1: If you just want to match " " as an empty string, then use the WHERE clause like this:
WHERE DATALENGTH(COLUMN) > 0
2: But, if you want to count any string which consists of entire spaces as empty then use the WHERE clause like this :
WHERE COLUMN <> ''
The above code will not return NULL values when they are used in a WHERE clause. And NULL will evaluate as UNKNOWN for these rather than the TRUE value.
CREATE TABLE T
(
C VARCHAR(10)
);
INSERT INTO T
VALUES ('A'),
(''),
(' '),
(NULL);
SELECT *
FROM T
WHERE C <> ''
The above code will return only the single row A. The rows that have the NULL or an empty string or a string consisting entirely of spaces are all excluded by this query.
Visit this SQL server certification to learn SQL Full Package.
