The * expression can be used in a SELECT statement to select all columns that are projected in the FROM clause.

SELECT * FROM tbl;

The * expression can be modified using the EXCLUDE and REPLACE.

EXCLUDE Clause

EXCLUDE allows us to exclude specific columns from the * expression.

SELECT * EXCLUDE (col) FROM tbl;

Replace Clause

REPLACE allows us to replace specific columns with different expressions.

SELECT * REPLACE (col / 1000 AS col) FROM tbl;

COLUMNS

The COLUMNS expression can be used to execute the same expression on multiple columns. Like the * expression, it can only be used in the SELECT clause.

CREATE TABLE numbers(id int, number int);
INSERT INTO numbers VALUES (1, 10), (2, 20), (3, NULL);
SELECT MIN(COLUMNS(*)), COUNT(COLUMNS(*)) from numbers;

The * expression in the COLUMNS statement can also contain EXCLUDE or REPLACE, similar to regular star expressions.

SELECT MIN(COLUMNS(* REPLACE (number + id AS number))), COUNT(COLUMNS(* EXCLUDE (number))) from numbers;

COLUMNS expressions can also be combined, as long as the COLUMNS contains the same (star) expression:

SELECT COLUMNS(*) + COLUMNS(*) FROM numbers;

Finally, COLUMNS supports passing a regex in as a string constant:

SELECT COLUMNS('(id|numbers?)') FROM numbers;