MYSQL Select on two values one column

Question

I need to select a row from my mysql table.

In the table there are two rows with one equal value.

TABLE
-----
articleId
keywordId

Now I need to select an article, that has keyword Id = 1, as well as keyword Id = 12.

Every link to a keyword has its own record.

How can I do one select query to know, if there is an article, that matches the two keywords?

Answer 1

Try this:

SELECT *  
FROM tablename 
WHERE keywordId IN (1, 12) 
GROUP BY articleId 
HAVING COUNT(*) = 2; 

Check the SQL FIDDLE DEMO

Answer 2

This is called Relation Division. Here is one way to do so:

SELECT * 
FROM tablename 
WHERE articleId IN
(
   SELECT articleId
   FROM tablename
   WHERE KeywordId IN (1, 2) 
   GROUP BY articleId
   HAVING COUNT(KeywordId ) = 2
);;