edu.jhu.tmaj.database
Class DatabaseQuery

java.lang.Object
  edu.jhu.tmaj.database.DatabaseQuery

public abstract class DatabaseQuery
extends java.lang.Object

A class for executing SELECT statement. Implementors must overwrite handleResultSet() thus handling each row returned by the query properly. This class takes care of the overhead of executing a sql statement such as getting a connection and returning it.
Example:
This code is used to populate a List with all the names of all the Projects.
(Assume the name of the Project is stored in a field called "ProjectName" in the "Projects" table.)
final List projectNamesList=new ArrayList();
AbstractDatabaseQuery d = new AbstractDatabaseQuery("SELECT ProjectName FROM Projects", sqlMaker, cm, logger){
protected void handleResultSet(ResultSet rs) throws SQLException{
String projectName = rs.getString("ProjectName");
projectNamesList.add(projectName);
}
};
d.execute();
System.out.println("The names of the projects: " + d.projectNamesList);


Constructor Summary

	DatabaseQuery(java.lang.String sql)
protected	DatabaseQuery(java.lang.String sql, DatabaseLink databaseLink) Creates this object.

Method Summary

void	execute()
protected abstract void	handleResultSet(java.sql.ResultSet rs) Called for every row the SELECT statement generates.

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseQuery

protected DatabaseQuery(java.lang.String sql,
                        DatabaseLink databaseLink)

Creates this object.

Parameters:

sql - the SQL statement this class will execute.

DatabaseQuery

public DatabaseQuery(java.lang.String sql)

Method Detail

execute

public final void execute()
                   throws java.sql.SQLException

Throws:

java.sql.SQLException

handleResultSet

protected abstract void handleResultSet(java.sql.ResultSet rs)
                                 throws java.sql.SQLException

Called for every row the SELECT statement generates. Subclasses overwrite this class and handle the data from the ResultSet appropriately.

Throws:

java.sql.SQLException