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