mysqli_fetch_array() foreach loop duplicates

Question

I'm performing a request on a database which returns an array. I'm using a foreach loop to go through the values.

Database (only 1 entry)

id | field1 | field2 | field3 | field4 | field5
---|--------|--------|--------|--------|--------
1  | value1 |        | value3 | value4 | value5

PHP Source code

$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
$q = mysqli_query($mysqli, "SELECT * FROM my_table");

echo "<ul>";
    while($q = mysqli_fetch_array($q))
    {
        foreach ($q as $key => $value)
        {
            if($value != NULL)
            {
                echo "<li>".$value . "</li>";

                // Line below used to show column name and corresponding value
                //echo "<li><strong>{$key}</strong> / <em>{$value}</em></li>";
            }
        }
    }
echo "</ul>";

Expected HTML output

<ul>
    <li>value1</li>
    <li>value3</li>
    <li>value4</li>
    <li>value5</li>
</ul>

Current output

<ul>
    <li>1</li>
    <li>1</li>
    <li>value1</li>
    <li>value1</li>
    <li>value3</li>
    <li>value3</li>
    <li>value4</li>
    <li>value4</li>
    <li>value5</li>
    <li>value5</li>
</ul>

Current issue

As you can see, I current have everything in double, and for some wierd reason, I'm getting the row ID, or so I assume considering I do not get a second row when I add a new row to the database.

Alternate code

Using the commented line, I get this output:

<ul>
    <li>0 / 1</li>
    <li>id / 1</li>
    <li>1 / value1</li>
    <li>field1 / value1</li>
    <li>3 / value3</li>
    <li>field3 / value3</li>
    <li>4 / value4</li>
    <li>field4 / value4</li>
    <li>5 / value5</li>
    <li>field5 / value5</li>
</ul>

From what I understand

A while loop would allow me to go through each row from the database.
A foreach loop is similar to a while loop, but instead of going through database entries, it goes through the key/value pairs from an array.

(Please feel free to correct me if I am wrong about these previous statements.)

Thinking outloud

I'm starting to wonder, as I write this question, if the while and foreach seem kind of redundant in that both seem would parse the values, probably causing my duplicates...?
Wouldn't the row number (in this case 1) be a key?

Maybe it is because $q being set as the mysqli_query and also being set during the while? Maybe try while($r = mysqli_fetch_array($q)) ? — Kenny Thompson
– Kenny Thompson, Commented Dec 18, 2013 at 3:56

AbraCadaver · Accepted Answer · 2017-05-01 20:07:08Z

8

By default, mysqli_fetch_array() returns both an Associative Array ($key => $value) and a Numeric Array (0 => value), which is why you're getting duplicates - some of the entries have the column name as the key, the others have a numeric index.

If you want an associative array, you could use:

 mysqli_fetch_array($q, MYSQLI_ASSOC);
 //or
 mysqli_fetch_assoc($q);

Or for a numeric array:

 mysqli_fetch_array($q, MYSQLI_NUM);
 //or
 mysqli_fetch_row($q);

For more info: http://www.php.net/manual/en/mysqli-result.fetch-array.php

edited May 1, 2017 at 20:07

AbraCadaver

79.2k7 gold badges75 silver badges91 bronze badges

answered Dec 18, 2013 at 4:00

user2074055

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