Something wrong in Preprending string with spaces - sql

Question

Based on the suggestion in this post Right pad a string with variable number of spaces
For testing purposes, I created a table and added the following rows
CREATE TABLE CharTest (
ID int,
CharField char(6) NULL
);
INSERT INTO CharTest
VALUES (1, ' 90');
INSERT INTO CharTest
VALUES (1, ' 89');
INSERT INTO CharTest
VALUES (1, NULL);
INSERT INTO CharTest
VALUES (1, ' 91');
INSERT INTO CharTest
VALUES (1, ' 90');
I then tried executing this query
DECLARE #lCharField char(6)
SET #lCharField = '90'
SELECT CharField FROM CharTest
where CharField = RIGHT(space(6) + #lCharField, 6)
it returned no rows.
I checked the output of the following queries
SELECT RIGHT(space(6) + #lCharField, 6) FROM CharTest
SELECT RIGHT(' ' + #lCharField, 6) FROM CharTest
and it doesn't seem to right-pad or pre-prend the spaces as expected.
Any help in pointing out what I am doing wrong is highly appreciated.

Answer 1

The issue is this code:
DECLARE #lCharField char(6);
SET #lCharField = '90';
You think the result is '90' but it is really '90 '. That throws everything off. Use:
DECLARE #lCharField varchar(6);
SET #lCharField = '90';
Here is a db<>fiddle.
Note that finicky spaces are one important reason why varchar() is used -- say -- 100 times more often than char(). The only really good use for char() is for columns that are of fixed width, such as ISO3 code for counties.