weka.experiment
Class InstanceQuery

java.lang.Object
  |
  +--weka.experiment.DatabaseUtils
        |
        +--weka.experiment.InstanceQuery

All Implemented Interfaces:

OptionHandler, java.io.Serializable

public class InstanceQuery

extends DatabaseUtils

implements OptionHandler

Convert the results of a database query into instances. The jdbc driver and database to be used default to "jdbc.idbDriver" and "jdbc:idb=experiments.prp". These may be changed by creating a java properties file called DatabaseUtils.props in user.home or the current directory. eg:

 jdbcDriver=jdbc.idbDriver
 jdbcURL=jdbc:idb=experiments.prp
 

Command line use just outputs the instances to System.out.

Version:

$Revision: 1.15 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

Fields inherited from class weka.experiment.DatabaseUtils

BOOL, BYTE, DATE, DOUBLE, EXP_INDEX_TABLE, EXP_RESULT_COL, EXP_RESULT_PREFIX, EXP_SETUP_COL, EXP_TYPE_COL, FLOAT, INTEGER, LONG, SHORT, STRING

Constructor Summary

InstanceQuery()
Sets up the database drivers

Method Summary

java.lang.String[]	getOptions() Gets the current settings of InstanceQuery
java.lang.String	getQuery() Get the query to execute against the database
boolean	getSparseData() Gets whether data is to be returned as a set of sparse instances
java.util.Enumeration	listOptions() Returns an enumeration describing the available options
static void	main(java.lang.String[] args) Test the class from the command line.
java.lang.String	queryTipText() Returns the tip text for this property
Instances	retrieveInstances() Makes a database query using the query set through the -Q option to convert a table into a set of instances
Instances	retrieveInstances(java.lang.String query) Makes a database query to convert a table into a set of instances
void	setOptions(java.lang.String[] options) Parses a given list of options.
void	setQuery(java.lang.String q) Set the query to execute against the database
void	setSparseData(boolean s) Sets whether data should be encoded as sparse instances
java.lang.String	sparseDataTipText() Returns the tip text for this property

Methods inherited from class weka.experiment.DatabaseUtils

arrayToString, connectToDatabase, createExperimentIndex, createExperimentIndexEntry, createResultsTable, databaseURLTipText, disconnectFromDatabase, execute, experimentIndexExists, getDatabaseURL, getPassword, getResultFromTable, getResultSet, getResultsTableName, getUsername, isConnected, putResultInTable, setDatabaseURL, setPassword, setUsername, tableExists, typeName

Methods inherited from class java.lang.Object

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

Constructor Detail

InstanceQuery

public InstanceQuery()
              throws java.lang.Exception

Sets up the database drivers

Throws:

java.lang.Exception - if an error occurs

Method Detail

listOptions

public java.util.Enumeration listOptions()

Returns an enumeration describing the available options

Specified by:

listOptions in interface OptionHandler

Returns:

an enumeration of all available options.

setOptions

public void setOptions(java.lang.String[] options)
                throws java.lang.Exception

Parses a given list of options. Valid options are:

-S
Return a set of sparse instances rather than normal instances.

Specified by:

setOptions in interface OptionHandler

Parameters:

options - the list of options as an array of strings

Throws:

java.lang.Exception - if an option is not supported

queryTipText

public java.lang.String queryTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

setQuery

public void setQuery(java.lang.String q)

Set the query to execute against the database

Parameters:

q - the query to execute

getQuery

public java.lang.String getQuery()

Get the query to execute against the database

Returns:

the query

sparseDataTipText

public java.lang.String sparseDataTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

setSparseData

public void setSparseData(boolean s)

Sets whether data should be encoded as sparse instances

Parameters:

s - true if data should be encoded as a set of sparse instances

getSparseData

public boolean getSparseData()

Gets whether data is to be returned as a set of sparse instances

Returns:

true if data is to be encoded as sparse instances

getOptions

public java.lang.String[] getOptions()

Gets the current settings of InstanceQuery

Specified by:

getOptions in interface OptionHandler

Returns:

an array of strings suitable for passing to setOptions()

retrieveInstances

public Instances retrieveInstances()
                            throws java.lang.Exception

Makes a database query using the query set through the -Q option to convert a table into a set of instances

Returns:

the instances contained in the result of the query

Throws:

java.lang.Exception - if an error occurs

retrieveInstances

public Instances retrieveInstances(java.lang.String query)
                            throws java.lang.Exception

Makes a database query to convert a table into a set of instances

Parameters:

query - the query to convert to instances

Returns:

the instances contained in the result of the query

Throws:

java.lang.Exception - if an error occurs

main

public static void main(java.lang.String[] args)

Test the class from the command line. The instance query should be specified with -Q sql_query

Parameters:

args - contains options for the instance query