为什么mysql_fetch_array会输出多个重复的结果

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.

Answer 1

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