Views

DDL - Views

A view is a virtual table based on the result set of a SQL statement. It derives its fields from a SELECT statement. You can do anything with a HEAVY.AI view query that you can do in a non-view HEAVY.AI query.

Nomenclature Constraints

View object names must use the NAME format, described in regex notation as:

[A-Za-z_][A-Za-z0-9\$_]*

CREATE VIEW

Creates a view based on a SQL statement.

Example

CREATE VIEW view_movies
AS SELECT movies.movieId, movies.title, movies.genres, avg(ratings.rating)
FROM ratings
JOIN movies on ratings.movieId=movies.movieId
GROUP BY movies.title, movies.movieId, movies.genres;

You can describe the view as you would a table.

\d view_movies
VIEW defined AS: SELECT  movies.movieId, movies.title, movies.genres,
avg(ratings.rating) FROM ratings JOIN movies ON ratings.movieId=movies.movieId
GROUP BY movies.title, movies.movieId, movies.genres
Column types:
    movieId INTEGER,
    title TEXT ENCODING DICT(32),
    genres TEXT ENCODING DICT(32),
    EXPR$3 DOUBLE

You can query the view as you would a table.

SELECT title, EXPR$3 from view_movies where movieId=260;
Star Wars: Episode IV - A New Hope (1977)|4.048937

DROP VIEW

Removes a view created by the CREATE VIEW statement. The view definition is removed from the database schema, but no actual data in the underlying base tables is modified.

Example

DROP VIEW IF EXISTS v_reviews;