Query.java

/***************************************************************************
   Copyright 2012 Emily Estes

   Licensed 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 net.metanotion.sqlc;


import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import net.metanotion.sqlc.setters.SQLSetter;

/** This expression directly executes a SQL query that returns a result set. */
public final class Query implements QueryExpr<ResultSet> {
	private static final Logger logger = LoggerFactory.getLogger(Query.class);

	public final String sql;
	public final List<SQLSetter> setters;
	/** Create a new query evaluator that transforms it's parameters from the environment with the provided setters.
		@param sql The sql query to evaluate.
		@param setters The list of setters to populate the parameters of the query.
	*/
	public Query(final String sql, final List<SQLSetter> setters) {
		this.sql = sql;
		this.setters = setters;
	}

	@Override public ResultSet eval(final Connection conn, final Map<String,Object> env) throws SQLException {
		final PreparedStatement stmt = conn.prepareStatement(sql);
		logger.debug(sql);
		for(final SQLSetter s: setters) { s.set(stmt, env); }
		return stmt.executeQuery();
	}
}