Top level module for Sequel
There are some class methods that are added via metaprogramming, one for each supported adapter. For example:
DB = Sequel.sqlite # Memory database DB = Sequel.sqlite('blog.db') DB = Sequel.postgres('database_name', :user=>'user', :password=>'password', :host=>'host', :port=>5432, :max_connections=>10)
If a block is given to these methods, it is passed the opened Database object, which is closed (disconnected) when the block exits, just like a block passed to connect. For example:
Sequel.sqlite('blog.db'){|db| puts db[:users].count}
Sequel converts the column type tinyint to a boolean by default, you can override the conversion to use tinyint as an integer:
Sequel.convert_tinyint_to_bool = false
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:
Sequel.convert_two_digit_years = false
Sequel can use either Time or DateTime for times returned from the database. It defaults to Time. To change it to DateTime, use:
Sequel.datetime_class = DateTime
You can set the SEQUEL_NO_CORE_EXTENSIONS constant or environment variable to have Sequel not extend the core classes.
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 | ||
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. | |
MAJOR | = | 3 | ||
MINOR | = | 0 | ||
TINY | = | 0 | ||
VERSION | = | [MAJOR, MINOR, TINY].join('.') |
convert_tinyint_to_bool | [RW] | |
convert_two_digit_years | [RW] | |
datetime_class | [RW] | |
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] ||= Class.new(Model).set_dataset(source) 21: 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 52 52: def self.condition_specifier?(obj) 53: case obj 54: when Hash 55: true 56: when Array 57: !obj.empty? && obj.all?{|i| (Array === i) && (i.length == 2)} 58: else 59: false 60: end 61: 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}
# File lib/sequel/core.rb, line 78 78: def self.connect(*args, &block) 79: Database.connect(*args, &block) 80: 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 93 93: def self.identifier_input_method=(value) 94: Database.identifier_input_method = value 95: 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 109 109: def self.identifier_output_method=(value) 110: Database.identifier_output_method = value 111: 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 75 75: def self.load_gem(name) 76: begin 77: require "jdbc/#{name}" 78: rescue LoadError 79: # jdbc gem not used, hopefully the user has the .jar in their CLASSPATH 80: end 81: 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 123 123: def self.require(files, subdir=nil) 124: Array(files).each{|f| super("#{File.dirname(__FILE__)}/#{"#{subdir}/" if subdir}#{f}")} 125: 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 133 133: def self.single_threaded=(value) 134: Database.single_threaded = value 135: end
Converts the given string into a Date object.
# File lib/sequel/core.rb, line 138 138: def self.string_to_date(s) 139: begin 140: Date.parse(s, Sequel.convert_two_digit_years) 141: rescue => e 142: raise InvalidValue, "Invalid Date value '#{self}' (#{e.message})" 143: end 144: 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 148 148: def self.string_to_datetime(s) 149: begin 150: if datetime_class == DateTime 151: DateTime.parse(s, convert_two_digit_years) 152: else 153: datetime_class.parse(s) 154: end 155: rescue => e 156: raise InvalidValue, "Invalid #{datetime_class} value '#{self}' (#{e.message})" 157: end 158: end