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ASF GitHub Bot commented on FLINK-6925: --------------------------------------- Github user twalthr commented on a diff in the pull request: https://github.com/apache/flink/pull/4138#discussion_r123946426 --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala --- @@ -0,0 +1,79 @@ +/* + * 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 + +import scala.annotation.varargs +import java.math.{BigDecimal => JBigDecimal} +import java.lang.{StringBuffer => JStringBuffer} + +/** + * All build-in scalar scalar functions. + */ +class ScalarFunctions {} + +object ScalarFunctions { + + def power(a: Double, b: JBigDecimal): Double = { + Math.pow(a, b.doubleValue()) + } + + /** + * Returns the string that results from concatenating the arguments. + * Returns NULL if any argument is NULL. + */ + @varargs --- End diff -- This is a internal method. We don't need varargs here, we can use `Array[String]`. > Add CONCAT/CONCAT_WS supported in SQL > ------------------------------------- > > Key: FLINK-6925 > URL: https://issues.apache.org/jira/browse/FLINK-6925 > Project: Flink > Issue Type: Sub-task > Components: Table API & SQL > Affects Versions: 1.4.0 > Reporter: sunjincheng > Assignee: sunjincheng > > CONCAT(str1,str2,...)Returns the string that results from concatenating the > arguments. May have one or more arguments. If all arguments are nonbinary > strings, the result is a nonbinary string. If the arguments include any > binary strings, the result is a binary string. A numeric argument is > converted to its equivalent nonbinary string form. > CONCAT() returns NULL if any argument is NULL. > * Syntax: > CONCAT(str1,str2,...) > * Arguments > ** str1,str2,... - > * Return Types > string > * Example: > CONCAT('F', 'lin', 'k') -> 'Flink' > CONCAT('M', NULL, 'L') -> NULL > CONCAT(14.3) -> '14.3' > * See more: > ** [MySQL| > https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_concat] > CONCAT_WS() stands for Concatenate With Separator and is a special form of > CONCAT(). The first argument is the separator for the rest of the arguments. > The separator is added between the strings to be concatenated. The separator > can be a string, as can the rest of the arguments. If the separator is NULL, > the result is NULL. > * Syntax: > CONCAT_WS(separator,str1,str2,...) > * Arguments > ** separator - > ** str1,str2,... - > * Return Types > string > * Example: > CONCAT_WS(',','First name','Second name','Last Name') -> 'First name,Second > name,Last Name' > * See more: > ** [MySQL| > https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_concat-ws] -- This message was sent by Atlassian JIRA (v6.4.14#64029)