yiyutian1 commented on code in PR #25763: URL: https://github.com/apache/flink/pull/25763#discussion_r1894146265
########## flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/runtime/functions/scalar/ToTimestampLtzFunction.java: ########## @@ -0,0 +1,139 @@ +/* + * 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.runtime.functions.scalar; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.data.DecimalData; +import org.apache.flink.table.data.StringData; +import org.apache.flink.table.data.TimestampData; +import org.apache.flink.table.functions.BuiltInFunctionDefinitions; +import org.apache.flink.table.functions.SpecializedFunction; +import org.apache.flink.table.utils.DateTimeUtils; + +import javax.annotation.Nullable; + +import java.time.DateTimeException; +import java.time.ZoneId; +import java.time.ZonedDateTime; + +import static org.apache.flink.table.utils.DateTimeUtils.parseTimestampData; + +/** + * Implementation of {@link BuiltInFunctionDefinitions#TO_TIMESTAMP_LTZ}. + * + * <p>A function that converts various time formats to TIMESTAMP_LTZ type. + * + * <p>Supported function signatures: + * + * <ul> + * <li>{@code TO_TIMESTAMP_LTZ(numeric)} -> TIMESTAMP_LTZ(3) <br> + * Converts numeric epoch time in milliseconds to timestamp with local timezone + * <li>{@code TO_TIMESTAMP_LTZ(numeric, precision)} -> TIMESTAMP_LTZ(precision) <br> + * Converts numeric epoch time to timestamp with specified precision (0 as seconds, 3 as + * milliseconds) + * <li>{@code TO_TIMESTAMP_LTZ(timestamp)} -> TIMESTAMP_LTZ(3) <br> + * Parses string timestamp using default format 'yyyy-MM-dd HH:mm:ss' + * <li>{@code TO_TIMESTAMP_LTZ(timestamp, format)} -> TIMESTAMP_LTZ(3) <br> + * Parses string timestamp using input string of format + * <li>{@code TO_TIMESTAMP_LTZ(timestamp, format, timezone)} -> TIMESTAMP_LTZ(3) <br> + * Parses string timestamp using input strings of format and timezone + * </ul> + * + * <p>Example: + * + * <pre>{@code + * TO_TIMESTAMP_LTZ('2023-01-01 10:00:00') // Parses string using default format + * TO_TIMESTAMP_LTZ(1234567890123) // Converts epoch milliseconds + * TO_TIMESTAMP_LTZ(1234567890, 0) // Converts epoch seconds + * TO_TIMESTAMP_LTZ(1234567890123, 3) // Converts epoch milliseconds + * TO_TIMESTAMP_LTZ('2023-01-01 10:00:00') // Parses string using default format + * TO_TIMESTAMP_LTZ('2023-01-01T10:00:00', 'yyyy-MM-dd\'T\'HH:mm:ss') // Parses string using input format + * TO_TIMESTAMP_LTZ('2023-01-01 10:00:00', 'yyyy-MM-dd HH:mm:ss', 'UTC') // Parses string using input format and timezone + * }</pre> + */ +@Internal +public class ToTimestampLtzFunction extends BuiltInScalarFunction { + + private static final int DEFAULT_PRECISION = 3; + + public ToTimestampLtzFunction(SpecializedFunction.SpecializedContext context) { + super(BuiltInFunctionDefinitions.TO_TIMESTAMP_LTZ, context); + } + + public @Nullable TimestampData eval(Number epoch, Integer precision) { + if (epoch == null || precision == null) { + return null; + } + if (epoch instanceof Float || epoch instanceof Double) { + return DateTimeUtils.toTimestampData(epoch.doubleValue(), precision); + } + return DateTimeUtils.toTimestampData(epoch.longValue(), precision); + } + + public @Nullable TimestampData eval(DecimalData epoch, Integer precision) { + if (epoch == null || precision == null) { + return null; + } + + return DateTimeUtils.toTimestampData(epoch, precision); + } + + public @Nullable TimestampData eval(Number epoch) { + return eval(epoch, DEFAULT_PRECISION); + } + + public @Nullable TimestampData eval(DecimalData epoch) { + return eval(epoch, DEFAULT_PRECISION); + } + + public @Nullable TimestampData eval(StringData timestamp) { + if (timestamp == null) { + return null; + } + + return parseTimestampData(timestamp.toString()); + } + + public @Nullable TimestampData eval(StringData timestamp, StringData format) { + if (timestamp == null || format == null) { + return null; + } + + return parseTimestampData(timestamp.toString(), format.toString()); + } + + public @Nullable TimestampData eval( + StringData dateStr, StringData format, StringData timezone) { + if (dateStr == null || format == null || timezone == null) { + return null; + } + + TimestampData ts = parseTimestampData(dateStr.toString(), format.toString()); + if (ts == null) { + return null; + } + + try { + ZonedDateTime zoneDate = ts.toLocalDateTime().atZone(ZoneId.of(timezone.toString())); + return TimestampData.fromInstant(zoneDate.toInstant()); + } catch (DateTimeException e) { + return null; + } + } Review Comment: Hi @snuyanzin , thank you for clarifying! After another look, that method in `DateTimeUtils.java` is not the same as the one I have here. I need `parseTimestampData(dateStr, format, timezone);` But that method in DateTimeUtils.java is: `parseTimestampData(dateStr, precision, timeZone)` So the only difference is where I want to put this method. I have this function within `ToTimestampLtzFunction.java` because it handles invalid cases in a particular way. When we have invalid **timestamp** and **format** and **zoneID**, here we want to return NULL. I can also put it in DateTimeUtils.java, should other functions need it, but now `ToTimestampLtzFunction.java` is the only function that uses it. Unless there is a particular benefit in adding another method to `DateTimeUtils.java `, I think it's OK to have this method with particular behavior in `ToTimestampLtzFunction.java`. What do you think? -- This is an automated message from the Apache Git Service. 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