MYSQL PHP内连接比较不同的值

Question

I have this two columns:

The first column name is TAGS and the second column name is PORTTAG.

I want to get all tags.nome that are not to be used on porttag.tag with porttag.port = 1

 $mysqli->query("SELECT nome FROM tags INNER JOIN porttag ON porttag.tag != tags.nome WHERE porttag.port = '".$_GET['edit']."'"); 

But without success!

Can you help me?

Answer 1

It seems as though you need to use the not exists operator:

SELECT nome 
FROM   tags t
WHERE  NOT EXISTS (SELECT * 
                   FROM   porttag p 
                   WHERE  p.tag = tags.nome AND p.port = 1)

Answer 2

I want to get all tags.nome that are not to be used on porttag.tag with porttag.port = 1

This makes me think of this:

select t.*
from tags t
where not exists (select 1 from porttag pt where pt.port = 1 and pt.tag = t.nome);

However, you have something very strange in your data model. The link between the tables should be based on the id not the name.