cloud-fan commented on a change in pull request #27897: [SPARK-31113][SQL] Add SHOW VIEWS command URL: https://github.com/apache/spark/pull/27897#discussion_r400919260
########## File path: docs/sql-ref-syntax-aux-show-views.md ########## @@ -0,0 +1,120 @@ +--- +layout: global +title: SHOW VIEWS +displayTitle: SHOW VIEWS +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 + +The `SHOW VIEWS` statement returns all the views for an optionally specified database. +Additionally, the output of this statement may be filtered by an optional matching +pattern. If no database is specified then the views are returned from the +current database. Note that the command also lists local temporary views +regardless of a given database. + +### Syntax +{% highlight sql %} +SHOW VIEWS [ { FROM | IN } database_name ] [ LIKE 'regex_pattern' ] +{% endhighlight %} + +### Parameters +<dl> + <dt><code><em>{ FROM | IN } database_name</em></code></dt> + <dd> + Specifies the database name from which views are listed. + </dd> + <dt><code><em>LIKE regex_pattern</em></code></dt> + <dd> + Specifies the regular expression pattern that is used to filter out unwanted views. + <ul> + <li> Except for `*` and `|` character, the pattern works like a regex.</li> + <li> `*` alone matches 0 or more characters and `|` is used to separate multiple different regexes, + any of which can match. </li> + <li> The leading and trailing blanks are trimmed in the input pattern before processing.</li> + </ul> + </dd> +</dl> + +### Example +{% highlight sql %} +-- Create views in different databases, also create global/local temp views. +CREATE VIEW sam AS SELECT id, salary FROM employee WHERE name = 'sam'; +CREATE VIEW sam1 AS SELECT id, salary FROM employee WHERE name = 'sam1'; +CREATE VIEW suj AS SELECT id, salary FROM employee WHERE name = 'suj'; +USE userdb; +CREATE VIEW user1 AS SELECT id, salary FROM employee WHERE name = 'user1'; +CREATE VIEW user2 AS SELECT id, salary FROM employee WHERE name = 'user2'; +USE default; +CREATE GLOBAL TEMP VIEW temp1 AS SELECT 1 as col1; +CREATE TEMP VIEW temp2 AS SELECT 1 as col1; + +-- List all views in default database +SHOW VIEWS; + +-------------+------------+--------------+--+ + | namespace | viewName | isTemporary | + +-------------+------------+--------------+--+ + | default | sam | false | + | default | sam1 | false | + | default | suj | false | + | | temp2 | true | + +-------------+------------+--------------+--+ + +-- List all views from userdb database +SHOW VIEWS FROM userdb; + +-------------+------------+--------------+--+ + | namespace | viewName | isTemporary | + +-------------+------------+--------------+--+ + | userdb | user1 | false | + | userdb | user2 | false | + | | temp2 | true | + +-------------+------------+--------------+--+ + +-- List all views in global temp view database +SHOW VIEWS IN global_temp; + +-------------+------------+--------------+--+ + | namespace | viewName | isTemporary | + +-------------+------------+--------------+--+ + | global_temp | temp1 | true | + | | temp2 | true | + +-------------+------------+--------------+--+ + +-- List all views from default database matching the pattern `sam*` +SHOW VIEWS FROM default LIKE 'sam*'; + +-----------+------------+--------------+--+ + | namespace | viewName | isTemporary | + +-----------+------------+--------------+--+ + | default | sam | false | + | default | sam1 | false | + +-----------+------------+--------------+--+ + +-- List all views matching the pattern `sam|suj｜temp*` Review comment: `List all views from the current database` ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
