Inefficient SQL Query

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温柔的废话 2021-02-19 08:08

I\'m building a simple web app at the moment that I\'ll one day open source. As it stands at the moment, the nav is generated on every page load (which will change to be cached

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一整个雨季 (楼主)

2021-02-19 08:56

You can run this query:

SELECT c.id AS cid, c.slug AS cslug, c.name AS cname,
    s.id AS sid, s.name AS sname
FROM categories AS c
    LEFT JOIN snippets AS s ON s.category = c.id
WHERE c.live=1
ORDER BY c.name, s.name

Then iterate thru the results to create the proper heading like:

// last category ID
$lastcid = 0;
while ($r = $navQuery->fetch_object ()) {

    if ($r->cid != $lastcid) {
        // new category

        // let's close the last open category (if any)
        if ($lastcid)
            printf ('

');

        // save current category
        $lastcid = $r->cid;

        // display category
        printf ('%s', $r->cslug, $r->cname);

        // display first snippet
        printf ('
%s', $r->cslug, $r->sname, $r->sname);

    } else {

        // category already processed, just display snippet

        // display snippet
        printf ('%s', $r->cslug, $r->sname, $r->sname);
    }
}

// let's close the last open category (if any)
if ($lastcid)
    printf ('');

Note that I used printf but you should use your own function instead which wraps around printf, but runs htmlspecialchars thru the parameters (except the first of course).

Disclaimer: I do not necessarily encourage such use of

This code is just here to show the basic idea of processing hierarchical data got with one query.

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