org.h2.samples

Class FunctionMultiReturn

java.lang.Object

org.h2.samples.FunctionMultiReturn

public class FunctionMultiReturn
extends java.lang.Object

User defined functions can return a result set, and can therefore be used like a table. This sample application uses such a function to convert polar to cartesian coordinates.

Constructor Summary

Constructors

Constructor and Description
FunctionMultiReturn()

Method Summary

Modifier and Type	Method and Description
static void	main(java.lang.String... args) This method is called when executing this sample application from the command line.
static java.sql.ResultSet	polar2Cartesian(java.lang.Double r, java.lang.Double alpha) Convert polar coordinates to cartesian coordinates.
static java.lang.Object[]	polar2CartesianArray(java.lang.Double r, java.lang.Double alpha) Convert polar coordinates to cartesian coordinates.
static java.sql.ResultSet	polar2CartesianSet(java.sql.Connection conn, java.lang.String query) Convert a set of polar coordinates to cartesian coordinates.

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionMultiReturn

public FunctionMultiReturn()

Method Detail

main

public static void main(java.lang.String... args)
                 throws java.lang.Exception

This method is called when executing this sample application from the command line.

Parameters:

args - the command line parameters

Throws:

java.lang.Exception

polar2Cartesian

public static java.sql.ResultSet polar2Cartesian(java.lang.Double r,
                                                 java.lang.Double alpha)

Convert polar coordinates to cartesian coordinates. The function may be called twice, once to retrieve the result columns (with null parameters), and the second time to return the data.

Parameters:

r - the distance from the point 0/0

alpha - the angle

Returns:

a result set with two columns: x and y

polar2CartesianArray

public static java.lang.Object[] polar2CartesianArray(java.lang.Double r,
                                                      java.lang.Double alpha)

Convert polar coordinates to cartesian coordinates. The function may be called twice, once to retrieve the result columns (with null parameters), and the second time to return the data.

Parameters:

r - the distance from the point 0/0

alpha - the angle

Returns:

an array two values: x and y

polar2CartesianSet

public static java.sql.ResultSet polar2CartesianSet(java.sql.Connection conn,
                                                    java.lang.String query)
                                             throws java.sql.SQLException

Convert a set of polar coordinates to cartesian coordinates. The function may be called twice, once to retrieve the result columns (with null parameters), and the second time to return the data.

Parameters:

conn - the connection

query - the query

Returns:

a result set with the coordinates

Throws:

java.sql.SQLException