The sql_expr extension adds the sql_expr method to every object, which returns an object that works nicely with Sequel‘s DSL. This is best shown by example:
1.sql_expr < :a # 1 < a false.sql_expr & :a # FALSE AND a true.sql_expr | :a # TRUE OR a ~nil.sql_expr # NOT NULL "a".sql_expr + "b" # 'a' || 'b'
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. | |
SELECT_SERIAL_SEQUENCE | = | proc do |schema, table| <<-end_sql SELECT '"' || name.nspname || '".' || seq.relname || '' FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons WHERE seq.oid = dep.objid AND seq.relnamespace = name.oid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND cons.contype = 'p' #{"AND name.nspname = '#{schema}'" if schema} AND seq.relname = '#{table}' end_sql | ||
LOCAL_DATETIME_OFFSET_SECS | = | Time.now.utc_offset | The offset of the current time zone from UTC, in seconds. | |
LOCAL_DATETIME_OFFSET | = | respond_to?(:Rational, true) ? Rational(LOCAL_DATETIME_OFFSET_SECS, 60*60*24) : LOCAL_DATETIME_OFFSET_SECS/60/60/24.0 | The offset of the current time zone from UTC, as a fraction of a day. | |
MAJOR | = | 3 | ||
MINOR | = | 12 | ||
TINY | = | 1 | ||
VERSION | = | [MAJOR, MINOR, TINY].join('.') | ||
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. |
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 setting this to false. |
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, set this to DateTime. |
virtual_row_instance_eval | [RW] |
Lets you create a Model subclass with its dataset already set. source can be an existing dataset or a symbol (in which case it will create a dataset using the default database with the given symbol as the table name).
The purpose of this method is to set the dataset 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, and allows it to work correctly in a system that uses code reloading.
Example:
class Comment < Sequel::Model(:something) table_name # => :something end
# File lib/sequel/model.rb, line 19 19: def self.Model(source) 20: Model::ANONYMOUS_MODEL_CLASSES[source] ||= if source.is_a?(Database) 21: c = Class.new(Model) 22: c.db = source 23: c 24: else 25: Class.new(Model).set_dataset(source) 26: end 27: end
Returns true if the passed object could be a specifier of conditions, false otherwise. Currently, Sequel considers hashes and arrays of all two pairs as condition specifiers.
# File lib/sequel/core.rb, line 97 97: def self.condition_specifier?(obj) 98: case obj 99: when Hash 100: true 101: when Array 102: !obj.empty? && obj.all?{|i| (Array === i) && (i.length == 2)} 103: else 104: false 105: end 106: 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 126 126: def self.connect(*args, &block) 127: Database.connect(*args, &block) 128: 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 133 133: def self.convert_exception_class(exception, klass) 134: return exception if exception.is_a?(klass) 135: e = klass.new("#{exception.class}: #{exception.message}") 136: e.wrapped_exception = exception 137: e.set_backtrace(exception.backtrace) 138: e 139: end
Load all Sequel extensions given. Only loads extensions included in this release of Sequel, doesn‘t load external extensions.
Sequel.extension(:schema_dumper) Sequel.extension(:pagination, :query)
# File lib/sequel/core.rb, line 146 146: def self.extension(*extensions) 147: extensions.each{|e| tsk_require "sequel/extensions/#{e}"} 148: 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 161 161: def self.identifier_input_method=(value) 162: Database.identifier_input_method = value 163: 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 177 177: def self.identifier_output_method=(value) 178: Database.identifier_output_method = value 179: 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
Allowing loading the necessary JDBC support via a gem, which works for PostgreSQL, MySQL, and SQLite.
# File lib/sequel/adapters/jdbc.rb, line 81 81: def self.load_gem(name) 82: begin 83: Sequel.tsk_require "jdbc/#{name}" 84: rescue LoadError 85: # jdbc gem not used, hopefully the user has the .jar in their CLASSPATH 86: end 87: 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 124 124: def self.migration(&block) 125: MigrationDSL.create(&block) 126: 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.
# File lib/sequel/core.rb, line 191 191: def self.require(files, subdir=nil) 192: Array(files).each{|f| super("#{File.dirname(__FILE__)}/#{"#{subdir}/" if subdir}#{f}")} 193: end
Set whether to set the single threaded mode for all databases by default. By default, Sequel uses a threadsafe connection pool, which isn‘t as fast as the single threaded connection pool. If your program will only have one thread, and speed is a priority, you may want to set this to true:
Sequel.single_threaded = true
# File lib/sequel/core.rb, line 201 201: def self.single_threaded=(value) 202: Database.single_threaded = value 203: end
Converts the given string into a Date object.
# File lib/sequel/core.rb, line 206 206: def self.string_to_date(s) 207: begin 208: Date.parse(s, Sequel.convert_two_digit_years) 209: rescue => e 210: raise convert_exception_class(e, InvalidValue) 211: end 212: end
Converts the given string into a Time or DateTime object, depending on the value of Sequel.datetime_class.
# File lib/sequel/core.rb, line 216 216: def self.string_to_datetime(s) 217: begin 218: if datetime_class == DateTime 219: DateTime.parse(s, convert_two_digit_years) 220: else 221: datetime_class.parse(s) 222: end 223: rescue => e 224: raise convert_exception_class(e, InvalidValue) 225: end 226: end
Converts the given string into a Time object.
# File lib/sequel/core.rb, line 229 229: def self.string_to_time(s) 230: begin 231: Time.parse(s) 232: rescue => e 233: raise convert_exception_class(e, InvalidValue) 234: end 235: end
Same as Sequel.require, but wrapped in a mutex in order to be thread safe.
# File lib/sequel/core.rb, line 238 238: def self.ts_require(*args) 239: check_requiring_thread{require(*args)} 240: end
Same as Kernel.require, but wrapped in a mutex in order to be thread safe.
# File lib/sequel/core.rb, line 243 243: def self.tsk_require(*args) 244: check_requiring_thread{k_require(*args)} 245: end
If the supplied block takes a single argument, yield a new SQL::VirtualRow instance to the block argument. Otherwise, evaluate the block in the context of a new SQL::VirtualRow instance.
# File lib/sequel/core.rb, line 251 251: def self.virtual_row(&block) 252: vr = SQL::VirtualRow.new 253: case block.arity 254: when -1, 0 255: vr.instance_eval(&block) 256: else 257: block.call(vr) 258: end 259: end