com.buabook.kdb.query

Class KdbQuery

java.lang.Object

com.buabook.kdb.query.KdbQuery

All Implemented Interfaces:

AutoCloseable

Direct Known Subclasses:

KdbAsyncQuery, KdbSyncQuery

public abstract class KdbQuery
extends Object
implements AutoCloseable

KDB Query Class (Abstract)

Contains base connectivity (wrapping KdbConnection) and some wrapper functions around the abstract query(String) function (c) 2014 - 2015 Sport Trades Ltd

Since:

8 Jun 2014

Version:

1.0.1

Author:

Jas Rajasansir

Field Summary

Fields

Modifier and Type	Field and Description
(package private) KdbConnection	connection The connection to use to query the kdb process

Constructor Summary

Constructors

Constructor and Description
KdbQuery(KdbConnection existingConnection) Constructs a new query object, re-using the specified connection object.
KdbQuery(KdbProcess target) Constructs a new query object, first opening an connection to the specified process

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying kdb connection
abstract Object	query(String query) Method to query a kdb process with a string argument only.
abstract Object	query(String query, KdbDict arguments) Method to query a kdb process with a function name and a dictionary argument.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

connection

KdbConnection connection

The connection to use to query the kdb process

Constructor Detail

KdbQuery

public KdbQuery(KdbProcess target)
         throws KdbTargetProcessUnavailableException

Constructs a new query object, first opening an connection to the specified process

Parameters:

target - The kdb process to connect to, ready for querying

Throws:

KdbTargetProcessUnavailableException - If the process is unavailable

KdbQuery

public KdbQuery(KdbConnection existingConnection)
         throws KdbTargetProcessUnavailableException

Constructs a new query object, re-using the specified connection object. If the connection is not currently active then a connection attempt is made. NOTE: You should not use the same connection object across multiple threads as data corruption is likely to occur.

Parameters:

existingConnection - The existing connection object to use.

Throws:

KdbTargetProcessUnavailableException

Method Detail

close

public void close()

Closes the underlying kdb connection

Specified by:

close in interface AutoCloseable

See Also:

KdbConnection.disconnect()

query

public abstract Object query(String query)
                      throws QueryExecutionFailedException

Method to query a kdb process with a string argument only. Example: "aFunction[]" or "aFunctionWithArgs[1;`symbol].

Parameters:

query - The string query to execute

Returns:

The query result

Throws:

QueryExecutionFailedException - If the query fails for any reason

query

public abstract Object query(String query,
                             KdbDict arguments)
                      throws QueryExecutionFailedException

Method to query a kdb process with a function name and a dictionary argument.

Parameters:

query - The function to execute

arguments - The dictionary of arguments

Returns:

The query result

Throws:

QueryExecutionFailedException - If the query fails for any reason