MySQL查询以选择表2中与表1匹配的所有结果

Question

I have pages stored in the database, and another table that stores translations of that same page:

Table page_pages:

ID    Title        Content
1     First Page   Stuff...
2     Second Page  More stuff...

Table page_translations:

ID    PageID    LanguageID    Title             Content
1     1         2             Primero pagina    Cosas...

So, right now I am querying the page_pages table to get the page information:

$query = SELECT * FROM page_pages WHERE ID = 1

How do I adjust this query to select translations that exist with the PageID AS Translations , and have that be it's own array with the LanguageID as the array keys?

This way, I can check if a translation exists like:

$language_id = 1;

if (isset($query['Translations'][$language_id])) {
  echo $query['Translations'][$language_id]['Title'];

} else {
  echo $query['Title'];
}

Answer 1

You need to use MySQL's group_concat function with 'left join', eg:

SELECT
    pp.id,
    pp.title,
    pp.content,
    group_concat(pl.language_id) AS languages
FROM
    page_pages pp
LEFT JOIN page_translations pl ON pp.id = pl.pageID
WHERE
    pp.id = 1
GROUP BY
    pp.id;

Here's the SQL Fiddle .