org.apache.calcite.model.JsonMeasure Maven / Gradle / Ivy
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/*
* 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.calcite.model;
/**
* An aggregate function applied to a column (or columns) of a lattice.
*
* Occurs in a {@link org.apache.calcite.model.JsonTile},
* and there is a default list in
* {@link org.apache.calcite.model.JsonLattice}.
*
* @see JsonRoot Description of schema elements
*/
public class JsonMeasure {
/** The name of an aggregate function.
*
*
Required. Usually {@code count}, {@code sum},
* {@code min}, {@code max}.
*/
public String agg;
/** Arguments to the measure.
*
*
Valid values are:
*
* - Not specified: no arguments
* - null: no arguments
* - Empty list: no arguments
* - String: single argument, the name of a lattice column
* - List: multiple arguments, each a column name
*
*
* 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