IS_NULL

Description

The IS_NULL function is used to determine whether a given expression (expr) is NULL. If the expression is NULL, it returns true; otherwise, it returns false. This function has the same effect as the IS NULL statement in SQL.

Syntax

is_null(expr)

Parameter Description

• expr: An expression of any type.

Return Result

Returns a boolean value, true if the expression is NULL, otherwise false.

Usage Example

1. Determine if a number is NULL:

   > SELECT is_null(NULL);
   true
   

2. Determine if a string is NULL:

   > SELECT is_null('');
   false
   

3. Using the IS_NULL function in queries:

   > SELECT name, age, is_null(address) AS is_address_null FROM users;
   

The above query will return the results of whether the name, age, and address in the user table are NULL.