snuyanzin commented on code in PR #26704: URL: https://github.com/apache/flink/pull/26704#discussion_r2157628363
########## flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/inference/strategies/ObjectOfInputTypeStrategy.java: ########## @@ -0,0 +1,162 @@ +/* + * 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.types.inference.strategies; + +import org.apache.flink.table.api.ValidationException; +import org.apache.flink.table.functions.FunctionDefinition; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.inference.ArgumentCount; +import org.apache.flink.table.types.inference.CallContext; +import org.apache.flink.table.types.inference.InputTypeStrategy; +import org.apache.flink.table.types.inference.Signature; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeFamily; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Optional; +import java.util.Set; + +/** + * Input type strategy for the {@code OBJECT_OF} function that validates argument types and counts. + * + * <p>This strategy validates the input arguments for the {@code OBJECT_OF} function, ensuring: + * + * <ul> + * <li>The argument count is odd (className + pairs of key-value arguments) + * <li>The first argument is a STRING/VARCHAR representing the class name + * <li>All key arguments (odd positions after the first) are STRING/VARCHAR types + * <li>Field names are unique across all key-value pairs + * <li>Value arguments (even positions after the first) can be any type + * </ul> + * + * <p>The expected function signature is: {@code OBJECT_OF(className, key1, value1, key2, value2, + * ...)} + * + * <p>Validation rules: + * + * <ul> + * <li>Minimum 1 argument (just the class name) + * <li>Odd total number of arguments (className + key-value pairs) + * <li>Keys must be string literals for field name extraction + * <li>No duplicate field names allowed + * </ul> + * + * <p>Example valid calls: + * + * <ul> + * <li>{@code OBJECT_OF('com.example.User')} - empty object + * <li>{@code OBJECT_OF('com.example.User', 'name', 'Alice')} - single field + * <li>{@code OBJECT_OF('com.example.User', 'name', 'Alice', 'age', 30)} - multiple fields + * </ul> + * + * @see org.apache.flink.table.functions.BuiltInFunctionDefinitions#OBJECT_OF + * @see ObjectOfTypeStrategy + */ +public class ObjectOfInputTypeStrategy implements InputTypeStrategy { + + private static final ArgumentCount AT_LEAST_ONE_ODD = + new ArgumentCount() { + @Override + public boolean isValidCount(int count) { + return count % 2 == 1; + } + + @Override + public Optional<Integer> getMinCount() { + return Optional.of(1); + } + + @Override + public Optional<Integer> getMaxCount() { + return Optional.empty(); + } + }; + + private static void validateFieldName( + final CallContext callContext, + final int idx, + final LogicalType logicalType, + final Set<String> filedNames) { + final int keyIndex = (idx + 1); + if (!logicalType.is(LogicalTypeFamily.CHARACTER_STRING)) { + throw new ValidationException( + "The field key at position " + + keyIndex + + " must be a STRING/VARCHAR type, but was " + + logicalType.asSummaryString() + + "."); + } Review Comment: should we check if it is not null (or not nullable)? Otherwise output for nullable classname is confusing like ```sql SELECT OBJECT_OF(cast(null as string), 'f0', 'a', 'b', 'Alice'); ``` gives ``` Caused by: org.apache.flink.table.api.ValidationException: Invalid function call: OBJECT_OF(STRING, CHAR(2) NOT NULL, CHAR(1) NOT NULL, CHAR(1) NOT NULL, CHAR(5) NOT NULL) ... Caused by: org.apache.flink.table.api.ValidationException: Could not infer an output type for the given arguments. ``` which in fact satisfies the required ``` Supported signatures are: OBJECT_OF(STRING, [STRING, ANY]*...) ``` -- 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. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
