maropu commented on a change in pull request #30816: URL: https://github.com/apache/spark/pull/30816#discussion_r545530056
########## File path: docs/sql-ref-syntax-qry-select-regex-column.md ########## @@ -0,0 +1,82 @@ +--- +layout: global +title: Regex Column Names +displayTitle: Regex Column Names +license: | + 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. +--- + +### Description + +When `spark.sql.parser.quotedRegexColumnNames` is true, quoted Identifiers (using backticks) in SELECT statement are interpreted as regular expressions and SELECT statement can take regex-based column specification. + +### Syntax + +```sql +SELECT `regex` FROM ... +``` + +### Parameters + +* **regex** + + Quoted Java regex syntax to represents all of the input attributes to a given relational operator. + +### Examples + +```sql +CREATE TABLE person (id INT, name STRING, age INT, class INT, address STRING); +INSERT INTO person VALUES + (100, 'John', 30, 1, 'Street 1'), + (200, 'Mary', NULL, 1, 'Street 2'), + (300, 'Mike', 80, 3, 'Street 3'), + (400, 'Dan', 50, 4, 'Street 4'); +SET spark.sql.parser.quotedRegexColumnNames=true; + +SELECT `(class|address)?+.+` FROM person; Review comment: We need a dedicated page for this functionality? How about adding some simple SELECT examples in the top SELECT page? IMHO its okay to add them in https://spark.apache.org/docs/latest/sql-ref-syntax-qry-select.html cc: @HyukjinKwon @gatorsmile ---------------------------------------------------------------- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
