Why mysql_fetch_array outputs multiple duplicate results

Question

From this simple query, I could not figure out why I am getting the repeated result one in [0] and another in [m_id]. I believe the result from given query must display only two values.

$sql="SELECT m.m_id, m.work FROM mun as m WHERE m.mun_id=7 ";
$rslt=mysql_query($sql);
$result=mysql_fetch_array($rslt);
print_r($result);

Output:

Array
    (
        [0] => 7
        [m_id] => 7
        [1] => 260
        [work] => 260
    )

Can somebody figure me out what I am doing wrong. Thank you.

a) don't use mysql - it's been deprecated and in PHP7 removed. use mysqli or PDO instead. b) you're not doing something wrong, you're just getting associative and numeric indizes. the fix is using mysql_fetch_assoc instead - but again: switch to mysqli or PDO — Franz Gleichmann
– Franz Gleichmann, Commented Feb 22, 2017 at 8:28

Aziz · Accepted Answer · 2017-02-22 08:36:11Z

4

That's the normal behavior of mysql_fetch_array. It provides both numerical and associative indices.

If you want only one of them, use mysql_fetch_assoc or mysql_fetch_row

$result=mysql_fetch_row($rslt);

Array
    (
        [0] => 7
        [1] => 260
    )

or

$result=mysql_fetch_assoc($rslt);

Array
    (
        [m_id] => 7
        [work] => 260
    )

It's also worth mentioning that you can get this behavior using mysql_fetch_array by passing a second argument.

// same as mysql_fetch_row
$result=mysql_fetch_array($rslt, MYSQL_NUM);

and

// same as mysql_fetch_assoc
$result=mysql_fetch_array($rslt, MYSQL_ASSOC);

More info: http://php.net/manual/en/function.mysql-fetch-array.php

edited Feb 22, 2017 at 8:36

answered Feb 22, 2017 at 8:28

Aziz

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Comments

Spectorsky · Accepted Answer · 2017-02-22 08:53:58Z

The description of mysql_fetch_array is the following:

array mysql_fetch_array ( resource $result [, int $result_type = MYSQL_BOTH ] )

where the second optional parameter is:

The type of array that is to be fetched. It's a constant and can take the following values: MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH.

And about return value:

The type of returned array depends on how result_type is defined. By using MYSQL_BOTH (default), you'll get an array with both associative and number indices. Using MYSQL_ASSOC, you only get associative indices (as mysql_fetch_assoc() works), using MYSQL_NUM, you only get number indices (as mysql_fetch_row() works).

It is cited from http://php.net/manual/en/function.mysql-fetch-array.php.

So, in your case, default MYSQL_BOTH was applied. I'm sure that the following must solve:

$result=mysql_fetch_array($rslt, MYSQL_ASSOC);

or

$result=mysql_fetch_array($rslt, MYSQL_NUM);

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