jsqlite.Function Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of spatialite-android Show documentation

Vector map library written in Java - running on Android and Desktop.

The newest version!

package jsqlite;

/**
 * Callback interface for SQLite's user defined functions.
 * Each callback method receives a
 * FunctionContext object
 * which is used to set the function result or error code.
 * 


 * Example:

 * 
 * 
 * class SinFunc implements SQLite.Function {
 * public void function(SQLite.FunctionContext fc, String args[]) {
 * try {
 * Double d = new Double(args[0]);
 * fc.set_result(Math.sin(d.doubleValue()));
 * } catch (Exception e) {
 * fc.set_error("sin(" + args[0] + "):" + e);
 * }
 * }
 * ...
 * }
 * SQLite.Database db = new SQLite.Database();
 * db.open("db", 0);
 * db.create_function("sin", 1, SinFunc);
 * ...
 * db.exec("select sin(1.0) from test", null);
 * 
 */

public interface Function {

    /**
     * Callback for regular function.
     *
     * @param fc   function's context for reporting result
     * @param args String array of arguments
     */

    public void function(FunctionContext fc, String args[]);

    /**
     * Callback for one step in aggregate function.
     *
     * @param fc   function's context for reporting result
     * @param args String array of arguments
     */

    public void step(FunctionContext fc, String args[]);

    /**
     * Callback for final step in aggregate function.
     *
     * @param fc function's context for reporting result
     */

    public void last_step(FunctionContext fc);

}