view - ClickHouse Documentation

Turns a subquery into a table. The function implements views (see CREATE VIEW). The resulting table does not store data, but only stores the specified SELECT query. When reading from the table, ClickHouse executes the query and deletes all unnecessary columns from the result.

Syntax

view(subquery)

Arguments

subquery — SELECT query.

Returned value

A table.

Examples

Input table:

┌─id─┬─name─────┬─days─┐
│  1 │ January  │   31 │
│  2 │ February │   29 │
│  3 │ March    │   31 │
│  4 │ April    │   30 │
└────┴──────────┴──────┘

Query

SELECT * FROM view(SELECT name FROM months);

Response

┌─name─────┐
│ January  │
│ February │
│ March    │
│ April    │
└──────────┘

You can use the view function as a parameter of the remote and cluster table functions:

Query

SELECT * FROM remote(`127.0.0.1`, view(SELECT a, b, c FROM table_name));

Query

SELECT * FROM cluster(`cluster_name`, view(SELECT a, b, c FROM table_name));

View Table Engine

​Syntax

​Arguments

​Returned value

​Examples

​Related

Syntax

Arguments

Returned value

Examples

Related