[
https://issues.apache.org/jira/browse/FLINK-6975?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16083649#comment-16083649
]
ASF GitHub Bot commented on FLINK-6975:
---------------------------------------
Github user wuchong commented on a diff in the pull request:
https://github.com/apache/flink/pull/4274#discussion_r126870614
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
---
@@ -982,4 +982,27 @@ object randInteger {
}
}
+/**
+ * Returns the string that results from concatenating the arguments.
+ * Returns NULL if any argument is NULL.
+ */
+object concat {
+ def apply(strings: Expression*): Expression = {
+ new Concat(strings)
+ }
+}
+
+/**
+ * Returns the string that results from concatenating the arguments and
separator.
+ * Returns NULL If the separator is NULL.
+ *
+ * Note: this user-defined function does not skip empty strings. However,
it does skip any NULL
+ * values after the separator argument.
+ **/
+object concat_ws {
+ def apply(separator: Expression, strings: Expression*): Expression = {
--- End diff --
I would suggest to change this signature to `apply(separator: Expression,
first: Expression, second: Expression, rest: Expression*)` to avoid misusage
such as `concat_ws(",")`.
> Add CONCAT/CONCAT_WS supported in TableAPI
> ------------------------------------------
>
> Key: FLINK-6975
> URL: https://issues.apache.org/jira/browse/FLINK-6975
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Affects Versions: 1.4.0
> Reporter: sunjincheng
> Assignee: sunjincheng
> Labels: starter
>
> See FLINK-6925 for detail.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
