NVL and IFNULL

Applies to: ✅ Data 360 SQL ✅ Tableau Hyper API

IFNULL and NVL both return a replacement expression when the input expression is NULL.

1nvl(<expr>, <replacement>)
2ifnull(<expr>, <replacement>)

• <expr>: Expression to check for NULL.
• <replacement>: Expression returned when <expr> is NULL.

Returns <expr> when it isn’t NULL; otherwise, returns <replacement>. Argument types must be compatible.

• Requires exactly two arguments.
• IFNULL is an alias of NVL.
• Equivalent to COALESCE with these two arguments.

Return the replacement when the first expression is NULL.

1SELECT nvl(NULL, 99) AS result;

Returns 99.

IFNULL returns the same result:

1SELECT ifnull(NULL, 99) AS result;

Returns 99.

Return the first expression when it isn’t NULL.

1SELECT nvl(42, 0) AS result;

Returns 42.

• COALESCE
• NULLIFZERO
• ZEROIFNULL