/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.cf.taste.impl.model.jdbc;
import com.google.common.base.Preconditions;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.common.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
/**
* <p>
* A {@link org.apache.mahout.cf.taste.model.JDBCDataModel} backed by a PostgreSQL database and
* accessed via JDBC. It may work with other JDBC databases. By default, this class
* assumes that there is a {@link javax.sql.DataSource} available under the JNDI name
* "jdbc/taste", which gives access to a database with a "taste_preferences" table with the following schema:
* </p>
*
* <p>
*
* <pre>
* CREATE TABLE taste_preferences (
* user_id BIGINT NOT NULL,
* item_id BIGINT NOT NULL,
* preference REAL NOT NULL,
* PRIMARY KEY (user_id, item_id)
* )
* CREATE INDEX taste_preferences_user_id_index ON taste_preferences (user_id);
* CREATE INDEX taste_preferences_item_id_index ON taste_preferences (item_id);
* </pre>
*
* </p>
*
* @see PostgreSQLJDBCDataModel
*/
public class PostgreSQLJDBCDataModel extends SQL92JDBCDataModel {
private static final Logger log = LoggerFactory.getLogger(PostgreSQLJDBCDataModel.class);
private static final String POSTGRESQL_DUPLICATE_KEY_STATE = "23505"; // this is brittle...
/**
* <p>
* Creates a using the default {@link javax.sql.DataSource} (named
* {@link #DEFAULT_DATASOURCE_NAME} and default table/column names.
* </p>
*
* @throws org.apache.mahout.cf.taste.common.TasteException
* if {@link javax.sql.DataSource} can't be found
*/
public PostgreSQLJDBCDataModel() throws TasteException {
}
/**
* <p>
* Creates a using the default {@link javax.sql.DataSource} found under the given name, and
* using default table/column names.
* </p>
*
* @param dataSourceName name of {@link javax.sql.DataSource} to look up
* @throws org.apache.mahout.cf.taste.common.TasteException
* if {@link javax.sql.DataSource} can't be found
*/
public PostgreSQLJDBCDataModel(String dataSourceName) throws TasteException {
super(dataSourceName);
}
/**
* <p>
* Creates a using the given {@link javax.sql.DataSource} and default table/column names.
* </p>
*
* @param dataSource {@link javax.sql.DataSource} to use
*/
public PostgreSQLJDBCDataModel(DataSource dataSource) {
super(dataSource);
}
/**
* <p>
* Creates a using the given {@link javax.sql.DataSource} and default table/column names.
* </p>
*
* @param dataSource {@link javax.sql.DataSource} to use
* @param preferenceTable name of table containing preference data
* @param userIDColumn user ID column name
* @param itemIDColumn item ID column name
* @param preferenceColumn preference column name
* @param timestampColumn timestamp column name (may be null)
*/
public PostgreSQLJDBCDataModel(DataSource dataSource,
String preferenceTable,
String userIDColumn,
String itemIDColumn,
String preferenceColumn,
String timestampColumn) {
super(dataSource, preferenceTable, userIDColumn, itemIDColumn, preferenceColumn, timestampColumn);
}
/**
* Override since PostgreSQL doesn't have the same non-standard capability that MySQL has, to optionally
* insert or update in one statement.
*/
@Override
public void setPreference(long userID, long itemID, float value) throws TasteException {
Preconditions.checkArgument(!Float.isNaN(value), "NaN value");
log.debug("Setting preference for user {}, item {}", userID, itemID);
String setPreferenceSQL = getSetPreferenceSQL();
Connection conn = null;
PreparedStatement stmt1 = null;
PreparedStatement stmt2 = null;
try {
conn = getDataSource().getConnection();
stmt1 = conn.prepareStatement(setPreferenceSQL);
setLongParameter(stmt1, 1, userID);
setLongParameter(stmt1, 2, itemID);
stmt1.setDouble(3, value);
log.debug("Executing SQL update: {}", setPreferenceSQL);
try {
stmt1.executeUpdate();
} catch (SQLException sqle) {
if (!POSTGRESQL_DUPLICATE_KEY_STATE.equals(sqle.getSQLState())) {
throw sqle;
}
}
// Continue with update; just found the key already exists
stmt2 = conn.prepareStatement(getUpdatePreferenceSQL());
stmt2.setDouble(1, value);
setLongParameter(stmt2, 2, userID);
setLongParameter(stmt2, 3, itemID);
log.debug("Executing SQL update: {}", getUpdatePreferenceSQL());
stmt2.executeUpdate();
} catch (SQLException sqle) {
log.warn("Exception while setting preference", sqle);
throw new TasteException(sqle);
} finally {
IOUtils.quietClose(null, stmt1, null);
IOUtils.quietClose(null, stmt2, null);
IOUtils.quietClose(null, null, conn);
}
}
}