Module: Sequel

Extended by:
EvalInspect, Metaprogramming, NamedTimezones, SQL::Builders, SQL::OperatorBuilders, ThreadLocalTimezones, Timezones
Includes:
SQL::Constants
Defined in:
lib/sequel/core.rb,
lib/sequel/sql.rb,
lib/sequel/model.rb,
lib/sequel/version.rb,
lib/sequel/dataset.rb,
lib/sequel/database.rb,
lib/sequel/timezones.rb,
lib/sequel/model/base.rb,
lib/sequel/exceptions.rb,
lib/sequel/deprecated.rb,
lib/sequel/dataset/sql.rb,
lib/sequel/adapters/do.rb,
lib/sequel/adapters/ado.rb,
lib/sequel/model/errors.rb,
lib/sequel/plugins/list.rb,
lib/sequel/adapters/dbi.rb,
lib/sequel/adapters/db2.rb,
lib/sequel/plugins/tree.rb,
lib/sequel/dataset/misc.rb,
lib/sequel/dataset/graph.rb,
lib/sequel/adapters/odbc.rb,
lib/sequel/dataset/query.rb,
lib/sequel/adapters/mock.rb,
lib/sequel/adapters/jdbc.rb,
lib/sequel/plugins/touch.rb,
lib/sequel/database/misc.rb,
lib/sequel/model/plugins.rb,
lib/sequel/plugins/dirty.rb,
lib/sequel/database/query.rb,
lib/sequel/plugins/pg_row.rb,
lib/sequel/adapters/swift.rb,
lib/sequel/plugins/schema.rb,
lib/sequel/adapters/mysql.rb,
lib/sequel/adapters/ibmdb.rb,
lib/sequel/adapters/mysql2.rb,
lib/sequel/ast_transformer.rb,
lib/sequel/adapters/oracle.rb,
lib/sequel/adapters/sqlite.rb,
lib/sequel/adapters/cubrid.rb,
lib/sequel/plugins/caching.rb,
lib/sequel/dataset/actions.rb,
lib/sequel/plugins/scissors.rb,
lib/sequel/dataset/mutation.rb,
lib/sequel/dataset/features.rb,
lib/sequel/plugins/sharding.rb,
lib/sequel/adapters/jdbc/h2.rb,
lib/sequel/database/dataset.rb,
lib/sequel/extensions/query.rb,
lib/sequel/model/exceptions.rb,
lib/sequel/database/logging.rb,
lib/sequel/adapters/tinytds.rb,
lib/sequel/adapters/informix.rb,
lib/sequel/adapters/firebird.rb,
lib/sequel/database/features.rb,
lib/sequel/extensions/to_dot.rb,
lib/sequel/adapters/do/mysql.rb,
lib/sequel/adapters/openbase.rb,
lib/sequel/model/inflections.rb,
lib/sequel/extensions/pg_row.rb,
lib/sequel/adapters/jdbc/db2.rb,
lib/sequel/adapters/postgres.rb,
lib/sequel/plugins/rcte_tree.rb,
lib/sequel/plugins/subclasses.rb,
lib/sequel/plugins/eager_each.rb,
lib/sequel/model/associations.rb,
lib/sequel/adapters/jdbc/jtds.rb,
lib/sequel/adapters/do/sqlite.rb,
lib/sequel/plugins/timestamps.rb,
lib/sequel/adapters/ado/mssql.rb,
lib/sequel/extensions/pg_inet.rb,
lib/sequel/extensions/pg_json.rb,
lib/sequel/adapters/jdbc/as400.rb,
lib/sequel/extensions/meta_def.rb,
lib/sequel/adapters/jdbc/derby.rb,
lib/sequel/extensions/pg_array.rb,
lib/sequel/database/connecting.rb,
lib/sequel/extensions/pg_range.rb,
lib/sequel/adapters/ado/access.rb,
lib/sequel/adapters/odbc/mssql.rb,
lib/sequel/adapters/jdbc/mysql.rb,
lib/sequel/adapters/amalgalite.rb,
lib/sequel/adapters/jdbc/mssql.rb,
lib/sequel/plugins/composition.rb,
lib/sequel/adapters/shared/db2.rb,
lib/sequel/plugins/active_model.rb,
lib/sequel/plugins/static_cache.rb,
lib/sequel/adapters/jdbc/cubrid.rb,
lib/sequel/plugins/table_select.rb,
lib/sequel/adapters/do/postgres.rb,
lib/sequel/extensions/pg_hstore.rb,
lib/sequel/model/dataset_module.rb,
lib/sequel/extensions/migration.rb,
lib/sequel/adapters/swift/mysql.rb,
lib/sequel/adapters/sqlanywhere.rb,
lib/sequel/adapters/jdbc/oracle.rb,
lib/sequel/adapters/jdbc/sqlite.rb,
lib/sequel/adapters/jdbc/hsqldb.rb,
lib/sequel/extensions/error_sql.rb,
lib/sequel/extensions/graph_each.rb,
lib/sequel/extensions/from_block.rb,
lib/sequel/adapters/swift/sqlite.rb,
lib/sequel/extensions/pagination.rb,
lib/sequel/database/transactions.rb,
lib/sequel/extensions/pg_row_ops.rb,
lib/sequel/adapters/shared/mssql.rb,
lib/sequel/plugins/serialization.rb,
lib/sequel/adapters/shared/mysql.rb,
lib/sequel/adapters/shared/sqlite.rb,
lib/sequel/adapters/jdbc/firebird.rb,
lib/sequel/adapters/shared/cubrid.rb,
lib/sequel/adapters/jdbc/informix.rb,
lib/sequel/plugins/xml_serializer.rb,
lib/sequel/plugins/force_encoding.rb,
lib/sequel/adapters/shared/access.rb,
lib/sequel/adapters/shared/oracle.rb,
lib/sequel/extensions/pg_interval.rb,
lib/sequel/plugins/error_splitter.rb,
lib/sequel/plugins/instance_hooks.rb,
lib/sequel/adapters/utils/replace.rb,
lib/sequel/extensions/pg_json_ops.rb,
lib/sequel/adapters/jdbc/progress.rb,
lib/sequel/adapters/jdbc/sqlserver.rb,
lib/sequel/extensions/pg_range_ops.rb,
lib/sequel/extensions/pretty_table.rb,
lib/sequel/extensions/eval_inspect.rb,
lib/sequel/extensions/null_dataset.rb,
lib/sequel/plugins/string_stripper.rb,
lib/sequel/plugins/association_pks.rb,
lib/sequel/database/schema_methods.rb,
lib/sequel/adapters/utils/pg_types.rb,
lib/sequel/plugins/json_serializer.rb,
lib/sequel/adapters/swift/postgres.rb,
lib/sequel/plugins/boolean_readers.rb,
lib/sequel/extensions/pg_array_ops.rb,
lib/sequel/extensions/hash_aliases.rb,
lib/sequel/extensions/server_block.rb,
lib/sequel/plugins/defaults_setter.rb,
lib/sequel/plugins/lazy_attributes.rb,
lib/sequel/plugins/update_or_create.rb,
lib/sequel/adapters/shared/postgres.rb,
lib/sequel/adapters/shared/informix.rb,
lib/sequel/extensions/filter_having.rb,
lib/sequel/adapters/shared/progress.rb,
lib/sequel/extensions/set_overrides.rb,
lib/sequel/adapters/shared/firebird.rb,
lib/sequel/extensions/_pretty_table.rb,
lib/sequel/extensions/pg_hstore_ops.rb,
lib/sequel/plugins/typecast_on_load.rb,
lib/sequel/plugins/after_initialize.rb,
lib/sequel/plugins/instance_filters.rb,
lib/sequel/plugins/unlimited_update.rb,
lib/sequel/extensions/schema_dumper.rb,
lib/sequel/extensions/select_remove.rb,
lib/sequel/plugins/auto_validations.rb,
lib/sequel/adapters/jdbc/postgresql.rb,
lib/sequel/plugins/input_transformer.rb,
lib/sequel/adapters/jdbc/sqlanywhere.rb,
lib/sequel/plugins/nested_attributes.rb,
lib/sequel/extensions/schema_caching.rb,
lib/sequel/extensions/query_literals.rb,
lib/sequel/plugins/many_through_many.rb,
lib/sequel/model/default_inflections.rb,
lib/sequel/database/dataset_defaults.rb,
lib/sequel/database/schema_generator.rb,
lib/sequel/extensions/pg_loose_count.rb,
lib/sequel/plugins/blacklist_security.rb,
lib/sequel/plugins/validation_helpers.rb,
lib/sequel/plugins/update_primary_key.rb,
lib/sequel/extensions/named_timezones.rb,
lib/sequel/plugins/optimistic_locking.rb,
lib/sequel/plugins/hook_class_methods.rb,
lib/sequel/extensions/date_arithmetic.rb,
lib/sequel/adapters/jdbc/transactions.rb,
lib/sequel/extensions/split_array_nil.rb,
lib/sequel/plugins/association_proxies.rb,
lib/sequel/plugins/skip_create_refresh.rb,
lib/sequel/plugins/pg_typecast_on_load.rb,
lib/sequel/dataset/prepared_statements.rb,
lib/sequel/adapters/shared/sqlanywhere.rb,
lib/sequel/plugins/prepared_statements.rb,
lib/sequel/extensions/arbitrary_servers.rb,
lib/sequel/plugins/dataset_associations.rb,
lib/sequel/plugins/many_to_one_pk_lookup.rb,
lib/sequel/plugins/pg_array_associations.rb,
lib/sequel/extensions/looser_typecasting.rb,
lib/sequel/plugins/tactical_eager_loading.rb,
lib/sequel/plugins/constraint_validations.rb,
lib/sequel/extensions/connection_validator.rb,
lib/sequel/plugins/class_table_inheritance.rb,
lib/sequel/plugins/single_table_inheritance.rb,
lib/sequel/adapters/utils/stored_procedures.rb,
lib/sequel/plugins/prepared_statements_safe.rb,
lib/sequel/plugins/association_dependencies.rb,
lib/sequel/plugins/validation_class_methods.rb,
lib/sequel/plugins/mssql_optimistic_locking.rb,
lib/sequel/extensions/columns_introspection.rb,
lib/sequel/extensions/thread_local_timezones.rb,
lib/sequel/plugins/association_autoreloading.rb,
lib/sequel/extensions/constraint_validations.rb,
lib/sequel/extensions/pg_static_cache_updater.rb,
lib/sequel/extensions/sequel_3_dataset_methods.rb,
lib/sequel/plugins/prepared_statements_with_pk.rb,
lib/sequel/extensions/empty_array_ignore_nulls.rb,
lib/sequel/plugins/prepared_statements_associations.rb,
lib/sequel/adapters/shared/mysql_prepared_statements.rb,
lib/sequel/extensions/mssql_emulate_lateral_with_apply.rb,
lib/sequel/plugins/serialization_modification_detection.rb,
lib/sequel/adapters/utils/emulate_offset_with_row_number.rb,
lib/sequel/adapters/utils/emulate_offset_with_reverse_and_count.rb

Overview

The mssql_emulate_lateral_with_apply extension converts queries that use LATERAL into queries that use CROSS/OUTER APPLY, allowing code that works on databases that support LATERAL via Dataset#lateral to run on Microsoft SQL Server and Sybase SQLAnywhere.

This is available as a separate extension instead of integrated into the Microsoft SQL Server and Sybase SQLAnywhere support because few people need it and there is a performance hit to code that doesn't use it.

It is possible there are cases where this emulation does not work. Users should probably verify that correct results are returned when using this extension.

You can load this extension into specific datasets:

ds = DB[:table]
ds = ds.extension(:mssql_emulate_lateral_with_apply)

Or you can load it into all of a database's datasets:

DB.extension(:mssql_emulate_lateral_with_apply)

Defined Under Namespace

Modules: ADO, Access, Amalgalite, ArbitraryServers, ColumnsIntrospection, ConnectionValidator, ConstraintValidations, CoreRefinements, Cubrid, DB2, DBI, DataObjects, DatabaseQuery, DatasetPagination, DatasetPrinter, DatasetQuery, Deprecation, EmptyArrayIgnoreNulls, EmulateOffsetWithReverseAndCount, EmulateOffsetWithRowNumber, ErrorSQL, EvalInspect, FilterHaving, Firebird, GraphEach, HashAliases, IBMDB, Inflections, Informix, JDBC, LooserTypecasting, MSSQL, Metaprogramming, Mock, MySQL, Mysql2, NamedTimezones, ODBC, OpenBase, Oracle, Plugins, Postgres, PrettyTable, Progress, QueryLiterals, SQL, SQLite, Schema, SchemaCaching, SchemaDumper, SelectRemove, Sequel3DatasetMethods, ServerBlock, SetOverrides, SqlAnywhere, Swift, ThreadLocalTimezones, ThreadedServerBlock, Timezones, TinyTDS, UnthreadedServerBlock Classes: ASTTransformer, AdapterNotFound, BasicObject, CheckConstraintViolation, ConnectionPool, ConstraintViolation, Database, DatabaseConnectionError, DatabaseDisconnectError, DatabaseError, Dataset, Error, ForeignKeyConstraintViolation, HookFailed, IntegerMigrator, InvalidOperation, InvalidValue, LiteralString, Migration, MigrationAlterTableReverser, MigrationDSL, MigrationReverser, Migrator, Model, NoExistingObject, NoMatchingRow, NotNullConstraintViolation, PoolTimeout, Qualifier, Rollback, SQLTime, SerializationFailure, ShardedSingleConnectionPool, ShardedThreadedConnectionPool, SimpleMigration, SingleConnectionPool, ThreadedConnectionPool, TimestampMigrator, ToDot, UnbindDuplicate, Unbinder, UndefinedAssociation, UniqueConstraintViolation, ValidationFailed

Constant Summary

OPTS =

Frozen hash used as the default options hash for most options.

{}.freeze
COLUMN_REF_RE1 =
/\A((?:(?!__).)+)__((?:(?!___).)+)___(.+)\z/.freeze
COLUMN_REF_RE2 =
/\A((?:(?!___).)+)___(.+)\z/.freeze
COLUMN_REF_RE3 =
/\A((?:(?!__).)+)__(.+)\z/.freeze
MAJOR =

The major version of Sequel. Only bumped for major changes.

4
MINOR =

The minor version of Sequel. Bumped for every non-patch level release, generally around once a month.

8
TINY =

The tiny version of Sequel. Usually 0, only bumped for bugfix releases that fix regressions from previous versions.

0
VERSION =

The version of Sequel you are using, as a string (e.g. “2.11.0”)

[MAJOR, MINOR, TINY].join('.')
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.

[]
BeforeHookFailed =

Alias for HookFailed, kept for backwards compatibility

HookFailed
DEFAULT_INFLECTIONS_PROC =

Proc that is instance evaled to create the default inflections for both the model inflector and the inflector extension.

proc do
  plural(/$/, 's')
  plural(/s$/i, 's')
  plural(/(alias|(?:stat|octop|vir|b)us)$/i, '\1es')
  plural(/(buffal|tomat)o$/i, '\1oes')
  plural(/([ti])um$/i, '\1a')
  plural(/sis$/i, 'ses')
  plural(/(?:([^f])fe|([lr])f)$/i, '\1\2ves')
  plural(/(hive)$/i, '\1s')
  plural(/([^aeiouy]|qu)y$/i, '\1ies')
  plural(/(x|ch|ss|sh)$/i, '\1es')
  plural(/(matr|vert|ind)ix|ex$/i, '\1ices')
  plural(/([m|l])ouse$/i, '\1ice')

  singular(/s$/i, '')
  singular(/([ti])a$/i, '\1um')
  singular(/(analy|ba|cri|diagno|parenthe|progno|synop|the)ses$/i, '\1sis')
  singular(/([^f])ves$/i, '\1fe')
  singular(/([h|t]ive)s$/i, '\1')
  singular(/([lr])ves$/i, '\1f')
  singular(/([^aeiouy]|qu)ies$/i, '\1y')
  singular(/(m)ovies$/i, '\1ovie')
  singular(/(x|ch|ss|sh)es$/i, '\1')
  singular(/([m|l])ice$/i, '\1ouse')
  singular(/buses$/i, 'bus')
  singular(/oes$/i, 'o')
  singular(/shoes$/i, 'shoe')
  singular(/(alias|(?:stat|octop|vir|b)us)es$/i, '\1')
  singular(/(vert|ind)ices$/i, '\1ex')
  singular(/matrices$/i, 'matrix')

  irregular('person', 'people')
  irregular('man', 'men')
  irregular('child', 'children')
  irregular('sex', 'sexes')
  irregular('move', 'moves')
  irregular('quiz', 'quizzes')
  irregular('testis', 'testes')

  uncountable(%w(equipment information rice money species series fish sheep news))
end

Constants included from SQL::Constants

SQL::Constants::CURRENT_DATE, SQL::Constants::CURRENT_TIME, SQL::Constants::CURRENT_TIMESTAMP, SQL::Constants::NOTNULL, SQL::Constants::NULL, SQL::Constants::SQLFALSE, SQL::Constants::SQLTRUE

Class Attribute Summary (collapse)

Attributes included from NamedTimezones

#tzinfo_disambiguator

Attributes included from Timezones

#application_timezone, #database_timezone, #typecast_timezone

Class Method Summary (collapse)

Methods included from EvalInspect

eval_inspect

Methods included from Metaprogramming

meta_def

Methods included from Timezones

application_to_database_timestamp, convert_output_timestamp, convert_timestamp, database_to_application_timestamp, default_timezone=, typecast_to_application_timestamp

Methods included from SQL::OperatorBuilders

~

Methods included from SQL::Builders

as, asc, blob, case, cast, cast_numeric, cast_string, char_length, date_add, date_sub, deep_qualify, delay, desc, expr, extract, function, hstore, hstore_op, identifier, ilike, join, like, lit, negate, or, pg_array, pg_array_op, pg_json, pg_json_op, pg_range, pg_range_op, pg_row, pg_row_op, qualify, subscript, trim, value_list

Class Attribute Details

+ (Object) cache_anonymous_models

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.



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# File 'lib/sequel/model.rb', line 58

def cache_anonymous_models
  @cache_anonymous_models
end

+ (Object) convert_two_digit_years

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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# File 'lib/sequel/core.rb', line 36

def convert_two_digit_years
  @convert_two_digit_years
end

+ (Object) datetime_class

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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# File 'lib/sequel/core.rb', line 50

def datetime_class
  @datetime_class
end

Class Method Details

+ (Object) adapter_method(adapter, *args, &block)

Helper method that the database adapter class methods that are added to Sequel via metaprogramming use to parse arguments.



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# File 'lib/sequel/core.rb', line 361

def self.adapter_method(adapter, *args, &block)
  options = args.last.is_a?(Hash) ? args.pop : {}
  opts = {:adapter => adapter.to_sym}
  opts[:database] = args.shift if args.first.is_a?(String)
  if args.any?
    raise ::Sequel::Error, "Wrong format of arguments, either use (), (String), (Hash), or (String, Hash)"
  end

  connect(opts.merge(options), &block)
end

+ (Boolean) condition_specifier?(obj)

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


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# File 'lib/sequel/core.rb', line 62

def self.condition_specifier?(obj)
  case obj
  when Hash
    true
  when Array
    !obj.empty? && !obj.is_a?(SQL::ValueList) && obj.all?{|i| i.is_a?(Array) && (i.length == 2)}
  else
    false
  end
end

+ (Object) connect(*args, &block)

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.



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# File 'lib/sequel/core.rb', line 94

def self.connect(*args, &block)
  Database.connect(*args, &block)
end

+ (Object) convert_exception_class(exception, klass)

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.



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# File 'lib/sequel/core.rb', line 107

def self.convert_exception_class(exception, klass)
  return exception if exception.is_a?(klass)
  e = klass.new("#{exception.class}: #{exception.message}")
  e.wrapped_exception = exception
  e.set_backtrace(exception.backtrace)
  e
end

+ (Boolean) core_extensions?

This extension loads the core extensions.



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# File 'lib/sequel/core.rb', line 100

def self.core_extensions?
  false
end

+ (Object) def_adapter_method(*adapters)

Method that adds a database adapter class method to Sequel that calls Sequel.adapter_method.

Do not call this method with untrusted input, as that can result in arbitrary code execution.



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# File 'lib/sequel/core.rb', line 377

def self.def_adapter_method(*adapters) # :nodoc:
  adapters.each do |adapter|
    instance_eval("def #{adapter}(*args, &block); adapter_method('#{adapter}', *args, &block) end", __FILE__, __LINE__)
  end
end

+ (Object) extension(*extensions)

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)


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# File 'lib/sequel/core.rb', line 125

def self.extension(*extensions)
  extensions.each{|e| Kernel.require "sequel/extensions/#{e}"}
end

+ (Object) identifier_input_method=(value)

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.



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# File 'lib/sequel/core.rb', line 140

def self.identifier_input_method=(value)
  Database.identifier_input_method = value
end

+ (Object) identifier_output_method=(value)

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.



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# File 'lib/sequel/core.rb', line 156

def self.identifier_output_method=(value)
  Database.identifier_output_method = value
end

+ (Object) inflections {|Inflections| ... }

Yield the Inflections module if a block is given, and return the Inflections module.

Yields:



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# File 'lib/sequel/model/inflections.rb', line 4

def self.inflections
  yield Inflections if block_given?
  Inflections
end

+ (Object) json_parser_error_class

The exception classed raised if there is an error parsing JSON. This can be overridden to use an alternative json implementation.



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# File 'lib/sequel/core.rb', line 162

def self.json_parser_error_class
  JSON::ParserError
end

+ (Object) migration(&block)

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.



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# File 'lib/sequel/extensions/migration.rb', line 280

def self.migration(&block)
  MigrationDSL.create(&block)
end

+ (Object) Model(source)

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


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# File 'lib/sequel/model.rb', line 37

def self.Model(source)
  if cache_anonymous_models && (klass = Sequel.synchronize{Model::ANONYMOUS_MODEL_CLASSES[source]})
    return klass
  end
  klass = if source.is_a?(Database)
    c = Class.new(Model)
    c.db = source
    c
  else
    Class.new(Model).set_dataset(source)
  end
  Sequel.synchronize{Model::ANONYMOUS_MODEL_CLASSES[source] = klass} if cache_anonymous_models
  klass
end

+ (Object) object_to_json(obj, *args)

Convert given object to json and return the result. This can be overridden to use an alternative json implementation.



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# File 'lib/sequel/core.rb', line 168

def self.object_to_json(obj, *args)
  obj.to_json(*args)
end

+ (Object) parse_json(json)

Parse the string as JSON and return the result. This can be overridden to use an alternative json implementation.



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# File 'lib/sequel/core.rb', line 174

def self.parse_json(json)
  JSON.parse(json, :create_additions=>false)
end

+ (Object) quote_identifiers=(value)

Set whether to quote identifiers for all databases by default. By default, Sequel quotes identifiers in all SQL strings, so to turn that off:

Sequel.quote_identifiers = false


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# File 'lib/sequel/core.rb', line 182

def self.quote_identifiers=(value)
  Database.quote_identifiers = value
end

+ (Object) recursive_map(array, converter)

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.



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# File 'lib/sequel/core.rb', line 189

def self.recursive_map(array, converter)
  array.map do |i|
    if i.is_a?(Array)
      recursive_map(i, converter)
    elsif i
      converter.call(i)
    end
  end
end

+ (Object) require(files, subdir = nil)

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.



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# File 'lib/sequel/core.rb', line 203

def self.require(files, subdir=nil)
  Array(files).each{|f| super("#{File.dirname(__FILE__).untaint}/#{"#{subdir}/" if subdir}#{f}")}
end

+ (Object) single_threaded=(value)

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


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# File 'lib/sequel/core.rb', line 214

def self.single_threaded=(value)
  @single_threaded = value
  Database.single_threaded = value
end

+ (Object) split_symbol(sym)

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.



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# File 'lib/sequel/core.rb', line 228

def self.split_symbol(sym)
  case s = sym.to_s
  when COLUMN_REF_RE1
    [$1, $2, $3]
  when COLUMN_REF_RE2
    [nil, $1, $2]
  when COLUMN_REF_RE3
    [$1, $2, nil]
  else
    [nil, s, nil]
  end
end

+ (Object) string_to_date(string)

Converts the given string into a Date object.

Sequel.string_to_date('2010-09-10') # Date.civil(2010, 09, 10)


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# File 'lib/sequel/core.rb', line 244

def self.string_to_date(string)
  begin
    Date.parse(string, Sequel.convert_two_digit_years)
  rescue => e
    raise convert_exception_class(e, InvalidValue)
  end
end

+ (Object) string_to_datetime(string)

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)


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# File 'lib/sequel/core.rb', line 256

def self.string_to_datetime(string)
  begin
    if datetime_class == DateTime
      DateTime.parse(string, convert_two_digit_years)
    else
      datetime_class.parse(string)
    end
  rescue => e
    raise convert_exception_class(e, InvalidValue)
  end
end

+ (Object) string_to_time(string)

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'


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# File 'lib/sequel/core.rb', line 272

def self.string_to_time(string)
  begin
    SQLTime.parse(string)
  rescue => e
    raise convert_exception_class(e, InvalidValue)
  end
end

+ (Object) synchronize

Yield directly to the block. You don't need to synchronize access on MRI because the GVL makes certain methods atomic.



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# File 'lib/sequel/core.rb', line 288

def self.synchronize(&block)
  @single_threaded ? yield : @data_mutex.synchronize(&block)
end

+ (Object) transaction(dbs, opts = OPTS, &block)

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).



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# File 'lib/sequel/core.rb', line 323

def self.transaction(dbs, opts=OPTS, &block)
  unless opts[:rollback]
    rescue_rollback = true
    opts = opts.merge(:rollback=>:reraise)
  end
  pr = dbs.reverse.inject(block){|bl, db| proc{db.transaction(opts, &bl)}}
  if rescue_rollback
    begin
      pr.call
    rescue Sequel::Rollback
      nil
    end
  else
    pr.call
  end
end

+ (Object) version

The version of Sequel you are using, as a string (e.g. “2.11.0”)



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# File 'lib/sequel/version.rb', line 15

def self.version
  VERSION
end

+ (Object) virtual_row(&block)

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)


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# File 'lib/sequel/core.rb', line 347

def self.virtual_row(&block)
  vr = VIRTUAL_ROW
  case block.arity
  when -1, 0
    vr.instance_exec(&block)
  else
    block.call(vr)
  end  
end