Table Functions
Table functions are methods for constructing tables.
You can use table functions in:
FROM clause of the
SELECT
query.The method for creating a temporary table that is available only in the current query. The table is deleted when the query finishes.
CREATE TABLE AS table_function() query.
It's one of the methods of creating a table.
INSERT INTO TABLE FUNCTION query.
warning
You can’t use table functions if the allow_ddl setting is disabled.
Function | Description |
---|---|
file | Creates a File-engine table. |
merge | Creates a Merge-engine table. |
numbers | Creates a table with a single column filled with integer numbers. |
remote | Allows you to access remote servers without creating a Distributed-engine table. |
url | Creates a Url-engine table. |
mysql | Creates a MySQL-engine table. |
postgresql | Creates a PostgreSQL-engine table. |
jdbc | Creates a JDBC-engine table. |
odbc | Creates a ODBC-engine table. |
hdfs | Creates a HDFS-engine table. |
s3 | Creates a S3-engine table. |
sqlite | Creates a sqlite-engine table. |
note
Only these table functions are enabled in readonly mode : null, view, viewIfPermitted, numbers, numbers_mt, generateRandom, values, cluster, clusterAllReplicas