Question

I have two databases – one for articles and the another for the articles’ meta information (Like author, date, category and atc.). I have the following columns in meta table: ID, article id, meta type and meta value. I wonder how can I join these two tables to get both – article and meta information – with one mysql query. The article id isn’t unique in meta table, that is why I can’t figure out how to access specific meta type and according value for the article…

Here is the mysql I’m tried to use:

SELECT products.*, product_meta.meta_value
FROM products
LEFT JOIN product_meta ON products.ID = product_meta.product_id

but this query doesn’t seem to be what I need. I there are for example two records in articles table and ten in meta table this code displays ten results instead of two:

$products = mysql_query("SELECT products.*, product_meta.meta_value
                         FROM products
                         LEFT JOIN product_meta ON products.ID = product_meta.product_id") or die(mysql_error());

while ($product = mysql_fetch_assoc($products)) {
    echo $product["title"];
}

Can anyone please help?

Answer 1

try the following sql statements:

SELECT products.*, product_meta.meta_value
FROM products LEFT OUTER JOIN product_meta 
ON products.ID = product_meta.product_id
WHERE product_meta.product_id NOT IS NULL