避免使用空值VS NULL更新MySQL

Question

I have a form, that has some optional inputs, that the user can skip from updating, those inputs can be empty, the issue is when I update a column that is set to NULL, the query will update that column to a blank "" instead of keeping it as null.

My concern is how efficient is this on MySQL specially large tables, is there a difference in performance when values are set to Blank VS NULL. If yes then I will make sure all empty inputs are updated as NULL.

This is the code am using to avoid blank, is there a better way to it?

#Avoid blank with NULL
$value1 = !empty($_POST['input1']) ? $_POST['input1'] : NULL;
$value2 = !empty($_POST['input2']) ? $_POST['input2'] : NULL;

Answer 1

There's a good conversation about it here: MySQL: NULL vs ""

Answer from /u/degenerate

I found out that NULL vs "" is insignificant in terms of disk-space and performance.

There's some others discussing that it's faster to search for a "null bit" than checking that a string is ''. That question is 9 years old, so we have come a long way hardware wise since then, and the difference is probably negligible. As a DBA, I'd recommend using nulls appropriately :)