Answers for "sql is empty"

sql not null

SELECT column_name FROM table_name 
WHERE column_name IS NOT NULL;

t sql null or empty string

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

sql if empty then

SELECT COALESCE(NULLIF(SomeColumn,''), ReplacementColumn)
FROM SomeTable

sql check for null and empty string

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