CREATE VIEW

Description

1. This statement is used to create a logical view
2. Grammar:

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

9. Explain:

11. 1. Views are logical views without physical storage. All queries on views are equivalent to sub-queries corresponding to views.
12. 2. query_stmt is arbitrarily supported SQL.

example

1. 1. Create view example_view on example_db

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

8. 2. Create view with comment

10. CREATE VIEW example_db.example_view
11. (
12. k1 COMMENT "first key",
13. k2 COMMENT "second key",
14. k3 COMMENT "third key",
15. v1 COMMENT "first value"
16. )
17. COMMENT "my first view"
18. AS
19. SELECT c1 as k1, k2, k3, SUM(v1) FROM example_table
20. WHERE k1 = 20160112 GROUP BY k1,k2,k3;

keyword

1. CREATE,VIEW