loop

The loop table function in ClickHouse is used to return query results in an infinite loop.

Syntax

SELECT ... FROM loop(database, table);
SELECT ... FROM loop(database.table);
SELECT ... FROM loop(table);
SELECT ... FROM loop(other_table_function(...));

Arguments

Argument	Description
database	database name.
table	table name.
other_table_function(...)	other table function. Example: SELECT * FROM loop(numbers(10)); other_table_function(...) here is numbers(10).

Returned values

Infinite loop to return query results.

Examples

Selecting data from ClickHouse:

SELECT * FROM loop(test_database, test_table);
SELECT * FROM loop(test_database.test_table);
SELECT * FROM loop(test_table);

Or using other table functions:

SELECT * FROM loop(numbers(3)) LIMIT 7;
   ┌─number─┐
1. │      0 │
2. │      1 │
3. │      2 │
   └────────┘
   ┌─number─┐
4. │      0 │
5. │      1 │
6. │      2 │
   └────────┘
   ┌─number─┐
7. │      0 │
   └────────┘

SELECT * FROM loop(mysql('localhost:3306', 'test', 'test', 'user', 'password'));
...