class Cassandra::Session

Returns current keyspace

Returns:

Type	Details
String	current keyspace

Executes a given statement and returns a future result

Note

Positional arguments for simple statements are only supported starting with Apache Cassandra 2.0 and above.

Note

Named arguments for simple statements are only supported starting with Apache Cassandra 2.1 and above.

Parameters:

Name	Type	Details
statement	(String, Statements::Simple, Statements::Bound or Statements::Prepared)	statement to execute
options	Hash	(defaults to: nil) (nil) a customizable set of options

Keys for options:

Key	Type	Details
:consistency	Symbol	consistency level for the request. Must be one of CONSISTENCIES. Defaults to the setting in the active execution profile. If none is specified, the default profile is used, which is set to :local_one.
:page_size	Integer	size of results page. You can page through results using Result#next_page or Result#next_page_async
:trace	Boolean	default: false whether to enable request tracing
:timeout	Numeric	default: nil if specified, it is a number of seconds after which to time out the request if it hasn’t completed. Defaults to the setting in the active execution profile. If none is specified, the default profile is used, which is set to 12 seconds.
:serial_consistency	Symbol	default: nil this option is only relevant for conditional updates and specifies a serial consistency to be used, one of SERIAL_CONSISTENCIES
:paging_state	String	default: nil this option is used for stateless paging, where result paging is resumed some time after the initial request.
:arguments	(Array or Hash)	default: nil positional or named arguments for the statement.
:type_hints	(Array or Hash)	default: nil override Util.guess_type to determine the CQL type for an argument; nil elements will fall-back to Util.guess_type.
:idempotent	Boolean	default: false specify whether this statement can be retried safely on timeout.
:payload	Hash<[String, Symbol], String>	default: nil custom outgoing payload to be sent with the request.
:execution_profile	(String or Symbol)	default: nil name of Execution::Profile from which to obtain certain query options. Defaults to the cluster’s default execution profile.

Returns:

Type	Details
Future<Result>

See Also:

• Options that can be specified on the cluster-level and their default values.
• A list of errors this future can be resolved with

Specifications:

Session#execute_async should error out if a bad profile name is provided

expect {
          session.execute_async('SELECT * FROM songs', execution_profile: :bad_profile).get
        }.to raise_error(ArgumentError)

A blocking wrapper around #execute_async

Parameters:

Name	Type	Details
statement	(String, Statements::Simple, Statements::Bound or Statements::Prepared)	statement to execute
options	Hash	(defaults to: nil) (nil) a customizable set of options. See #execute_async for details.

Returns:

Type	Details
Result	query result

Raises:

Type	Details
Errors::NoHostsAvailable	if all hosts fail
Errors::ExecutionError	if Cassandra fails to execute
Errors::ValidationError	if Cassandra fails to validate
Errors::TimeoutError	if request has not completed within the :timeout given

See Also:

• #execute_async
• Future#get

Prepares a given statement and returns a future prepared statement

Parameters:

Name	Type	Details
statement	(String or Statements::Simple)	a statement to prepare
options	Hash	(defaults to: nil) (nil) a customizable set of options

Keys for options:

Key	Type	Details
:trace	Boolean	default: false whether to enable request tracing
:timeout	Numeric	default: nil if specified, it is a number of seconds after which to time out the request if it hasn’t completed
:idempotent	Boolean	default: false specify whether the statement being prepared can be retried safely on timeout during execution.
:execution_profile	(String or Symbol)	default: nil name of Execution::Profile from which to obtain certain query options. Defaults to the cluster’s default execution profile.

Returns:

Type	Details
Future<Statements::Prepared>	future prepared statement

Specifications:

Session#prepare_async should error out if a bad profile name is provided

expect {
          session.prepare_async('SELECT * FROM songs', execution_profile: :bad_profile).get
        }.to raise_error(ArgumentError)

A blocking wrapper around #prepare_async

Parameters:

Name	Type	Details
statement	(String or Statements::Simple)	a statement to prepare
options	Hash	(defaults to: nil) (nil) a customizable set of options. See #prepare_async for details.

Returns:

Type	Details
Statements::Prepared	prepared statement

Raises:

Type	Details
Errors::NoHostsAvailable	if none of the hosts can be reached
Errors::ExecutionError	if Cassandra returns an error response

See Also:

• #prepare_async
• Future#get

Specifications:

Session#prepare resolves a promise returned by #prepare_async

expect(session).to receive(:prepare_async).with(statement, nil).and_return(promise)
expect(promise).to receive(:get).once
session.prepare(statement)

Returns a logged Statements::Batch instance and optionally yields it to a given block

Yield Parameters:

Name	Type	Details
batch	Statements::Batch	a logged batch

Returns:

Type	Details
Statements::Batch	a logged batch

Returns a unlogged Statements::Batch instance and optionally yields it to a given block

Yield Parameters:

Name	Type	Details
batch	Statements::Batch	an unlogged batch

Returns:

Type	Details
Statements::Batch	an unlogged batch

Specifications:

Session#unlogged_batch creates an unlogged batch

batch = double('batch')
expect(Statements::Batch::Unlogged).to receive(:new).once.and_return(batch)
expect(session.unlogged_batch).to eq(batch)

Returns a counter Statements::Batch instance and optionally yields it to a given block

Yield Parameters:

Name	Type	Details
batch	Statements::Batch	a counter batch

Returns:

Type	Details
Statements::Batch	a counter batch

Specifications:

Session#counter_batch creates a counter batch

batch = double('batch')
expect(Statements::Batch::Counter).to receive(:new).once.and_return(batch)
expect(session.counter_batch).to eq(batch)

Asynchronously closes current session

Returns:

Type	Details
Future<Session>	a future that resolves to self once closed

Specifications:

Session#close_async uses Client#close

expect(client).to receive(:close).and_return(Ione::Future.resolved)
expect(session.close_async).to eq(promise)
expect(promise).to have_received(:fulfill).once.with(session)

Synchronously closes current session

Returns:

Type	Details
self	this session

See Also:

• #close_async

Specifications:

Session#close resolves a promise returned by #close_async

expect(session).to receive(:close_async).with(no_args).and_return(promise)
expect(promise).to receive(:get).once.and_return('success')
expect(session.close).to eq('success')