Interface IStatement

An executable query. This represents either a SimpleStatement, a BoundStatement or a BoundStatement along with the query options (consistency level, whether to trace the query, ...).

Namespace: Cassandra

Assembly: Cassandra.dll

Syntax

public interface IStatement

Properties

AutoPage

Determines if the RowSet returned when executing this IStatement will automatically fetch the following result pages. Defaults to true.

Declaration

bool AutoPage { get; }

Property Value

Type	Description
bool

ConsistencyLevel

Gets the consistency level for this query.

Declaration

ConsistencyLevel? ConsistencyLevel { get; }

Property Value

Type	Description
ConsistencyLevel?

IsIdempotent

Determines if this statement is idempotent, i.e. whether it can be applied multiple times without changing the result beyond the initial application.

Idempotence of the statement plays a role in ISpeculativeExecutionPolicy. If a statement is not idempotent, the driver will not schedule speculative executions for it.

When the property is null, the driver will use the default value from the GetDefaultIdempotence().

Declaration

bool? IsIdempotent { get; }

Property Value

Type	Description
bool?

IsTracing

Gets whether tracing is enabled for this query or not.

Declaration

bool IsTracing { get; }

Property Value

Type	Description
bool

Keyspace

Returns the keyspace this query operates on.

Note that not all Statement implementations specify on which keyspace they operate on so this method can return null. If null, it will operate on the default keyspace set during initialization (if it was set).

The keyspace returned is used as a hint for token-aware routing.

Declaration

string Keyspace { get; }

Property Value

Type	Description
string

Remarks

Consider using a ISession connected to single keyspace using Connect(string).

OutgoingPayload

Gets custom payload for that will be included when executing this Statement.

Declaration

IDictionary<string, byte[]> OutgoingPayload { get; }

Property Value

Type	Description
IDictionary<string, byte[]>

PageSize

Gets query's page size.

Declaration

int PageSize { get; }

Property Value

Type	Description
int

PagingState

This object represents the next page to be fetched if the query is multi page. It can be saved and reused later on a different execution.

Declaration

byte[] PagingState { get; }

Property Value

Type	Description
byte[]

QueryValues

Declaration

object[] QueryValues { get; }

Property Value

Type	Description
object[]

ReadTimeoutMillis

Gets the per-host read timeout for this statement.

When the value is 0 or lower, the default value from the socket options will be used.

Declaration

int ReadTimeoutMillis { get; }

Property Value

Type	Description
int

RetryPolicy

Gets the retry policy sets for this query, if any.

Declaration

IRetryPolicy RetryPolicy { get; }

Property Value

Type	Description
IRetryPolicy

RoutingKey

The routing key (in binary raw form) to use for token aware routing of this query.

The routing key is optional in the sense that implementers are free to return null. The routing key is an hint used for token aware routing (see

TokenAwarePolicy), and if provided should correspond to the binary value for the query partition key. However, not providing a routing key never causes a query to fail and if the load balancing policy used is not token aware, then the routing key can be safely ignored.

Declaration

RoutingKey RoutingKey { get; }

Property Value

Type	Description
RoutingKey

SerialConsistencyLevel

Gets the serial consistency level for the query.

The serial consistency level is only used by conditional updates (INSERT, UPDATE and DELETE with an IF condition).

Declaration

ConsistencyLevel SerialConsistencyLevel { get; }

Property Value

Type	Description
ConsistencyLevel

SkipMetadata

Declaration

bool SkipMetadata { get; }

Property Value

Type	Description
bool

Timestamp

Gets the timestamp associated with this statement execution.

Declaration

DateTimeOffset? Timestamp { get; }

Property Value

Type	Description
DateTimeOffset?

Methods

DisableTracing()

Disable tracing for the statement.

Declaration

IStatement DisableTracing()

Returns

Type	Description
IStatement

EnableTracing(bool)

Enables tracing for the statement

Declaration

IStatement EnableTracing(bool enable = true)

Parameters

Type	Name	Description
bool	enable

Returns

Type	Description
IStatement

ExecutingAs(string)

Allows this statement to be executed as a different user/role than the one currently authenticated (a.k.a. proxy execution).

Declaration

IStatement ExecutingAs(string userOrRole)

Parameters

Type	Name	Description
string	userOrRole	The user or role name to act as when executing this statement.

Returns

Type	Description
IStatement	This statement

Remarks

This feature is only available in DSE 5.1+.

SetAutoPage(bool)

Sets the paging behavior. When set to true (default), the RowSet returned when executing this IStatement will automatically fetch the following result pages. When false, the RowSet returned will only contain the rows contained in the result page and will not fetch additional pages.

Declaration

IStatement SetAutoPage(bool autoPage)

Parameters

Type	Name	Description
bool	autoPage

Returns

Type	Description
IStatement	this IStatement object.

SetConsistencyLevel(ConsistencyLevel?)

Sets the consistency level for the query.

The default consistency level, if this method is not called, is ConsistencyLevel.ONE.

Declaration

IStatement SetConsistencyLevel(ConsistencyLevel? consistency)

Parameters

Type	Name	Description
ConsistencyLevel?	consistency	the consistency level to set.

Returns

Type	Description
IStatement	this IStatement object.

SetIdempotence(bool)

Sets whether this statement is idempotent.

Idempotence of the statement plays a role in ISpeculativeExecutionPolicy. If a statement is not idempotent, the driver will not schedule speculative executions for it.

Declaration

IStatement SetIdempotence(bool value)

Parameters

Type	Name	Description
bool	value

Returns

Type	Description
IStatement

SetOutgoingPayload(IDictionary<string, byte[]>)

Sets a custom outgoing payload for this statement. Each time this statement is executed, this payload will be included in the request. Once it is set using this method, the payload should not be modified.

Declaration

IStatement SetOutgoingPayload(IDictionary<string, byte[]> payload)

Parameters

Type	Name	Description
IDictionary<string, byte[]>	payload

Returns

Type	Description
IStatement

SetPageSize(int)

Sets the page size for this query. The page size controls how much resulting rows will be retrieved simultaneously (the goal being to avoid loading too much results in memory for queries yielding large results). Please note that while value as low as 1 can be used, it is highly discouraged to use such a low value in practice as it will yield very poor performance. If in doubt, leaving the default is probably a good idea.

Also note that only SELECT queries ever make use of that setting.

the page size to use. If set to 0 or less, the default value will be used. To disable paging of the result set, use int.MaxValuethis Query object.

Declaration

IStatement SetPageSize(int pageSize)

Parameters

Type	Name	Description
int	pageSize

Returns

Type	Description
IStatement

SetPagingState(byte[])

Sets the paging state, a token representing the current page state of query used to continue paging by retrieving the following result page. Setting the paging state will disable automatic paging.

Declaration

IStatement SetPagingState(byte[] pagingState)

Parameters

Type	Name	Description
byte[]	pagingState	The page state token

Returns

Type	Description
IStatement	this IStatement object.

SetReadTimeoutMillis(int)

Overrides the default per-host read timeout ReadTimeoutMillis for this statement.

Declaration

IStatement SetReadTimeoutMillis(int timeout)

Parameters

Type	Name	Description
int	timeout	Timeout in milliseconds. If the value is not greater than zero, the default value from the socket options will be used.

Returns

Type	Description
IStatement

SetRetryPolicy(IRetryPolicy)

Sets the retry policy to use for this query.

Calling this method is only required when you want to override the default RetryPolicy set in the cluster configuration for this request or the one set in the execution profile (see RetryPolicy) for this request.

Use a IExtendedRetryPolicy implementation to cover all error scenarios.

Declaration

IStatement SetRetryPolicy(IRetryPolicy policy)

Parameters

Type	Name	Description
IRetryPolicy	policy	The retry policy to use for this query.

Returns

Type	Description
IStatement	this IStatement instance.

SetSerialConsistencyLevel(ConsistencyLevel)

Sets the serial consistency level for the query. The serial consistency level is only used by conditional updates (so INSERT, UPDATE and DELETE with an IF condition). For those, the serial consistency level defines the consistency level of the serial phase (or "paxos" phase) while the normal consistency level defines the consistency for the "learn" phase, i.e. what type of reads will be guaranteed to see the update right away. For instance, if a conditional write has a regular consistency of QUORUM (and is successful), then a QUORUM read is guaranteed to see that write. But if the regular consistency of that write is ANY, then only a read with a consistency of SERIAL is guaranteed to see it (even a read with consistency ALL is not guaranteed to be enough).

Declaration

IStatement SetSerialConsistencyLevel(ConsistencyLevel serialConsistency)

Parameters

Type	Name	Description
ConsistencyLevel	serialConsistency	Can be set only to ConsistencyLevel.Serial or ConsistencyLevel.LocalSerial. Setting it to ConsistencyLevel.Serial guarantees full linearizability while ConsistencyLevel.LocalSerial guarantees it only in the local datacenter.

Returns

Type	Description
IStatement	this IStatement object.

SetTimestamp(DateTimeOffset)

Sets the timestamp associated with this statement execution. If provided, this will replace the server side assigned timestamp as default timestamp. Note that a timestamp in the query itself will still override this timestamp.

Declaration

IStatement SetTimestamp(DateTimeOffset value)

Parameters

Type	Name	Description
DateTimeOffset	value

Returns

Type	Description
IStatement