There are several functions and operators used to work with NULL values in SQL. These functions and operators are used to handle, check, or manipulate NULL values in various ways. Some common ones include:

IS NULL: The IS NULL operator is used to check if a column or expression contains a NULL value. For example:

SELECT * FROM table WHERE column IS NULL;

IS NOT NULL: The IS NOT NULL operator is used to check if a column or expression does not contain a NULL value. For example:

SELECT * FROM table WHERE column IS NOT NULL;

COALESCE: The COALESCE function returns the first non-NULL expression in a list. If all expressions are NULL, it returns NULL.

SELECT COALESCE(column1, column2, 'Default') FROM table;

IFNULL (or ISNULL in some databases): This function is used to return a specified value if the expression is NULL.

SELECT IFNULL(column, 'Default') FROM table;

Checkout the video to learn more about NULL functions in SQL.