Categories:: Data metric functions

NULL_KEYWORD_COUNT (system data metric function)¶

Returns the count of non-NULL column values that are a text placeholder for a missing value, such as 'null' or 'n/a', rather than a SQL NULL.

This topic provides the syntax for calling the function directly. To learn how to associate the function with a table or view so it runs at regular intervals, see Associate a DMF.

Syntax¶

SNOWFLAKE.CORE.NULL_KEYWORD_COUNT(<query>)

Arguments¶

query: Specifies a SQL query that projects a single column.

Allowed data types¶

The column projected by the query must have the VARCHAR data type.

Returns¶

The function returns a NUMBER value. NULL values are not counted.

Usage notes¶

The function counts the values none, null, nil, nothing, and n/a. Matching is case-insensitive and ignores leading and trailing whitespace, including no-break spaces.
SQL NULL values, empty strings, and other placeholders such as na or - are not counted. To count SQL NULL values, use NULL_COUNT.

Example¶

Measure the number of text placeholders for missing values in the middle_name column:

SELECT SNOWFLAKE.CORE.NULL_KEYWORD_COUNT(
  SELECT
    middle_name
  FROM hr.tables.employees
);