nullif()

Arguments & returns

Macro

Overload link	`a`	`b`	Returns
#01	`unknown`	`unknown`	`unknown`

CASE
  WHEN ((a = b)) THEN (NULL)
  ELSE a
END

Used in larger rewrites 3

These examples use nullif as one part of a larger SQL translation.

SELECT REGEXP_EXTRACT(abc, 'pattern(group)', 2) FROM table

In DuckDB

SELECT REGEXP_EXTRACT(NULLIF(SUBSTRING(abc, 2), ''), 'pattern(group)', 1) FROM "table"

a / b

In DuckDB

a / NULLIF(b, 0)

REGEXP_SUBSTR(subject, pattern, 3)

In DuckDB

REGEXP_EXTRACT(NULLIF(SUBSTRING(subject, 3), ''), pattern)