godfreyhe commented on a change in pull request #8157: [FLINK-12170] [table-planner-blink] Add support for generating optimized logical plan for Over aggregate URL: https://github.com/apache/flink/pull/8157#discussion_r275291974
########## File path: flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/functions/aggfunctions/RankLikeAggFunctionBase.java ########## @@ -0,0 +1,128 @@ +/* + * 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.flink.table.functions.aggfunctions; + +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.api.common.typeinfo.Types; +import org.apache.flink.table.api.TableException; +import org.apache.flink.table.expressions.Expression; +import org.apache.flink.table.expressions.UnresolvedReferenceExpression; +import org.apache.flink.table.type.DecimalType; +import org.apache.flink.table.type.InternalType; +import org.apache.flink.table.type.InternalTypes; + +import java.sql.Date; +import java.sql.Time; +import java.sql.Timestamp; + +import static org.apache.flink.table.expressions.ExpressionBuilder.and; +import static org.apache.flink.table.expressions.ExpressionBuilder.equalTo; +import static org.apache.flink.table.expressions.ExpressionBuilder.ifThenElse; +import static org.apache.flink.table.expressions.ExpressionBuilder.isNull; +import static org.apache.flink.table.expressions.ExpressionBuilder.literal; + +/** + * built-in rank like aggregate function, e.g. rank, dense_rank + */ +public abstract class RankLikeAggFunctionBase extends DeclarativeAggregateFunction { + protected UnresolvedReferenceExpression sequence = new UnresolvedReferenceExpression("sequence"); + protected UnresolvedReferenceExpression[] lastValues; + protected InternalType[] orderKeyTypes; + + public RankLikeAggFunctionBase(InternalType[] orderKeyTypes) { + this.orderKeyTypes = orderKeyTypes; + lastValues = new UnresolvedReferenceExpression[orderKeyTypes.length]; + for (int i = 0; i < orderKeyTypes.length; ++i) { + lastValues[i] = new UnresolvedReferenceExpression("lastValue_" + i); + } + } + + @Override + public int operandCount() { + return orderKeyTypes.length; + } + + @Override + public TypeInformation getResultType() { + return Types.LONG; + } + + @Override + public Expression[] retractExpressions() { + throw new TableException("This function does not support retraction."); + } + + @Override + public Expression[] mergeExpressions() { + throw new TableException("This function does not support merge."); + } + + @Override + public Expression getValueExpression() { + return sequence; + } + + protected Expression orderKeyEqualsExpression() { + Expression[] orderKeyEquals = new Expression[orderKeyTypes.length]; + for (int i = 0; i < orderKeyTypes.length; ++i) { + Expression lasValue = lastValues[i]; + // if (lastValue is null) { Review comment: These are comments, just look like code. I have deleted them. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
