io.druid.sql.calcite.expression.SqlExtractionOperator Maven / Gradle / Ivy
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* Licensed to Metamarkets Group Inc. (Metamarkets) under one
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* distributed with this work for additional information
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* 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
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*/
package io.druid.sql.calcite.expression;
import io.druid.sql.calcite.planner.PlannerContext;
import org.apache.calcite.rex.RexNode;
import org.apache.calcite.sql.SqlFunction;
import java.util.List;
public interface SqlExtractionOperator
{
/**
* Returns the SQL operator corresponding to this aggregation function. Should be a singleton.
*
* @return operator
*/
SqlFunction calciteFunction();
/**
* Returns the Druid {@link RowExtraction} corresponding to a SQL {@code RexNode}.
*
* @param plannerContext SQL planner context
* @param rowOrder order of fields in the Druid rows to be extracted from
* @param expression expression meant to be applied on top of the table
*
* @return (columnName, extractionFn) or null
*
* @see Expressions#toRowExtraction(PlannerContext, List, RexNode)
*/
RowExtraction convert(
PlannerContext plannerContext,
List rowOrder,
RexNode expression
);
}