org.h2.samples
Class FunctionMultiReturn

java.lang.Object
  extended by 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
FunctionMultiReturn()
           
 
Method Summary
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