Class DeephavenCommand

Executes ad-hoc Deephaven queries against a Deephaven Open API server.

Inheritance

System.Object

DeephavenCommand

Namespace: Deephaven.Connector

Assembly: Deephaven.Connector.dll

Syntax

public sealed class DeephavenCommand : DbCommand

Remarks

Unlike most ADO.NET implementations, this does not accept SQL queries/commands. Groovy and Python query expressions are accepted, depending on the session type specified when the DeephavenConnection is created. When ExecuteDbDataReader(CommandBehavior) is called, the query or queries specied in CommandText are sent to the server for execution, and a snapshot of the result(s) produced. The query results can be iterated using the standard methods.

Constructors

DeephavenCommand()

Constructs an instance of the DeephavenCommand object.

Declaration

public DeephavenCommand()

DeephavenCommand(DbConnection)

Constructs an instance of the DeephavenCommand object with the given connection. The connection should be an instance of DeephavenConnection.

Declaration

public DeephavenCommand(DbConnection dbConnection)

Parameters

Type	Name	Description
DbConnection	dbConnection	The DeephavenConnection to use.

DeephavenCommand(String, DbConnection)

Constructs an instance of the DeephavenCommand object with the given command text and connection. The connection should be an instance of DeephavenConnection.

Declaration

public DeephavenCommand(string commandText, DbConnection dbConnection)

Parameters

Type	Name	Description
System.String	commandText	The command text in the appropriate language for the session type.
DbConnection	dbConnection	The DeephavenConnection to use.

Properties

CommandText

The command text in the appropriate language for the session type.

Declaration

public override string CommandText { get; set; }

Property Value

Type	Description
System.String

CommandTimeout

The maximum time to wait when executing this query in seconds. Default is 600 (10 minutes). You may need to increase this parameter for complex or very large queries.

Declaration

public override int CommandTimeout { get; set; }

Property Value

Type	Description
System.Int32

CommandType

The command type. Only text commands are supported at this time.

Declaration

public override CommandType CommandType { get; set; }

Property Value

Type	Description
CommandType

DbConnection

Gets or sets the DbConnection used by this DbCommand. Must be a DeephavenConnection instance.

Declaration

protected override DbConnection DbConnection { get; set; }

Property Value

Type	Description
DbConnection

DbParameterCollection

Gets the collection of DbParameter objects.

Declaration

protected override DbParameterCollection DbParameterCollection { get; }

Property Value

Type	Description
DbParameterCollection

DbTransaction

Gets or sets the DbTransaction within which this object executes. Since transactions are not presently supported, must be null.

Declaration

protected override DbTransaction DbTransaction { get; set; }

Property Value

Type	Description
DbTransaction

DesignTimeVisible

Gets or sets a value indicating whether the command object should be visible in a customized interface control.

Declaration

public override bool DesignTimeVisible { get; set; }

Property Value

Type	Description
System.Boolean

UpdatedRowSource

Gets or sets how command results are applied to the DataRow when used by the Update method of a DbDataAdapter. Since updates are not presently supported, only is supported.

Declaration

public override UpdateRowSource UpdatedRowSource { get; set; }

Property Value

Type	Description
UpdateRowSource

Methods

Cancel()

Attempts to cancel the execution of a . Not presently supported.

Declaration

public override void Cancel()

CreateDbParameter()

Creates a new instance of a DeephavenParameter object.

Declaration

protected override DbParameter CreateDbParameter()

Returns

Type	Description
DbParameter	A DeephavenParameter object.

ExecuteDbDataReader(CommandBehavior)

Executes the command text against the connection.

Declaration

protected override DbDataReader ExecuteDbDataReader(CommandBehavior behavior)

Parameters

Type	Name	Description
CommandBehavior	behavior	An instance of .

Returns

Type	Description
DbDataReader	A task representing the operation.

ExecuteNonQuery()

Executes a statement against a connection object. Not presently supported.

Declaration

public override int ExecuteNonQuery()

Returns

Type	Description
System.Int32

ExecuteScalar()

Executes the query and returns the first column of the first row in the result set returned by the query. All other columns and rows are ignored. Not presently supported.

Declaration

public override object ExecuteScalar()

Returns

Type	Description
System.Object	The first column of the first row in the result set.

Prepare()

Creates a prepared (or compiled) version of the command on the data source. Not presently supported.

Declaration

public override void Prepare()