Package org.h2.samples

Class FunctionMultiReturn

java.lang.Object
org.h2.samples.FunctionMultiReturn
public class FunctionMultiReturn extends 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 Details

    • FunctionMultiReturn

      public FunctionMultiReturn()

  • Method Details

    • main

      public static void main(String... args) throws Exception
      This method is called when executing this sample application from the command line.
      Parameters:
      args - the command line parameters
      Throws:
      Exception - on failure

    • polar2Cartesian

      public static ResultSet polar2Cartesian(Double r, 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 Double[] polar2CartesianArray(Double r, 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 ResultSet polar2CartesianSet(Connection conn, String query) throws 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:
      SQLException - on failure