View

Views (logical views) are stored queries that encapsulate one or multiple SELECT statements. Views dynamically access and compute database data when executed. Views are read-only and can reference any combination of tables and other views.

Views can be used for the following purposes:

To simplify access or provide secure access by hiding complex SELECT statements from users. For example, you can create a view that displays only the data users need from various tables while hiding sensitive data in those tables.
To encapsulate details of table structures that may change over time behind a consistent user interface.

Unlike materialized views, logical views are not materialized, which means they do not store data on disk. Therefore, they have the following limitations:

When the underlying table data changes, Doris does not need to refresh the view data. However, accessing and computing data through views can incur some overhead.
Views do not support insert, delete, or update operations.

Creating View

The syntax for creating a logical view is as follows:

CREATE VIEW [IF NOT EXISTS]
 [db_name.]view_name
 (column1[ COMMENT "col comment"][, column2, ...])
AS query_stmt

Explanation:

Views are logical and have no physical storage. All queries on views are equivalent to queries on the corresponding subquery of the view.
query_stmt is any supported SQL statement.

Example:

Creating a view named example_view in the example_db database:

CREATE VIEW example_db.example_view (k1, k2, k3, v1)
AS
SELECT c1 as k1, k2, k3, SUM(v1) FROM example_table
WHERE k1 = 20160112 GROUP BY k1,k2,k3;

Creating a view with comments:

CREATE VIEW example_db.example_view
(
    k1 COMMENT "first key",
    k2 COMMENT "second key",
    k3 COMMENT "third key",
    v1 COMMENT "first value"
)
COMMENT "my first view"
AS
SELECT c1 as k1, k2, k3, SUM(v1) FROM example_table
WHERE k1 = 20160112 GROUP BY k1,k2,k3;

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Creating View​

View

Creating View