kevinyu98 commented on a change in pull request #25573:
[SPARK-28833][DOCS][SQL] Document ALTER VIEW command
URL: https://github.com/apache/spark/pull/25573#discussion_r344475265
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File path: docs/sql-ref-syntax-ddl-alter-view.md
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@@ -19,4 +19,78 @@ license: |
limitations under the License.
---
-**This page is under construction**
+### Description
+The `ALTER VIEW` statement changes various auxiliary properties of a view.
+
+
+#### Rename view
+Rename the existing view. If the view name already exists in the database, an
exception is thrown. This operation does
+support moving the views cross databases.
+##### Syntax
+{% highlight sql %}
+ALTER VIEW viewIdentifier RENAME TO viewIdentifier
+viewIdentifier:= [db_name.]view_name
+{% endhighlight %}
+
+
+#### Set view properties
+Set one or more properties of an existing view. The properties are the key
value pairs. If the properties' keys exist,
+the values are replaced with the new values. If the properties' keys does not
exist, the key value pairs are added into
+the properties.
+##### Syntax
+{% highlight sql %}
+ALTER VIEW viewIdentifier SET TBLPROPERTIES (key1=val1, key2=val2, ...)
+viewIdentifier:= [db_name.]view_name
+{% endhighlight %}
+
+
+#### Drop view properties
+Drop one or more properties of an existing view. If the specified keys do not
exist, an exception is thrown. Use
+`IF EXISTS` to avoid the exception.
+##### Syntax
+{% highlight sql %}
+ALTER VIEW viewIdentifier UNSET TBLPROPERTIES [IF EXISTS] (key1=val1,
key2=val2, ...)
+viewIdentifier:= [db_name.]view_name
+{% endhighlight %}
+
+
+#### Alter View As Select
+`ALTER VIEW AS SELECT` statement changes the definition of a view, the
`select_statement` must valid, and the `VIEW`
+must exist.
+##### Syntax
+{% highlight sql %}
+ALTER VIEW viewIdentifier AS select_statement
+viewIdentifier:= [db_name.]view_name
+select_statement:= [select_statement](sql-ref-syntax-qry-select.html)
+{% endhighlight %}
+
+
+#### Example
+{% highlight sql %}
+-- Rename only change the view name.
+-- The source and target databases of the view have to be the same, use
qualified or unqualified name for the target view
+ALTER VIEW tempdb.view1 RENAME TO view2
+{% endhighlight %}
+
+{% highlight sql %}
+-- Use `DESC TABLE EXTENDED tempdb.view1` before and after the `ALTER VIEW`
statement to verify the changes.
+ALTER VIEW tempdb.view1 SET TBLPROPERTIES ('propKey1' = "propVal1", 'propKey2'
= "propVal2" )
+{% endhighlight %}
+
+{% highlight sql %}
+-- Use `DESC TABLE EXTENDED tempdb.view1` before and after the `ALTER VIEW` to
verify the change.
+ALTER VIEW tempdb.view1 UNSET TBLPROPERTIES ('propKey1')
+{% endhighlight %}
+
+{% highlight sql %}
+-- Do the select on tempdb.view1 before and after the `ALTER VIEW` statement
to verify.
+ALTER VIEW tempdb.view1 AS SELECT * FROM tempdb.view2
+{% endhighlight %}
+
+#### Related Statements
+[describe-table](sql-ref-syntax-aux-describe-table.html)
+[create-view](sql-ref-syntax-ddl-create-view.html)
+[drop-view](sql-ref-syntax-ddl-drop-view.html)
Review comment:
👍
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