is not null or empty sql code example

Example 1: t sql null or empty string

select * from vendor
where isnull(vendor_email,'') = ''

Example 2: sql check for null and empty string

IF ISNULL(@param) OR @param = '' THEN doSomething...

Example 3: sql is not null

The reverse of NULL. Tests for values that aren’t empty / NULL
"Tests for empty (NULL) values.
Example: Returns users that haven’t given a contact number.
SELECT * FROM users
WHERE contact_number IS NULL;"