ALTER VIEW (Databricks SQL)

Alters metadata associated with the view. It can change the definition of the view, change the name of a view to a different name, set and unset the metadata of the view by setting TBLPROPERTIES.

RENAME

Renames the existing view. If the new view name already exists in the source database, a TableAlreadyExistsException is thrown. This operation does not support moving the views across databases.

Syntax

ALTER VIEW from_view_name RENAME TO to_view_name

Parameters

SET

Sets 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 do not exist, the key-value pairs are added to the properties.

Syntax

ALTER VIEW view_name SET TBLPROPERTIES ( property_key = property_val [ , ... ] )

property_key
  ` key_part1 [. ... ] `

Parameters

  • view_name

    Identifies the view to operate on.

  • property_key

    The property key. The key can consist of multiple parts separated by a dot.

UNSET view properties

Drops 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

ALTER VIEW view_name UNSET TBLPROPERTIES [ IF EXISTS ]  ( property_key [ , ... ] )

property_key
  ` key_part1 [. ... ] `

Parameters

  • view_name

    Identifies the view to operate on.

  • property_key

    The property key. The key can consist of multiple parts separated by a dot.

ALTER VIEW AS SELECT

Changes the definition of a view. The query must be valid and the view_name must exist.

Syntax

ALTER VIEW view_name AS query

ALTER VIEW statement does not support SET SERDE or SET SERDEPROPERTIES properties.

Parameters

  • view_name

    Identifies the view to operate on.

  • query

    The new definition of the view.

Examples

-- Rename only changes the view name.
-- The source and target databases of the view have to be the same.
-- Use qualified or unqualified name for the source and target view.
ALTER VIEW tempdb1.v1 RENAME TO tempdb1.v2;

-- Verify that the new view is created.
DESCRIBE TABLE EXTENDED tempdb1.v2;
+----------------------------+----------+-------+
|                    col_name|data_type |comment|
+----------------------------+----------+-------+
|                          c1|       int|   null|
|                          c2|    string|   null|
|                            |          |       |
|# Detailed Table Information|          |       |
|                    Database|   tempdb1|       |
|                       Table|        v2|       |
+----------------------------+----------+-------+

-- Before ALTER VIEW SET TBLPROPERTIES
DESC TABLE EXTENDED tempdb1.v2;
+----------------------------+----------+-------+
|                    col_name| data_type|comment|
+----------------------------+----------+-------+
|                          c1|       int|   null|
|                          c2|    string|   null|
|                            |          |       |
|# Detailed Table Information|          |       |
|                    Database|   tempdb1|       |
|                       Table|        v2|       |
|            Table Properties|    [....]|       |
+----------------------------+----------+-------+

-- Set properties in TBLPROPERTIES
ALTER VIEW tempdb1.v2 SET TBLPROPERTIES ('created.by.user' = "John", 'created.date' = '01-01-2001' );

-- Use `DESCRIBE TABLE EXTENDED tempdb1.v2` to verify
DESC TABLE EXTENDED tempdb1.v2;
+----------------------------+-----------------------------------------------------+-------+
|                    col_name|                                            data_type|comment|
+----------------------------+-----------------------------------------------------+-------+
|                          c1|                                                  int|   null|
|                          c2|                                               string|   null|
|                            |                                                     |       |
|# Detailed Table Information|                                                     |       |
|                    Database|                                              tempdb1|       |
|                       Table|                                                   v2|       |
|            Table Properties|[created.by.user=John, created.date=01-01-2001, ....]|       |
+----------------------------+-----------------------------------------------------+-------+

-- Remove the key `created.by.user` and `created.date` from `TBLPROPERTIES`
ALTER VIEW tempdb1.v2 UNSET TBLPROPERTIES ('created.by.user', 'created.date');

--Use `DESC TABLE EXTENDED tempdb1.v2` to verify the changes
DESC TABLE EXTENDED tempdb1.v2;
+----------------------------+----------+-------+
|                    col_name| data_type|comment|
+----------------------------+----------+-------+
|                          c1|       int|   null|
|                          c2|    string|   null|
|                            |          |       |
|# Detailed Table Information|          |       |
|                    Database|   tempdb1|       |
|                       Table|        v2|       |
|            Table Properties|    [....]|       |
+----------------------------+----------+-------+

-- Change the view definition
ALTER VIEW tempdb1.v2 AS SELECT * FROM tempdb1.v1;

-- Use `DESC TABLE EXTENDED` to verify
DESC TABLE EXTENDED tempdb1.v2;
+----------------------------+---------------------------+-------+
|                    col_name|                  data_type|comment|
+----------------------------+---------------------------+-------+
|                          c1|                        int|   null|
|                          c2|                     string|   null|
|                            |                           |       |
|# Detailed Table Information|                           |       |
|                    Database|                    tempdb1|       |
|                       Table|                         v2|       |
|                        Type|                       VIEW|       |
|                   View Text|   select * from tempdb1.v1|       |
|          View Original Text|   select * from tempdb1.v1|       |
+----------------------------+---------------------------+-------+