SQL remove duplicates with INNER JOIN - sql

Question

I have tried multiple things to get rid of all the duplicates in my query result, none of them worked. I tried DISTINCT and GROUP BY.
DISTINCT won't do anything at all and with GROUP BY I keep getting errors.
My Query:
SELECT
categorie.categorie_id AS categorie,
categorie.categorie_nummer,
categorie.naam,
product.product_id, product.product_naam,
foto.foto_id, foto.foto1,
item.prijs, item.item_id
FROM
((((((categorie
INNER JOIN
behoort_tot ON categorie.categorie_id = behoort_tot.categorie_id)
INNER JOIN
product ON behoort_tot.product_id = product.product_id)
INNER JOIN
heeft ON product.product_id = heeft.product_id)
INNER JOIN
foto ON heeft.foto_id = foto.foto_id)
INNER JOIN
is_een_1 ON product.product_id = is_een_1.product_id)
INNER JOIN
item ON is_een_1.item_id = item.item_id)
WHERE
(categorie.categorie_id = ?)
Thanks in advance

Answer 1

WITH TEMP AS
(
SELECT categorie.categorie_id AS categorie, categorie.categorie_nummer, categorie.naam,
product.product_id, product.product_naam, foto.foto_id, foto.foto1, item.prijs, item.item_id,
ROW_NUMBER()
OVER (PARTITION BY categorie.categorie_id ORDER BY categorie.categorie_id) As ROW_NO
FROM ((((((categorie INNER JOIN
behoort_tot ON categorie.categorie_id = behoort_tot.categorie_id)
INNER JOIN
product ON behoort_tot.product_id = product.product_id) INNER JOIN
heeft ON product.product_id = heeft.product_id) INNER JOIN
foto ON heeft.foto_id = foto.foto_id) INNER JOIN
is_een_1 ON product.product_id = is_een_1.product_id) INNER JOIN
item ON is_een_1.item_id = item.item_id)
)
SELECT * FROM TEMP WHERE ROW_NO = 1;
I do see that you are trying to sort out using the categories.Try this.I`m sorting it using the row_number function and assuming that you are using sql server