I have 3 tables which are news (id, title, descrption)
, cat (id, title)
, newscat (id, newsID, catID)
. As you see each news
can relate to any or some cats
. I want one query to fetch all cat
s and if cat
is related to news
'checked'. I wrote this query:
SELECT
c.id, c.title, IF (nc.newsID = $newsID, 'checked', null) as checked
FROM
cat c
LEFT JOIN newscat nc ON c.id = nc.catID
but this doesn't work. Some cat
s come duplicate. What is the problem?
Using suggestion from Wr1t3r:
SELECT
c.id, c.title, IF (COUNT(IF(nc.newsID=$NewsID,1,NULL)) > 0, 'checked', null) as checked
FROM
cat c
LEFT JOIN newscat nc ON c.id = nc.catID
GROUP BY c.id
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