MySQL query from PHP returns incorrect results

Question

My MySQL table "tracks" has these two fields:

Id (Int)
Name (Varchar 255)

The values are:

1   Day 1
2   Day 2
3   Day 3

I am trying to retrieve all the tracks from PHP using this functions:

function getTracks() {
    $query = sprintf('select * from tracks');
    return contentRetrieverDataBaseQuery($query)->fetchAssoc();
}

function contentRetrieverDataBaseQuery($query) {
    $settings = contentRetrieverGetSettings();
    Database::addConnectionInfo('contentRetriever', 'default', $settings['database_connection']);
    db_set_active('contentRetriever');
    $result = db_query($query);
    db_set_active();
    return $result;
}

Running select * from event_tracks on phpmyadmin I get the results correctly.

When I do this:

$tracks = getTracks();
foreach ($tracks as $track) {
  echo $track['name'];
}

I get as an output "1D", which is the Id and the first letter of the Name.

What am I doing wrong?

EDIT: Corrected the name of the database

nowhere inside your contentRetrieveDataBaseQuery do you define $result... — Marc B
– Marc B, Commented May 19, 2015 at 19:12
Ok, now that my eyes are open, most likely the ->fetchAssoc() is returning a SINGLE row of data, which means that $tracks is a single level array, and $track['name'] is taking the string value in $track and trying to treat it as a string, meaning $foo = 'bar'; echo $foo[1] outputs a. - ['name'] will be parsed down to [0]. — Marc B
– Marc B, Commented May 19, 2015 at 19:17
Use fetchAll instead of fetchAssoc to get all the results as a multi-dimensional array. — Barmar
– Barmar, Commented May 19, 2015 at 19:19

Marc B · Accepted Answer · 2015-05-19 19:40:10Z

1

->fetchAssoc() invariably returns a single row of query results, meaning that your array is a single record, and your loop will be putting that row's string values into $track. You then use $track as if it was an array, producing the following code equivalent:

$arr = array('abc', 'def'); // your one row of query results.
foreach($arr as $value) {
   // $value is now 'abc';
   echo $value['name']; // parsed/executed as $value[0];
  // output is 'a'
}

Strings can be treated as arrays of characters, which is why PHP didn't complain about $tracks['name']. It simply treated as ['name'] as a goofy attempt at using a non-numeric array index, and converted it to 0.

answered May 19, 2015 at 19:40

Marc B

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