isnull function

Applies to: Databricks SQL Databricks Runtime

Returns true if expr is NULL. This function is a synonym for is null operator.

Syntax

isnull(expr)

Arguments

• expr: An expression of any type.

Returns

A BOOLEAN.

If expr is a VARIANT result of a:

• JSON path expression with a valid path,
• parse_json function,
• variant_explode table-valued function, or
• variant_explode_outer table-valued function

the result is always false. Use the is_variant_null function function to check if the VARIANT encoded value is NULL, or cast the VARIANT to a specific type and check if the result is NULL.

Examples

> SELECT isnull(1);
 false

> SELECT isnull(NULL:INTEGER);
 true

> SELECT isnull(parse_json('{"key": null}'):key);
 false

> SELECT isnull(parse_json('{"key": null}'):key::STRING);
 true

> SELECT isnull(parse_json('{"key": null}'):wrongkey);
 true

> SELECT is_variant_null(parse_json('{"key": null}'):key);
 true

Related functions

• isnotnull function
• isnan function
• is null operator
• is_variant_null function