File: cheat_sheet.rdoc [sequel-4.5.0 Documentation]

### Home Classes Methods

### Files

- CHANGELOG
- MIT-LICENSE
- README.rdoc
- active_record.rdoc
- advanced_associations.rdoc
- association_basics.rdoc
- bin_sequel.rdoc
- cheat_sheet.rdoc
- code_order.rdoc
- core_extensions.rdoc
- dataset_basics.rdoc
- dataset_filtering.rdoc
- extensions.rdoc
- mass_assignment.rdoc
- migration.rdoc
- model_hooks.rdoc
- model_plugins.rdoc
- object_model.rdoc
- opening_databases.rdoc
- postgresql.rdoc
- prepared_statements.rdoc
- querying.rdoc
- reflection.rdoc
- 1.0.txt
- 1.1.txt
- 1.3.txt
- 1.4.0.txt
- 1.5.0.txt
- 2.0.0.txt
- 2.1.0.txt
- 2.10.0.txt
- 2.11.0.txt
- 2.12.0.txt
- 2.2.0.txt
- 2.3.0.txt
- 2.4.0.txt
- 2.5.0.txt
- 2.6.0.txt
- 2.7.0.txt
- 2.8.0.txt
- 2.9.0.txt
- 3.0.0.txt
- 3.1.0.txt
- 3.10.0.txt
- 3.11.0.txt
- 3.12.0.txt
- 3.13.0.txt
- 3.14.0.txt
- 3.15.0.txt
- 3.16.0.txt
- 3.17.0.txt
- 3.18.0.txt
- 3.19.0.txt
- 3.2.0.txt
- 3.20.0.txt
- 3.21.0.txt
- 3.22.0.txt
- 3.23.0.txt
- 3.24.0.txt
- 3.25.0.txt
- 3.26.0.txt
- 3.27.0.txt
- 3.28.0.txt
- 3.29.0.txt
- 3.3.0.txt
- 3.30.0.txt
- 3.31.0.txt
- 3.32.0.txt
- 3.33.0.txt
- 3.34.0.txt
- 3.35.0.txt
- 3.36.0.txt
- 3.37.0.txt
- 3.38.0.txt
- 3.39.0.txt
- 3.4.0.txt
- 3.40.0.txt
- 3.41.0.txt
- 3.42.0.txt
- 3.43.0.txt
- 3.44.0.txt
- 3.45.0.txt
- 3.46.0.txt
- 3.47.0.txt
- 3.48.0.txt
- 3.5.0.txt
- 3.6.0.txt
- 3.7.0.txt
- 3.8.0.txt
- 3.9.0.txt
- 4.0.0.txt
- 4.1.0.txt
- 4.2.0.txt
- 4.3.0.txt
- 4.4.0.txt
- 4.5.0.txt
- schema_modification.rdoc
- security.rdoc
- sharding.rdoc
- sql.rdoc
- testing.rdoc
- thread_safety.rdoc
- transactions.rdoc
- validations.rdoc
- virtual_rows.rdoc

### Class Index

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- Sequel::Error
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- Sequel::FilterHaving
- Sequel::Firebird
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- Sequel::Firebird::DatabaseMethods
- Sequel::Firebird::Dataset
- Sequel::Firebird::DatasetMethods
- Sequel::ForeignKeyConstraintViolation
- Sequel::GraphEach
- Sequel::HashAliases
- Sequel::HookFailed
- Sequel::IBMDB
- Sequel::IBMDB::Connection
- Sequel::IBMDB::Connection::Error
- Sequel::IBMDB::Database
- Sequel::IBMDB::Dataset
- Sequel::IBMDB::Dataset::CallableStatementMethods
- Sequel::IBMDB::Dataset::PreparedStatementMethods
- Sequel::IBMDB::Statement
- Sequel::Inflections
- Sequel::Informix
- Sequel::Informix::Database
- Sequel::Informix::DatabaseMethods
- Sequel::Informix::Dataset
- Sequel::Informix::DatasetMethods
- Sequel::IntegerMigrator
- Sequel::InvalidOperation
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- Sequel::JDBC
- Sequel::JDBC::AS400
- Sequel::JDBC::AS400::DatabaseMethods
- Sequel::JDBC::AS400::Dataset
- Sequel::JDBC::Cubrid
- Sequel::JDBC::Cubrid::DatabaseMethods
- Sequel::JDBC::DB2
- Sequel::JDBC::DB2::DatabaseMethods
- Sequel::JDBC::DB2::Dataset
- Sequel::JDBC::Database
- Sequel::JDBC::Dataset
- Sequel::JDBC::Dataset::PreparedStatementMethods
- Sequel::JDBC::Dataset::StoredProcedureMethods
- Sequel::JDBC::Dataset::TYPE_TRANSLATOR
- Sequel::JDBC::Derby
- Sequel::JDBC::Derby::DatabaseMethods
- Sequel::JDBC::Derby::Dataset
- Sequel::JDBC::Firebird
- Sequel::JDBC::Firebird::DatabaseMethods
- Sequel::JDBC::H2
- Sequel::JDBC::H2::DatabaseMethods
- Sequel::JDBC::H2::Dataset
- Sequel::JDBC::HSQLDB
- Sequel::JDBC::HSQLDB::DatabaseMethods
- Sequel::JDBC::HSQLDB::Dataset
- Sequel::JDBC::Informix
- Sequel::JDBC::Informix::DatabaseMethods
- Sequel::JDBC::JTDS
- Sequel::JDBC::JTDS::DatabaseMethods
- Sequel::JDBC::JTDS::Dataset
- Sequel::JDBC::JavaLang
- Sequel::JDBC::JavaSQL
- Sequel::JDBC::JavaxNaming
- Sequel::JDBC::MSSQL
- Sequel::JDBC::MSSQL::DatabaseMethods
- Sequel::JDBC::MySQL
- Sequel::JDBC::MySQL::DatabaseMethods
- Sequel::JDBC::Oracle
- Sequel::JDBC::Oracle::DatabaseMethods
- Sequel::JDBC::Oracle::Dataset
- Sequel::JDBC::Postgres
- Sequel::JDBC::Postgres::DatabaseMethods
- Sequel::JDBC::Postgres::Dataset
- Sequel::JDBC::Postgres::Dataset::PGArrayConverter
- Sequel::JDBC::Progress
- Sequel::JDBC::Progress::DatabaseMethods
- Sequel::JDBC::SQLServer
- Sequel::JDBC::SQLServer::DatabaseMethods
- Sequel::JDBC::SQLServer::DatabaseMethods::MetadataDatasetMethods
- Sequel::JDBC::SQLite
- Sequel::JDBC::SQLite::DatabaseMethods
- Sequel::JDBC::SqlAnywhere
- Sequel::JDBC::SqlAnywhere::DatabaseMethods
- Sequel::JDBC::SqlAnywhere::Dataset
- Sequel::JDBC::Transactions
- Sequel::LiteralString
- Sequel::LooserTypecasting
- Sequel::MSSQL
- Sequel::MSSQL::DatabaseMethods
- Sequel::MSSQL::DatasetMethods
- Sequel::MSSQL::EmulateLateralWithApply
- Sequel::Metaprogramming
- Sequel::Migration
- Sequel::MigrationAlterTableReverser
- Sequel::MigrationDSL
- Sequel::MigrationReverser
- Sequel::Migrator
- Sequel::Migrator::Error
- Sequel::Migrator::NotCurrentError
- Sequel::Mock
- Sequel::Mock::Connection
- Sequel::Mock::Database
- Sequel::Mock::Dataset
- Sequel::Model
- Sequel::Model::Associations
- Sequel::Model::Associations::AssociationDatasetMethods
- Sequel::Model::Associations::AssociationReflection
- Sequel::Model::Associations::ClassMethods
- Sequel::Model::Associations::DatasetMethods
- Sequel::Model::Associations::EagerGraphLoader
- Sequel::Model::Associations::InstanceMethods
- Sequel::Model::Associations::ManyToManyAssociationReflection
- Sequel::Model::Associations::ManyToOneAssociationReflection
- Sequel::Model::Associations::OneToManyAssociationReflection
- Sequel::Model::Associations::OneToOneAssociationReflection
- Sequel::Model::ClassMethods
- Sequel::Model::DatasetMethods
- Sequel::Model::DatasetModule
- Sequel::Model::Errors
- Sequel::Model::InstanceMethods
- Sequel::MySQL
- Sequel::MySQL::Database
- Sequel::MySQL::DatabaseMethods
- Sequel::MySQL::Dataset
- Sequel::MySQL::DatasetMethods
- Sequel::MySQL::PreparedStatements
- Sequel::MySQL::PreparedStatements::DatabaseMethods
- Sequel::MySQL::PreparedStatements::DatasetMethods
- Sequel::MySQL::PreparedStatements::DatasetMethods::CallableStatementMethods
- Sequel::MySQL::PreparedStatements::DatasetMethods::PreparedStatementMethods
- Sequel::MySQL::PreparedStatements::DatasetMethods::StoredProcedureMethods
- Sequel::Mysql2
- Sequel::Mysql2::Database
- Sequel::Mysql2::Dataset
- Sequel::NamedTimezones
- Sequel::NamedTimezones::DatabaseMethods
- Sequel::NoExistingObject
- Sequel::NoMatchingRow
- Sequel::NotNullConstraintViolation
- Sequel::ODBC
- Sequel::ODBC::Database
- Sequel::ODBC::Dataset
- Sequel::ODBC::MSSQL
- Sequel::ODBC::MSSQL::DatabaseMethods
- Sequel::ODBC::MSSQL::Dataset
- Sequel::OpenBase
- Sequel::OpenBase::Database
- Sequel::OpenBase::Dataset
- Sequel::Oracle
- Sequel::Oracle::Database
- Sequel::Oracle::DatabaseMethods
- Sequel::Oracle::Dataset
- Sequel::Oracle::Dataset::ArgumentMapper
- Sequel::Oracle::Dataset::BindArgumentMethods
- Sequel::Oracle::Dataset::PreparedStatementMethods
- Sequel::Oracle::DatasetMethods
- Sequel::Plugins
- Sequel::Plugins::ActiveModel
- Sequel::Plugins::ActiveModel::ClassMethods
- Sequel::Plugins::ActiveModel::Errors
- Sequel::Plugins::ActiveModel::InstanceMethods
- Sequel::Plugins::AfterInitialize
- Sequel::Plugins::AfterInitialize::ClassMethods
- Sequel::Plugins::AfterInitialize::InstanceMethods
- Sequel::Plugins::AssociationAutoreloading
- Sequel::Plugins::AssociationDependencies
- Sequel::Plugins::AssociationDependencies::ClassMethods
- Sequel::Plugins::AssociationDependencies::InstanceMethods
- Sequel::Plugins::AssociationPks
- Sequel::Plugins::AssociationPks::ClassMethods
- Sequel::Plugins::AssociationPks::InstanceMethods
- Sequel::Plugins::AssociationProxies
- Sequel::Plugins::AssociationProxies::AssociationProxy
- Sequel::Plugins::AssociationProxies::ClassMethods
- Sequel::Plugins::AutoValidations
- Sequel::Plugins::AutoValidations::ClassMethods
- Sequel::Plugins::AutoValidations::InstanceMethods
- Sequel::Plugins::BlacklistSecurity
- Sequel::Plugins::BlacklistSecurity::ClassMethods
- Sequel::Plugins::BlacklistSecurity::InstanceMethods
- Sequel::Plugins::BlacklistSecurity::InstanceMethods::ExceptionList
- Sequel::Plugins::BooleanReaders
- Sequel::Plugins::BooleanReaders::ClassMethods
- Sequel::Plugins::Caching
- Sequel::Plugins::Caching::ClassMethods
- Sequel::Plugins::Caching::InstanceMethods
- Sequel::Plugins::ClassTableInheritance
- Sequel::Plugins::ClassTableInheritance::ClassMethods
- Sequel::Plugins::ClassTableInheritance::InstanceMethods
- Sequel::Plugins::Composition
- Sequel::Plugins::Composition::ClassMethods
- Sequel::Plugins::Composition::InstanceMethods
- Sequel::Plugins::ConstraintValidations
- Sequel::Plugins::ConstraintValidations::ClassMethods
- Sequel::Plugins::ConstraintValidations::DatabaseMethods
- Sequel::Plugins::ConstraintValidations::InstanceMethods
- Sequel::Plugins::DatasetAssociations
- Sequel::Plugins::DatasetAssociations::ClassMethods
- Sequel::Plugins::DatasetAssociations::DatasetMethods
- Sequel::Plugins::DefaultsSetter
- Sequel::Plugins::DefaultsSetter::ClassMethods
- Sequel::Plugins::DefaultsSetter::InstanceMethods
- Sequel::Plugins::Dirty
- Sequel::Plugins::Dirty::InstanceMethods
- Sequel::Plugins::EagerEach
- Sequel::Plugins::EagerEach::DatasetMethods
- Sequel::Plugins::ErrorSplitter
- Sequel::Plugins::ErrorSplitter::InstanceMethods
- Sequel::Plugins::ForceEncoding
- Sequel::Plugins::ForceEncoding::ClassMethods
- Sequel::Plugins::ForceEncoding::InstanceMethods
- Sequel::Plugins::HookClassMethods
- Sequel::Plugins::HookClassMethods::ClassMethods
- Sequel::Plugins::HookClassMethods::InstanceMethods
- Sequel::Plugins::InputTransformer
- Sequel::Plugins::InputTransformer::ClassMethods
- Sequel::Plugins::InputTransformer::InstanceMethods
- Sequel::Plugins::InstanceFilters
- Sequel::Plugins::InstanceFilters::Error
- Sequel::Plugins::InstanceFilters::InstanceMethods
- Sequel::Plugins::InstanceHooks
- Sequel::Plugins::InstanceHooks::InstanceMethods
- Sequel::Plugins::JsonSerializer
- Sequel::Plugins::JsonSerializer::ClassMethods
- Sequel::Plugins::JsonSerializer::DatasetMethods
- Sequel::Plugins::JsonSerializer::InstanceMethods
- Sequel::Plugins::JsonSerializer::Literal
- Sequel::Plugins::LazyAttributes
- Sequel::Plugins::LazyAttributes::ClassMethods
- Sequel::Plugins::LazyAttributes::InstanceMethods
- Sequel::Plugins::List
- Sequel::Plugins::List::ClassMethods
- Sequel::Plugins::List::InstanceMethods
- Sequel::Plugins::ManyThroughMany
- Sequel::Plugins::ManyThroughMany::ClassMethods
- Sequel::Plugins::ManyThroughMany::DatasetMethods
- Sequel::Plugins::ManyThroughMany::ManyThroughManyAssociationReflection
- Sequel::Plugins::ManyToOnePkLookup
- Sequel::Plugins::MssqlOptimisticLocking
- Sequel::Plugins::MssqlOptimisticLocking::ClassMethods
- Sequel::Plugins::MssqlOptimisticLocking::InstanceMethods
- Sequel::Plugins::NestedAttributes
- Sequel::Plugins::NestedAttributes::ClassMethods
- Sequel::Plugins::NestedAttributes::InstanceMethods
- Sequel::Plugins::OptimisticLocking
- Sequel::Plugins::OptimisticLocking::ClassMethods
- Sequel::Plugins::OptimisticLocking::Error
- Sequel::Plugins::OptimisticLocking::InstanceMethods
- Sequel::Plugins::PgArrayAssociations
- Sequel::Plugins::PgArrayAssociations::ClassMethods
- Sequel::Plugins::PgArrayAssociations::DatasetMethods
- Sequel::Plugins::PgArrayAssociations::ManyToPgArrayAssociationReflection
- Sequel::Plugins::PgArrayAssociations::PgArrayToManyAssociationReflection
- Sequel::Plugins::PgRow
- Sequel::Plugins::PgRow::ClassMethods
- Sequel::Plugins::PgRow::DatabaseMethods
- Sequel::Plugins::PgRow::InstanceMethods
- Sequel::Plugins::PgTypecastOnLoad
- Sequel::Plugins::PgTypecastOnLoad::ClassMethods
- Sequel::Plugins::PgTypecastOnLoad::InstanceMethods
- Sequel::Plugins::PreparedStatements
- Sequel::Plugins::PreparedStatements::ClassMethods
- Sequel::Plugins::PreparedStatements::InstanceMethods
- Sequel::Plugins::PreparedStatementsAssociations
- Sequel::Plugins::PreparedStatementsAssociations::ClassMethods
- Sequel::Plugins::PreparedStatementsAssociations::InstanceMethods
- Sequel::Plugins::PreparedStatementsSafe
- Sequel::Plugins::PreparedStatementsSafe::ClassMethods
- Sequel::Plugins::PreparedStatementsSafe::InstanceMethods
- Sequel::Plugins::PreparedStatementsWithPk
- Sequel::Plugins::PreparedStatementsWithPk::ClassMethods
- Sequel::Plugins::PreparedStatementsWithPk::DatasetMethods
- Sequel::Plugins::RcteTree
- Sequel::Plugins::Schema
- Sequel::Plugins::Schema::ClassMethods
- Sequel::Plugins::Scissors
- Sequel::Plugins::Scissors::ClassMethods
- Sequel::Plugins::Serialization
- Sequel::Plugins::Serialization::ClassMethods
- Sequel::Plugins::Serialization::InstanceMethods
- Sequel::Plugins::SerializationModificationDetection
- Sequel::Plugins::SerializationModificationDetection::InstanceMethods
- Sequel::Plugins::Sharding
- Sequel::Plugins::Sharding::ClassMethods
- Sequel::Plugins::Sharding::DatasetMethods
- Sequel::Plugins::Sharding::InstanceMethods
- Sequel::Plugins::SingleTableInheritance
- Sequel::Plugins::SingleTableInheritance::ClassMethods
- Sequel::Plugins::SingleTableInheritance::InstanceMethods
- Sequel::Plugins::SkipCreateRefresh
- Sequel::Plugins::SkipCreateRefresh::InstanceMethods
- Sequel::Plugins::StaticCache
- Sequel::Plugins::StaticCache::ClassMethods
- Sequel::Plugins::StaticCache::InstanceMethods
- Sequel::Plugins::StringStripper
- Sequel::Plugins::StringStripper::ClassMethods
- Sequel::Plugins::Subclasses
- Sequel::Plugins::Subclasses::ClassMethods
- Sequel::Plugins::TableSelect
- Sequel::Plugins::TableSelect::ClassMethods
- Sequel::Plugins::TacticalEagerLoading
- Sequel::Plugins::TacticalEagerLoading::DatasetMethods
- Sequel::Plugins::TacticalEagerLoading::InstanceMethods
- Sequel::Plugins::Timestamps
- Sequel::Plugins::Timestamps::ClassMethods
- Sequel::Plugins::Timestamps::InstanceMethods
- Sequel::Plugins::Touch
- Sequel::Plugins::Touch::ClassMethods
- Sequel::Plugins::Touch::InstanceMethods
- Sequel::Plugins::Tree
- Sequel::Plugins::Tree::ClassMethods
- Sequel::Plugins::Tree::InstanceMethods
- Sequel::Plugins::Tree::SingleRoot
- Sequel::Plugins::Tree::SingleRoot::ClassMethods
- Sequel::Plugins::Tree::SingleRoot::InstanceMethods
- Sequel::Plugins::Tree::TreeMultipleRootError
- Sequel::Plugins::TypecastOnLoad
- Sequel::Plugins::TypecastOnLoad::ClassMethods
- Sequel::Plugins::TypecastOnLoad::InstanceMethods
- Sequel::Plugins::UnlimitedUpdate
- Sequel::Plugins::UnlimitedUpdate::InstanceMethods
- Sequel::Plugins::UpdatePrimaryKey
- Sequel::Plugins::UpdatePrimaryKey::InstanceMethods
- Sequel::Plugins::ValidationClassMethods
- Sequel::Plugins::ValidationClassMethods::ClassMethods
- Sequel::Plugins::ValidationClassMethods::ClassMethods::Generator
- Sequel::Plugins::ValidationClassMethods::InstanceMethods
- Sequel::Plugins::ValidationHelpers
- Sequel::Plugins::ValidationHelpers::InstanceMethods
- Sequel::Plugins::XmlSerializer
- Sequel::Plugins::XmlSerializer::ClassMethods
- Sequel::Plugins::XmlSerializer::DatasetMethods
- Sequel::Plugins::XmlSerializer::InstanceMethods
- Sequel::PoolTimeout
- Sequel::Postgres
- Sequel::Postgres::Adapter
- Sequel::Postgres::AlterTableGenerator
- Sequel::Postgres::ArrayOp
- Sequel::Postgres::ArrayOpMethods
- Sequel::Postgres::CreateTableGenerator
- Sequel::Postgres::Database
- Sequel::Postgres::DatabaseMethods
- Sequel::Postgres::Dataset
- Sequel::Postgres::Dataset::ArgumentMapper
- Sequel::Postgres::Dataset::BindArgumentMethods
- Sequel::Postgres::Dataset::PreparedStatementMethods
- Sequel::Postgres::DatasetMethods
- Sequel::Postgres::DatasetMethods::PreparedStatementMethods
- Sequel::Postgres::ExclusionConstraintViolation
- Sequel::Postgres::HStore
- Sequel::Postgres::HStore::DatabaseMethods
- Sequel::Postgres::HStore::Parser
- Sequel::Postgres::HStoreOp
- Sequel::Postgres::HStoreOpMethods
- Sequel::Postgres::InetDatabaseMethods
- Sequel::Postgres::InetDatasetMethods
- Sequel::Postgres::IntervalDatabaseMethods
- Sequel::Postgres::IntervalDatabaseMethods::Parser
- Sequel::Postgres::IntervalDatasetMethods
- Sequel::Postgres::JSONArray
- Sequel::Postgres::JSONDatabaseMethods
- Sequel::Postgres::JSONHash
- Sequel::Postgres::JSONOp
- Sequel::Postgres::JSONOpMethods
- Sequel::Postgres::LooseCount
- Sequel::Postgres::PGArray
- Sequel::Postgres::PGArray::Creator
- Sequel::Postgres::PGArray::DatabaseMethods
- Sequel::Postgres::PGArray::JSONCreator
- Sequel::Postgres::PGArray::Parser
- Sequel::Postgres::PGRange
- Sequel::Postgres::PGRange::DatabaseMethods
- Sequel::Postgres::PGRange::DatasetMethods
- Sequel::Postgres::PGRange::Parser
- Sequel::Postgres::PGRow
- Sequel::Postgres::PGRow::ArrayRow
- Sequel::Postgres::PGRow::DatabaseMethods
- Sequel::Postgres::PGRow::HashRow
- Sequel::Postgres::PGRow::Parser
- Sequel::Postgres::PGRow::Splitter
- Sequel::Postgres::PGRowOp
- Sequel::Postgres::PGRowOp::ExpressionMethods
- Sequel::Postgres::RangeOp
- Sequel::Postgres::RangeOpMethods
- Sequel::Postgres::StaticCacheUpdater
- Sequel::PrettyTable
- Sequel::Progress
- Sequel::Progress::DatabaseMethods
- Sequel::Progress::DatasetMethods
- Sequel::Qualifier
- Sequel::QueryLiterals
- Sequel::Rollback
- Sequel::SQL
- Sequel::SQL::AliasMethods
- Sequel::SQL::AliasedExpression
- Sequel::SQL::BitwiseMethods
- Sequel::SQL::Blob
- Sequel::SQL::BooleanConstant
- Sequel::SQL::BooleanExpression
- Sequel::SQL::BooleanMethods
- Sequel::SQL::Builders
- Sequel::SQL::CaseExpression
- Sequel::SQL::Cast
- Sequel::SQL::CastMethods
- Sequel::SQL::ColumnAll
- Sequel::SQL::ComplexExpression
- Sequel::SQL::ComplexExpressionMethods
- Sequel::SQL::Constant
- Sequel::SQL::Constants
- Sequel::SQL::DateAdd
- Sequel::SQL::DateAdd::DatasetMethods
- Sequel::SQL::DelayedEvaluation
- Sequel::SQL::EmulatedFunction
- Sequel::SQL::Expression
- Sequel::SQL::Function
- Sequel::SQL::GenericExpression
- Sequel::SQL::Identifier
- Sequel::SQL::InequalityMethods
- Sequel::SQL::JoinClause
- Sequel::SQL::JoinOnClause
- Sequel::SQL::JoinUsingClause
- Sequel::SQL::NegativeBooleanConstant
- Sequel::SQL::NumericExpression
- Sequel::SQL::NumericMethods
- Sequel::SQL::OperatorBuilders
- Sequel::SQL::OrderMethods
- Sequel::SQL::OrderedExpression
- Sequel::SQL::PlaceholderLiteralString
- Sequel::SQL::QualifiedIdentifier
- Sequel::SQL::QualifyingMethods
- Sequel::SQL::StringConcatenationMethods
- Sequel::SQL::StringExpression
- Sequel::SQL::StringMethods
- Sequel::SQL::Subscript
- Sequel::SQL::SubscriptMethods
- Sequel::SQL::ValueList
- Sequel::SQL::VirtualRow
- Sequel::SQL::Window
- Sequel::SQL::WindowFunction
- Sequel::SQL::Wrapper
- Sequel::SQLTime
- Sequel::SQLite
- Sequel::SQLite::Database
- Sequel::SQLite::DatabaseMethods
- Sequel::SQLite::Dataset
- Sequel::SQLite::Dataset::ArgumentMapper
- Sequel::SQLite::Dataset::BindArgumentMethods
- Sequel::SQLite::Dataset::PreparedStatementMethods
- Sequel::SQLite::DatasetMethods
- Sequel::Schema
- Sequel::Schema::AlterTableGenerator
- Sequel::Schema::CreateTableGenerator
- Sequel::Schema::Generator
- Sequel::SchemaCaching
- Sequel::SchemaDumper
- Sequel::SelectRemove
- Sequel::Sequel3DatasetMethods
- Sequel::SerializationFailure
- Sequel::ServerBlock
- Sequel::SetOverrides
- Sequel::ShardedSingleConnectionPool
- Sequel::ShardedThreadedConnectionPool
- Sequel::SimpleMigration
- Sequel::SingleConnectionPool
- Sequel::SqlAnywhere
- Sequel::SqlAnywhere::Database
- Sequel::SqlAnywhere::DatabaseMethods
- Sequel::SqlAnywhere::Dataset
- Sequel::SqlAnywhere::DatasetMethods
- Sequel::SqlAnywhere::SQLAnywhereException
- Sequel::Swift
- Sequel::Swift::Database
- Sequel::Swift::Dataset
- Sequel::Swift::MySQL
- Sequel::Swift::MySQL::DatabaseMethods
- Sequel::Swift::MySQL::Dataset
- Sequel::Swift::Postgres
- Sequel::Swift::Postgres::DatabaseMethods
- Sequel::Swift::SQLite
- Sequel::Swift::SQLite::DatabaseMethods
- Sequel::Swift::SQLite::Dataset
- Sequel::ThreadLocalTimezones
- Sequel::ThreadedConnectionPool
- Sequel::ThreadedServerBlock
- Sequel::TimestampMigrator
- Sequel::Timezones
- Sequel::TinyTDS
- Sequel::TinyTDS::Database
- Sequel::TinyTDS::Dataset
- Sequel::TinyTDS::Dataset::ArgumentMapper
- Sequel::TinyTDS::Dataset::PreparedStatementMethods
- Sequel::ToDot
- Sequel::ToDot::DatasetMethods
- Sequel::UnbindDuplicate
- Sequel::Unbinder
- Sequel::UndefinedAssociation
- Sequel::UniqueConstraintViolation
- Sequel::UnthreadedServerBlock
- Sequel::ValidationFailed
- String
- String::Inflections
- Array
- FalseClass
- Hash
- NilClass
- Numeric
- Object
- PGconn
- PGresult
- Range
- Symbol
- TrueClass

No matching classes.

# Cheat Sheet

## Open a database

    require 'sequel'

    DB = Sequel.sqlite('my_blog.db')
    DB = Sequel.connect('postgres://user:password@localhost/my_db')
    DB = Sequel.postgres('my_db', :user => 'user', :password => 'password', :host => 'localhost')
    DB = Sequel.ado('mydb')

## Open an SQLite memory database

Without a filename argument, the sqlite adapter will setup a new sqlite database in memory.

    DB = Sequel.sqlite

## Logging SQL statements

    require 'logger'
    DB = Sequel.sqlite '', :loggers => [Logger.new($stdout)]
    # or
    DB.loggers << Logger.new(...)

## Using raw SQL

    DB.run "CREATE TABLE users (name VARCHAR(255) NOT NULL, age INT(3) NOT NULL)"
    dataset = DB["SELECT age FROM users WHERE name = ?", name]
    dataset.map(:age)
    DB.fetch("SELECT name FROM users") do |row|
      p row[:name]
    end

## Create a dataset

    dataset = DB[:items]
    dataset = DB.from(:items)

## Most dataset methods are chainable

    dataset = DB[:managers].where(:salary => 5000..10000).order(:name, :department)

## Insert rows

    dataset.insert(:name => 'Sharon', :grade => 50)

## Retrieve rows

    dataset.each{|r| p r}
    dataset.all # => [{...}, {...}, ...]
    dataset.first # => {...}

## Update/Delete rows

    dataset.exclude(:active).delete
    dataset.where('price < ?', 100).update(:active => true)

## Datasets are Enumerable

    dataset.map{|r| r[:name]}
    dataset.map(:name) # same as above

    dataset.inject(0){|sum, r| sum + r[:value]}
    dataset.sum(:value) # better

## Filtering (see also Dataset Filtering)

### Equality

    dataset.where(:name => 'abc')
    dataset.where('name = ?', 'abc')

### Inequality

    dataset.where{value > 100}
    dataset.exclude{value <= 100}

### Inclusion

    dataset.where(:value => 50..100)
    dataset.where{(value >= 50) & (value <= 100)}

    dataset.where('value IN ?', [50,75,100])
    dataset.where(:value=>[50,75,100])

    dataset.where(:id=>other_dataset.select(:other_id))

### Subselects as scalar values

    dataset.where('price > (SELECT avg(price) + 100 FROM table)')
    dataset.where{price > dataset.select(avg(price) + 100)}

### LIKE/Regexp

    DB[:items].where(Sequel.like(:name, 'AL%'))
    DB[:items].where(:name => /^AL/)

### AND/OR/NOT

    DB[:items].where{(x > 5) & (y > 10)}.sql
    # SELECT * FROM items WHERE ((x > 5) AND (y > 10))

    DB[:items].where(Sequel.or(:x => 1, :y => 2)) & Sequel.~(:z => 3)).sql
    # SELECT * FROM items WHERE (((x = 1) OR (y = 2)) AND (z != 3))

### Mathematical operators

    DB[:items].where{x + y > z}.sql
    # SELECT * FROM items WHERE ((x + y) > z)

    DB[:items].where{price - 100 < avg(price)}.sql
    # SELECT * FROM items WHERE ((price - 100) < avg(price))

## Ordering

    dataset.order(:kind)
    dataset.reverse_order(:kind)
    dataset.order(Sequel.desc(:kind), :name)

## Limit/Offset

    dataset.limit(30) # LIMIT 30
    dataset.limit(30, 10) # LIMIT 30 OFFSET 10
    dataset.limit(30).offset(10) # LIMIT 30 OFFSET 10

## Joins

    DB[:items].left_outer_join(:categories, :id => :category_id).sql
    # SELECT * FROM items
    # LEFT OUTER JOIN categories ON categories.id = items.category_id

    DB[:items].join(:categories, :id => :category_id).join(:groups, :id => :items__group_id)
    # SELECT * FROM items
    # INNER JOIN categories ON categories.id = items.category_id
    # INNER JOIN groups ON groups.id = items.group_id

## Aggregate functions methods

    dataset.count #=> record count
    dataset.max(:price)
    dataset.min(:price)
    dataset.avg(:price)
    dataset.sum(:stock)

    dataset.group_and_count(:category)
    dataset.select_group(:category).select_append{avg(:price)}

## SQL Functions / Literals

    dataset.update(:updated_at => Sequel.function(:NOW))
    dataset.update(:updated_at => Sequel.lit('NOW()'))

    dataset.update(:updated_at => Sequel.lit("DateValue('1/1/2001')")
    dataset.update(:updated_at => Sequel.function(:DateValue, '1/1/2001'))

## Schema Manipulation

    DB.create_table :items do
      primary_key :id
      String :name, :unique => true, :null => false
      TrueClass :active, :default => true
      foreign_key :category_id, :categories
      DateTime :created_at

      index :created_at
    end

    DB.drop_table :items

## Aliasing

    DB[:items].select(Sequel.as(:name, :item_name))
    DB[:items].select(:name___item_name)
    DB[:items___items_table].select(:items_table__name___item_name)
    # SELECT items_table.name AS item_name FROM items AS items_table

## Transactions

    DB.transaction do
      dataset.insert(:first_name => 'Inigo', :last_name => 'Montoya')
      dataset.insert(:first_name => 'Farm', :last_name => 'Boy')
    end # Either both are inserted or neither are inserted

Database#transaction is re-entrant:

    DB.transaction do # BEGIN issued only here
      DB.transaction
        dataset << {:first_name => 'Inigo', :last_name => 'Montoya'}
      end
    end # COMMIT issued only here

Transactions are aborted if an error is raised:

    DB.transaction do
      raise "some error occurred"
    end # ROLLBACK issued and the error is re-raised

Transactions can also be aborted by raising Sequel::Rollback:

    DB.transaction do
      raise(Sequel::Rollback) if something_bad_happened
    end # ROLLBACK issued and no error raised

Savepoints can be used if the database supports it:

    DB.transaction do
      dataset << {:first_name => 'Farm', :last_name => 'Boy'} # Inserted
      DB.transaction(:savepoint=>true) # This savepoint is rolled back
        dataset << {:first_name => 'Inigo', :last_name => 'Montoya'} # Not inserted
        raise(Sequel::Rollback) if something_bad_happened
      end
      dataset << {:first_name => 'Prince', :last_name => 'Humperdink'} # Inserted
    end

## Miscellaneous:

    dataset.sql # "SELECT * FROM items"
    dataset.delete_sql # "DELETE FROM items"
    dataset.where(:name => 'sequel').exists # "EXISTS ( SELECT * FROM items WHERE name = 'sequel' )"
    dataset.columns #=> array of columns in the result set, does a SELECT
    DB.schema(:items) => [[:id, {:type=>:integer, ...}], [:name, {:type=>:string, ...}], ...]

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