ALTER VIEW

通过使用另一个 QUERY 来更改现有视图。

Syntax

ALTER VIEW [ <database_name>. ]view_name [ (<column>, ...) ] AS SELECT query

Examples

CREATE VIEW tmp_view AS SELECT number % 3 AS a, avg(number) FROM numbers(1000) GROUP BY a ORDER BY a;

SELECT * FROM tmp_view;
+------+-------------+
| a    | avg(number) |
+------+-------------+
|    0 |       499.5 |
|    1 |       499.0 |
|    2 |       500.0 |
+------+-------------+

ALTER VIEW tmp_view(c1) AS SELECT * from numbers(3);

SELECT * FROM tmp_view;
+------+
| c1   |
+------+
|    0 |
|    1 |
|    2 |
+------+

Tag 操作

为视图分配或移除 Tag。Tag 必须先通过 CREATE TAG 创建。完整说明请参阅 SET TAG / UNSET TAG。

语法

ALTER VIEW [ IF EXISTS ] [ <database_name>. ]<view_name>
    SET TAG <tag_name> = '<value>' [, <tag_name> = '<value>' ...]

ALTER VIEW [ IF EXISTS ] [ <database_name>. ]<view_name>
    UNSET TAG <tag_name> [, <tag_name> ...]

示例

ALTER VIEW default.active_users SET TAG env = 'prod', owner = 'analytics';
ALTER VIEW default.active_users UNSET TAG env, owner;