ALTER VIEW
Description
The ALTER VIEW statement can alter 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 View
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 view_identifier RENAME TO view_identifierParameters
view_identifier-
Specifies a view name, which may be optionally qualified with a database name.
Syntax:[ database_name. ] view_name
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 do not exist, the key value pairs are added into the properties.
Syntax
ALTER VIEW view_identifier SET TBLPROPERTIES ( property_key = property_val [ , ... ] )Parameters
view_identifier-
Specifies a view name, which may be optionally qualified with a database name.
Syntax:[ database_name. ] view_name property_key-
Specifies the property key. The key may consists of multiple parts separated by dot.
Syntax:[ key_part1 ] [ .key_part2 ] [ ... ]
UNSET 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
ALTER VIEW view_identifier UNSET TBLPROPERTIES [ IF EXISTS ] ( property_key [ , ... ] )Parameters
view_identifier-
Specifies a view name, which may be optionally qualified with a database name.
Syntax:[ database_name. ] view_name property_key-
Specifies the property key. The key may consists of multiple parts separated by dot.
Syntax:[ key_part1 ] [ .key_part2 ] [ ... ]
ALTER View AS SELECT
ALTER VIEW view_identifier AS SELECT statement changes the definition of a view, the SELECT statement must be valid,
and the view_identifier must exist.
Syntax
ALTER VIEW view_identifier AS select_statementParameters
view_identifier-
Specifies a view name, which may be optionally qualified with a database name.
Syntax:[ database_name. ] view_name select_statement- Specifies the definition of the view, detail check select_statement
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 | |
+----------------------------+---------------------------+-------+Related Statements
Note:
ALTER VIEW statement does not support SET SERDE or SET SERDEPROPERTIES properties