org.grouplens.lenskit.data.sql

Interface SQLStatementFactory

All Known Implementing Classes:

BasicSQLStatementFactory

@Immutable
public interface SQLStatementFactory

Interface for producing sql strings rating DAO queries.

The JDBC DAO framework operates by expecting a statement factory to construct queries which return results in a defined format.

Method Summary

Modifier and Type	Method and Description
String	prepareEvents(SortOrder order) Prepare a statement to satisfy EventDAO.streamEvents(Class, SortOrder).
String	prepareItemEvents() Prepare a statement to satisfy ItemEventDAO.getEventsForItem(long).
String	prepareItems() Prepare a statement to satisfy ItemDAO.getItemIds().
String	prepareItemUsers() Prepare a statement to satisfy ItemEventDAO.getUsersForItem(long).
String	prepareUserEvents() Prepare a statement to satisfy UserEventDAO.getEventsForUser(long).
String	prepareUsers() Prepare a statement to satisfy UserDAO.getUserIds().

Method Detail

prepareUsers

String prepareUsers()

Prepare a statement to satisfy UserDAO.getUserIds(). Querying the statement should return one column per row containing the numeric user ID.

Returns:

A string for a sql query containing user ID data.

prepareItems

String prepareItems()

Prepare a statement to satisfy ItemDAO.getItemIds(). Querying the statement should return one column per row containing the numeric item ID.

Returns:

A string for a sql query containing item ID data.

prepareEvents

String prepareEvents(SortOrder order)

Prepare a statement to satisfy EventDAO.streamEvents(Class, SortOrder). Each row should contain three or four columns: the user ID, the item ID, the rating, and (optionally) the timestamp. The timestamp column is allowed to contain NULL values or to be omitted entirely. User, item, and rating columns must be non-null.

Parameters:

order - The sort order

prepareUserEvents

String prepareUserEvents()

Prepare a statement to satisfy UserEventDAO.getEventsForUser(long). The returned rows should be as in prepareEvents(SortOrder), and the prepared statement should take a single parameter for the user ID.

Returns:

A string for a sql query returning user rating data. The ratings must be in timestamp order.

prepareItemEvents

String prepareItemEvents()

Prepare a statement to satisfy ItemEventDAO.getEventsForItem(long). The returned rows should be as in prepareEvents(SortOrder), and the prepared statement should take a single parameter for the item ID.

Returns:

A string for a sql query returning item rating data. The ratings must be ordered first by user ID, then by timestamp.

prepareItemUsers

String prepareItemUsers()

Prepare a statement to satisfy ItemEventDAO.getUsersForItem(long). The returned rows should each contain a user ID as their only column, and the statement should take a single parameter for the item ID.

Returns:

A string for a sql query returning item rating data. The ratings must be ordered first by user ID, then by timestamp.