2020-04-07 12:25:01 -04:00
|
|
|
|
---
|
|
|
|
|
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.
|
|
|
|
|
---
|
[SPARK-31383][SQL][DOC] Clean up the SQL documents in docs/sql-ref*
### What changes were proposed in this pull request?
This PR intends to clean up the SQL documents in `doc/sql-ref*`.
Main changes are as follows;
- Fixes wrong syntaxes and capitalize sub-titles
- Adds some DDL queries in `Examples` so that users can run examples there
- Makes query output in `Examples` follows the `Dataset.showString` (right-aligned) format
- Adds/Removes spaces, Indents, or blank lines to follow the format below;
```
---
license...
---
### Description
Writes what's the syntax is.
### Syntax
{% highlight sql %}
SELECT...
WHERE... // 4 indents after the second line
...
{% endhighlight %}
### Parameters
<dl>
<dt><code><em>Param Name</em></code></dt>
<dd>
Param Description
</dd>
...
</dl>
### Examples
{% highlight sql %}
-- It is better that users are able to execute example queries here.
-- So, we prepare test data in the first section if possible.
CREATE TABLE t (key STRING, value DOUBLE);
INSERT INTO t VALUES
('a', 1.0), ('a', 2.0), ('b', 3.0), ('c', 4.0);
-- query output has 2 indents and it follows the `Dataset.showString`
-- format (right-aligned).
SELECT * FROM t;
+---+-----+
|key|value|
+---+-----+
| a| 1.0|
| a| 2.0|
| b| 3.0|
| c| 4.0|
+---+-----+
-- Query statements after the second line have 4 indents.
SELECT key, SUM(value)
FROM t
GROUP BY key;
+---+----------+
|key|sum(value)|
+---+----------+
| c| 4.0|
| b| 3.0|
| a| 3.0|
+---+----------+
...
{% endhighlight %}
### Related Statements
* [XXX](xxx.html)
* ...
```
### Why are the changes needed?
The most changes of this PR are pretty minor, but I think the consistent formats/rules to write documents are important for long-term maintenance in our community
### Does this PR introduce any user-facing change?
Yes.
### How was this patch tested?
Manually checked.
Closes #28151 from maropu/MakeRightAligned.
Authored-by: Takeshi Yamamuro <yamamuro@apache.org>
Signed-off-by: Sean Owen <srowen@gmail.com>
2020-04-13 00:40:36 -04:00
|
|
|
|
|
2020-04-07 12:25:01 -04:00
|
|
|
|
### 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. If the specified database is global temporary view database, we will
|
|
|
|
|
list global temporary views. Note that the command also lists local temporary views
|
|
|
|
|
regardless of a given database.
|
|
|
|
|
|
|
|
|
|
### Syntax
|
|
|
|
|
{% highlight sql %}
|
2020-04-28 20:17:23 -04:00
|
|
|
|
SHOW VIEWS [ { FROM | IN } database_name ] [ LIKE regex_pattern ]
|
2020-04-07 12:25:01 -04:00
|
|
|
|
{% endhighlight %}
|
|
|
|
|
|
|
|
|
|
### Parameters
|
|
|
|
|
<dl>
|
|
|
|
|
<dt><code><em>{ FROM | IN } database_name</em></code></dt>
|
|
|
|
|
<dd>
|
|
|
|
|
Specifies the database name from which views are listed.
|
|
|
|
|
</dd>
|
2020-04-28 20:17:23 -04:00
|
|
|
|
<dt><code><em>regex_pattern</em></code></dt>
|
2020-04-07 12:25:01 -04:00
|
|
|
|
<dd>
|
2020-04-28 20:17:23 -04:00
|
|
|
|
Specifies the regular expression pattern that is used to filter out unwanted views.
|
2020-04-07 12:25:01 -04:00
|
|
|
|
<ul>
|
2020-04-28 20:17:23 -04:00
|
|
|
|
<li>Except for <code>*</code> and <code>|</code> character, the pattern works like a regular expression.</li>
|
|
|
|
|
<li><code>*</code> alone matches 0 or more characters and <code>|</code> is used to separate multiple different regular expressions,
|
2020-04-07 12:25:01 -04:00
|
|
|
|
any of which can match. </li>
|
2020-04-28 20:17:23 -04:00
|
|
|
|
<li>The leading and trailing blanks are trimmed in the input pattern before processing. The pattern match is case-insensitive.</li>
|
2020-04-07 12:25:01 -04:00
|
|
|
|
</ul>
|
|
|
|
|
</dd>
|
|
|
|
|
</dl>
|
|
|
|
|
|
2020-04-30 17:30:35 -04:00
|
|
|
|
### Examples
|
2020-04-07 12:25:01 -04:00
|
|
|
|
{% 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 default.employee WHERE name = 'user1';
|
|
|
|
|
CREATE VIEW user2 AS SELECT id, salary FROM default.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;
|
2020-05-01 13:11:43 -04:00
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| namespace | viewName | isTemporary |
|
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| default | sam | false |
|
|
|
|
|
| default | sam1 | false |
|
|
|
|
|
| default | suj | false |
|
|
|
|
|
| | temp2 | true |
|
|
|
|
|
+-------------+------------+--------------+
|
2020-04-07 12:25:01 -04:00
|
|
|
|
|
|
|
|
|
-- List all views from userdb database
|
|
|
|
|
SHOW VIEWS FROM userdb;
|
2020-05-01 13:11:43 -04:00
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| namespace | viewName | isTemporary |
|
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| userdb | user1 | false |
|
|
|
|
|
| userdb | user2 | false |
|
|
|
|
|
| | temp2 | true |
|
|
|
|
|
+-------------+------------+--------------+
|
2020-04-07 12:25:01 -04:00
|
|
|
|
|
|
|
|
|
-- List all views in global temp view database
|
|
|
|
|
SHOW VIEWS IN global_temp;
|
2020-05-01 13:11:43 -04:00
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| namespace | viewName | isTemporary |
|
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| global_temp | temp1 | true |
|
|
|
|
|
| | temp2 | true |
|
|
|
|
|
+-------------+------------+--------------+
|
2020-04-07 12:25:01 -04:00
|
|
|
|
|
|
|
|
|
-- List all views from default database matching the pattern `sam*`
|
|
|
|
|
SHOW VIEWS FROM default LIKE 'sam*';
|
2020-05-01 13:11:43 -04:00
|
|
|
|
+-----------+------------+--------------+
|
|
|
|
|
| namespace | viewName | isTemporary |
|
|
|
|
|
+-----------+------------+--------------+
|
|
|
|
|
| default | sam | false |
|
|
|
|
|
| default | sam1 | false |
|
|
|
|
|
+-----------+------------+--------------+
|
2020-04-07 12:25:01 -04:00
|
|
|
|
|
|
|
|
|
-- List all views from the current database matching the pattern `sam|suj|temp*`
|
|
|
|
|
SHOW VIEWS LIKE 'sam|suj|temp*';
|
2020-05-01 13:11:43 -04:00
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| namespace | viewName | isTemporary |
|
|
|
|
|
+-------------+------------+--------------+
|
|
|
|
|
| default | sam | false |
|
|
|
|
|
| default | suj | false |
|
|
|
|
|
| | temp2 | true |
|
|
|
|
|
+-------------+------------+--------------+
|
2020-04-07 12:25:01 -04:00
|
|
|
|
|
|
|
|
|
{% endhighlight %}
|
|
|
|
|
|
|
|
|
|
### Related statements
|
|
|
|
|
- [CREATE VIEW](sql-ref-syntax-ddl-create-view.html)
|
|
|
|
|
- [DROP VIEW](sql-ref-syntax-ddl-drop-view.html)
|
|
|
|
|
- [CREATE DATABASE](sql-ref-syntax-ddl-create-database.html)
|
|
|
|
|
- [DROP DATABASE](sql-ref-syntax-ddl-drop-database.html)
|