Spark SQL Guide

CREATE VIEW

Description

Views are based on the result-set of an SQL query. CREATE VIEW constructs a virtual table that has no physical data therefore other operations like ALTER VIEW and DROP VIEW only change metadata.

Syntax

CREATE [ OR REPLACE ] [ [ GLOBAL ] TEMPORARY ] VIEW [ IF NOT EXISTS ] view_identifier
    create_view_clauses AS query

Parameters

OR REPLACE
If a view of same name already exists, it will be replaced.
[ GLOBAL ] TEMPORARY
TEMPORARY views are session-scoped and will be dropped when session ends because it skips persisting the definition in the underlying metastore, if any. GLOBAL TEMPORARY views are tied to a system preserved temporary database `global_temp`.
IF NOT EXISTS
Creates a view if it does not exists.
view_identifier
Specifies a view name, which may be optionally qualified with a database name.

Syntax: [ database_name. ] view_name
create_view_clauses
These clauses are optional and order insensitive. It can be of following formats.
  • [ ( column_name [ COMMENT column_comment ], ... ) ] to specify column-level comments.
  • [ COMMENT view_comment ] to specify view-level comments.
  • [ TBLPROPERTIES ( property_name = property_value, ... ) ] to add metadata key-value pairs.
query
A SELECT statement that constructs the view from base tables or other views.

Examples

-- Create or replace view for `experienced_employee` with comments.
CREATE OR REPLACE VIEW experienced_employee
    (ID COMMENT 'Unique identification number', Name) 
    COMMENT 'View for experienced employees'
    AS SELECT id, name FROM all_employee
        WHERE working_years > 5;

-- Create a global temporary view `subscribed_movies` if it does not exist.
CREATE GLOBAL TEMPORARY VIEW IF NOT EXISTS subscribed_movies 
    AS SELECT mo.member_id, mb.full_name, mo.movie_title
        FROM movies AS mo INNER JOIN members AS mb 
        ON mo.member_id = mb.id;