strings/symbols and callable values for converting PostgreSQL types. Non-builtin types that don‘t have fixed numbers should use this to register conversion procs. | |
PG_TYPES | = | {} unless defined?(PG_TYPES) | Hash with integer keys and callable values for converting PostgreSQL types. | |
MYSQL_TYPES | = | {} | Hash with integer keys and callable values for converting MySQL types. | |
SQLITE_TYPES | = | {} | Hash with string keys and callable values for converting SQLite types. | |
MAJOR | = | 4 | The major version of Sequel. Only bumped for major changes. | |
MINOR | = | 1 | The minor version of Sequel. Bumped for every non-patch level release, generally around once a month. | |
TINY | = | 1 | The tiny version of Sequel. Usually 0, only bumped for bugfix releases that fix regressions from previous versions. | |
VERSION | = | [MAJOR, MINOR, TINY].join('.') | The version of Sequel you are using, as a string (e.g. "2.11.0") |
autoid | [W] |
Set the autogenerated primary key integer to be returned when running an
insert query. Argument types supported:
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cache_anonymous_models | [RW] | Whether to cache the anonymous models created by Sequel::Model(). This is required for reloading them correctly (avoiding the superclass mismatch). True by default for backwards compatibility. | ||||||||||||
columns | [W] |
Set the columns to set in the dataset when the dataset fetches rows.
Argument types supported:
Array of Symbols: Used for all datasets Array (otherwise): First retrieval gets the first value in the array, second gets the second value, etc.
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convert_invalid_date_time | [RW] |
Whether to convert invalid date time values by default.
Only applies to Sequel::Database instances created after this has been set. |
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convert_two_digit_years | [RW] |
Sequel converts two digit years in Dates
and DateTimes by default, so 01/02/03 is interpreted at January
2nd, 2003, and 12/13/99 is interpreted as December 13, 1999. You can
override this to treat those dates as January 2nd, 0003 and December 13,
0099, respectively, by:
Sequel.convert_two_digit_years = false |
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datetime_class | [RW] |
Sequel can use either Time or
DateTime for times returned from the database. It defaults to
Time. To change it to DateTime:
Sequel.datetime_class = DateTime For ruby versions less than 1.9.2, Time has a limited range (1901 to 2038), so if you use datetimes out of that range, you need to switch to DateTime. Also, before 1.9.2, Time can only handle local and UTC times, not other timezones. Note that Time and DateTime objects have a different API, and in cases where they implement the same methods, they often implement them differently (e.g. + using seconds on Time and days on DateTime). |
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fetch | [W] |
Set the hashes to yield by execute when
retrieving rows. Argument types supported:
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numrows | [W] |
Set the number of rows to return from update or delete. Argument types
supported:
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server_version | [RW] | Mock the server version, useful when using the shared adapters |
Lets you create a Model subclass with its dataset already set. source should be an instance of one of the following classes:
Database : | Sets the database for this model to source. Generally only useful when subclassing directly from the returned class, where the name of the subclass sets the table name (which is combined with the Database in source to create the dataset to use) |
Dataset : | Sets the dataset for this model to source. |
other : | Sets the table name for this model to source. The class will use the default database for model classes in order to create the dataset. |
The purpose of this method is to set the dataset/database automatically for a model class, if the table name doesn‘t match the implicit name. This is neater than using set_dataset inside the class, doesn‘t require a bogus query for the schema.
# Using a symbol class Comment < Sequel::Model(:something) table_name # => :something end # Using a dataset class Comment < Sequel::Model(DB1[:something]) dataset # => DB1[:something] end # Using a database class Comment < Sequel::Model(DB1) dataset # => DB1[:comments] end
# File lib/sequel/model.rb, line 37 37: def self.Model(source) 38: if cache_anonymous_models && (klass = Sequel.synchronize{Model::ANONYMOUS_MODEL_CLASSES[source]}) 39: return klass 40: end 41: klass = if source.is_a?(Database) 42: c = Class.new(Model) 43: c.db = source 44: c 45: else 46: Class.new(Model).set_dataset(source) 47: end 48: Sequel.synchronize{Model::ANONYMOUS_MODEL_CLASSES[source] = klass} if cache_anonymous_models 49: klass 50: end
Returns true if the passed object could be a specifier of conditions, false otherwise. Currently, Sequel considers hashes and arrays of two element arrays as condition specifiers.
Sequel.condition_specifier?({}) # => true Sequel.condition_specifier?([[1, 2]]) # => true Sequel.condition_specifier?([]) # => false Sequel.condition_specifier?([1]) # => false Sequel.condition_specifier?(1) # => false
# File lib/sequel/core.rb, line 62 62: def self.condition_specifier?(obj) 63: case obj 64: when Hash 65: true 66: when Array 67: !obj.empty? && !obj.is_a?(SQL::ValueList) && obj.all?{|i| i.is_a?(Array) && (i.length == 2)} 68: else 69: false 70: end 71: end
Creates a new database object based on the supplied connection string and optional arguments. The specified scheme determines the database class used, and the rest of the string specifies the connection options. For example:
DB = Sequel.connect('sqlite:/') # Memory database DB = Sequel.connect('sqlite://blog.db') # ./blog.db DB = Sequel.connect('sqlite:///blog.db') # /blog.db DB = Sequel.connect('postgres://user:password@host:port/database_name') DB = Sequel.connect('sqlite:///blog.db', :max_connections=>10)
If a block is given, it is passed the opened Database object, which is closed when the block exits. For example:
Sequel.connect('sqlite://blog.db'){|db| puts db[:users].count}
For details, see the "Connecting to a Database" guide. To set up a master/slave or sharded database connection, see the "Master/Slave Databases and Sharding" guide.
# File lib/sequel/core.rb, line 94 94: def self.connect(*args, &block) 95: Database.connect(*args, &block) 96: end
Convert the exception to the given class. The given class should be Sequel::Error or a subclass. Returns an instance of klass with the message and backtrace of exception.
# File lib/sequel/core.rb, line 107 107: def self.convert_exception_class(exception, klass) 108: return exception if exception.is_a?(klass) 109: e = klass.new("#{exception.class}: #{exception.message}") 110: e.wrapped_exception = exception 111: e.set_backtrace(exception.backtrace) 112: e 113: end
Load all Sequel extensions given. Extensions are just files that exist under sequel/extensions in the load path, and are just required. Generally, extensions modify the behavior of Database and/or Dataset, but Sequel ships with some extensions that modify other classes that exist for backwards compatibility. In some cases, requiring an extension modifies classes directly, and in others, it just loads a module that you can extend other classes with. Consult the documentation for each extension you plan on using for usage.
Sequel.extension(:schema_dumper) Sequel.extension(:pagination, :query)
# File lib/sequel/core.rb, line 125 125: def self.extension(*extensions) 126: extensions.each{|e| Kernel.require "sequel/extensions/#{e}"} 127: end
Set the method to call on identifiers going into the database. This affects the literalization of identifiers by calling this method on them before they are input. Sequel upcases identifiers in all SQL strings for most databases, so to turn that off:
Sequel.identifier_input_method = nil
to downcase instead:
Sequel.identifier_input_method = :downcase
Other String instance methods work as well.
# File lib/sequel/core.rb, line 140 140: def self.identifier_input_method=(value) 141: Database.identifier_input_method = value 142: end
Set the method to call on identifiers coming out of the database. This affects the literalization of identifiers by calling this method on them when they are retrieved from the database. Sequel downcases identifiers retrieved for most databases, so to turn that off:
Sequel.identifier_output_method = nil
to upcase instead:
Sequel.identifier_output_method = :upcase
Other String instance methods work as well.
# File lib/sequel/core.rb, line 156 156: def self.identifier_output_method=(value) 157: Database.identifier_output_method = value 158: end
Yield the Inflections module if a block is given, and return the Inflections module.
# File lib/sequel/model/inflections.rb, line 4 4: def self.inflections 5: yield Inflections if block_given? 6: Inflections 7: end
The exception classed raised if there is an error parsing JSON. This can be overridden to use an alternative json implementation.
# File lib/sequel/core.rb, line 162 162: def self.json_parser_error_class 163: JSON::ParserError 164: end
Allowing loading the necessary JDBC support via a gem, which works for PostgreSQL, MySQL, and SQLite.
# File lib/sequel/adapters/jdbc.rb, line 151 151: def self.load_gem(name) 152: begin 153: require "jdbc/#{name.to_s.downcase}" 154: rescue LoadError 155: # jdbc gem not used, hopefully the user has the .jar in their CLASSPATH 156: else 157: if defined?(::Jdbc) && ( ::Jdbc.const_defined?(name) rescue nil ) 158: jdbc_module = ::Jdbc.const_get(name) # e.g. Jdbc::SQLite3 159: jdbc_module.load_driver if jdbc_module.respond_to?(:load_driver) 160: end 161: end 162: end
The preferred method for writing Sequel migrations, using a DSL:
Sequel.migration do up do create_table(:artists) do primary_key :id String :name end end down do drop_table(:artists) end end
Designed to be used with the Migrator class, part of the migration extension.
# File lib/sequel/extensions/migration.rb, line 280 280: def self.migration(&block) 281: MigrationDSL.create(&block) 282: end
Convert given object to json and return the result. This can be overridden to use an alternative json implementation.
# File lib/sequel/core.rb, line 168 168: def self.object_to_json(obj, *args) 169: obj.to_json(*args) 170: end
Parse the string as JSON and return the result. This can be overridden to use an alternative json implementation.
# File lib/sequel/core.rb, line 174 174: def self.parse_json(json) 175: JSON.parse(json, :create_additions=>false) 176: end
Convert each item in the array to the correct type, handling multi-dimensional arrays. For each element in the array or subarrays, call the converter, unless the value is nil.
# File lib/sequel/core.rb, line 189 189: def self.recursive_map(array, converter) 190: array.map do |i| 191: if i.is_a?(Array) 192: recursive_map(i, converter) 193: elsif i 194: converter.call(i) 195: end 196: end 197: end
Require all given files which should be in the same or a subdirectory of this file. If a subdir is given, assume all files are in that subdir. This is used to ensure that the files loaded are from the same version of Sequel as this file.
# File lib/sequel/core.rb, line 203 203: def self.require(files, subdir=nil) 204: Array(files).each{|f| super("#{File.dirname(__FILE__).untaint}/#{"#{subdir}/" if subdir}#{f}")} 205: end
Set whether Sequel is being used in single threaded mode. By default, Sequel uses a thread-safe connection pool, which isn‘t as fast as the single threaded connection pool, and also has some additional thread safety checks. If your program will only have one thread, and speed is a priority, you should set this to true:
Sequel.single_threaded = true
# File lib/sequel/core.rb, line 214 214: def self.single_threaded=(value) 215: @single_threaded = value 216: Database.single_threaded = value 217: end
Splits the symbol into three parts. Each part will either be a string or nil.
For columns, these parts are the table, column, and alias. For tables, these parts are the schema, table, and alias.
# File lib/sequel/core.rb, line 228 228: def self.split_symbol(sym) 229: case s = sym.to_s 230: when COLUMN_REF_RE1 231: [$1, $2, $3] 232: when COLUMN_REF_RE2 233: [nil, $1, $2] 234: when COLUMN_REF_RE3 235: [$1, $2, nil] 236: else 237: [nil, s, nil] 238: end 239: end
Converts the given string into a Date object.
Sequel.string_to_date('2010-09-10') # Date.civil(2010, 09, 10)
# File lib/sequel/core.rb, line 244 244: def self.string_to_date(string) 245: begin 246: Date.parse(string, Sequel.convert_two_digit_years) 247: rescue => e 248: raise convert_exception_class(e, InvalidValue) 249: end 250: end
Converts the given string into a Time or DateTime object, depending on the value of Sequel.datetime_class.
Sequel.string_to_datetime('2010-09-10 10:20:30') # Time.local(2010, 09, 10, 10, 20, 30)
# File lib/sequel/core.rb, line 256 256: def self.string_to_datetime(string) 257: begin 258: if datetime_class == DateTime 259: DateTime.parse(string, convert_two_digit_years) 260: else 261: datetime_class.parse(string) 262: end 263: rescue => e 264: raise convert_exception_class(e, InvalidValue) 265: end 266: end
Converts the given string into a Sequel::SQLTime object.
v = Sequel.string_to_time('10:20:30') # Sequel::SQLTime.parse('10:20:30') DB.literal(v) # => '10:20:30'
# File lib/sequel/core.rb, line 272 272: def self.string_to_time(string) 273: begin 274: SQLTime.parse(string) 275: rescue => e 276: raise convert_exception_class(e, InvalidValue) 277: end 278: end
Yield directly to the block. You don‘t need to synchronize access on MRI because the GVL makes certain methods atomic.
# File lib/sequel/core.rb, line 295 295: def self.synchronize 296: yield 297: end
Unless in single threaded mode, protects access to any mutable global data structure in Sequel. Uses a non-reentrant mutex, so calling code should be careful.
# File lib/sequel/core.rb, line 288 288: def self.synchronize(&block) 289: @single_threaded ? yield : @data_mutex.synchronize(&block) 290: end
Uses a transaction on all given databases with the given options. This:
Sequel.transaction([DB1, DB2, DB3]){...}
is equivalent to:
DB1.transaction do DB2.transaction do DB3.transaction do ... end end end
except that if Sequel::Rollback is raised by the block, the transaction is rolled back on all databases instead of just the last one.
Note that this method cannot guarantee that all databases will commit or rollback. For example, if DB3 commits but attempting to commit on DB2 fails (maybe because foreign key checks are deferred), there is no way to uncommit the changes on DB3. For that kind of support, you need to have two-phase commit/prepared transactions (which Sequel supports on some databases).
# File lib/sequel/core.rb, line 323 323: def self.transaction(dbs, opts=OPTS, &block) 324: unless opts[:rollback] 325: rescue_rollback = true 326: opts = opts.merge(:rollback=>:reraise) 327: end 328: pr = dbs.reverse.inject(block){|bl, db| proc{db.transaction(opts, &bl)}} 329: if rescue_rollback 330: begin 331: pr.call 332: rescue Sequel::Rollback 333: nil 334: end 335: else 336: pr.call 337: end 338: end
If the supplied block takes a single argument, yield an SQL::VirtualRow instance to the block argument. Otherwise, evaluate the block in the context of a SQL::VirtualRow instance.
Sequel.virtual_row{a} # Sequel::SQL::Identifier.new(:a) Sequel.virtual_row{|o| o.a{}} # Sequel::SQL::Function.new(:a)
# File lib/sequel/core.rb, line 347 347: def self.virtual_row(&block) 348: vr = VIRTUAL_ROW 349: case block.arity 350: when -1, 0 351: vr.instance_exec(&block) 352: else 353: block.call(vr) 354: end 355: end
Return a related Connection option connecting to the given shard.
# File lib/sequel/adapters/mock.rb, line 135 135: def connect(server) 136: Connection.new(self, server, server_opts(server)) 137: end
Store the sql used for later retrieval with sqls, and return the appropriate value using either the autoid, fetch, or numrows methods.
# File lib/sequel/adapters/mock.rb, line 145 145: def execute(sql, opts=OPTS, &block) 146: synchronize(opts[:server]){|c| _execute(c, sql, opts, &block)} 147: end
Store the sql used, and return the value of the numrows method.
# File lib/sequel/adapters/mock.rb, line 151 151: def execute_dui(sql, opts=OPTS) 152: execute(sql, opts.merge(:meth=>:numrows)) 153: end
Store the sql used, and return the value of the autoid method.
# File lib/sequel/adapters/mock.rb, line 156 156: def execute_insert(sql, opts=OPTS) 157: execute(sql, opts.merge(:meth=>:autoid)) 158: end