/*
* 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 net.hydromatic.optiq.model;
/**
* An aggregate function applied to a column (or columns) of a lattice.
*
* <p>Occurs in a {@link net.hydromatic.optiq.model.JsonTile},
* and there is a default list in
* {@link net.hydromatic.optiq.model.JsonLattice}.
*
* @see JsonRoot Description of schema elements
*/
public class JsonMeasure {
public String agg;
/** Arguments to the measure.
*
* <p>Valid values are:
* <ul>
* <li>Not specified: no arguments</li>
* <li>null: no arguments</li>
* <li>Empty list: no arguments</li>
* <li>String: single argument, the name of a lattice column</li>
* <li>List: multiple arguments, each a column name</li>
* </ul>
*
* <p>Unlike lattice dimensions, measures can not be specified in qualified
* format, {@code ["table", "column"]}. When you define a lattice, make sure
* that each column you intend to use as a measure has a unique name within
* the lattice (using "{@code AS alias}" if necessary).
*/
public Object args;
public void accept(ModelHandler modelHandler) {
modelHandler.visit(this);
}
}
// End JsonMeasure.java