PHP MySQL查询返回“数组”

Question

I feel like there is a relatively simple answer to this question, and it may have been asked before but I cannot see it.

I have the following PHP function:

$uniqueId=mysql_query("SELECT MAX(unique_id) FROM my_db.table");
$urlnum=mysql_fetch_row($uniqueId);
echo "http://yourdomain.com/display.php?urlid=".$urlnum;

When I submit the form I am getting it returning " http://yourdomain.com/display.php?urlid=Array " submitting "Array" instead of the actual unique ID from my DB.

What I would like is to have the most recently added auto-incremental unique ID from the DB be added to the end of the URL string on form submit.

Any tips as to what I am doing wrong?

Thanks guys.

Answer 1

As per the doc

array mysql_fetch_row ( resource $result )

Returns a numerical array that corresponds to the fetched row and moves the internal data pointer ahead.

http://php.net/manual/en/function.mysql-fetch-row.php

So you should do as

$urlnum=mysql_fetch_row($uniqueId);
echo "http://yourdomain.com/display.php?urlid=".$urlnum[0];

BTW you are using deprecated function, you should start using mysqli or PDO with prepared statement

Answer 2

The return from of mysql_fetch_row is an array (even if there is only one field requested in your query), so the code is doing what you asked it to do. What you probably want is to reference the array index that contains the value you want. Something like

echo "http://yourdomain.com/display.php?urlid=".$urlnum[0];

where 0 is the array index that contains the urlid you want.

Answer 3

$urlnum is an array and you cannot print an array with echo

use print_r or var_dump

http://php.net/manual/en/function.print-r.php

Answer 4

Try this:

var_dump($urlnum);

$urlnum is an array and can't be echoed.

Then you can see where your value is, in what index that is, and extract it like this:

$index = 0;
$result = $urlnum[$index];

echo "http://yourdomain.com/display.php?urlid=".$result;

Answer 5

here you fetch the row so you must be give index number or column row like this..

$uniqueId=mysql_query("SELECT MAX(unique_id) FROM my_db.table");
$urlnum=mysql_fetch_row($uniqueId);
echo "http://yourdomain.com/display.php?urlid=".$urlnum["column_name"];

thank you....

Answer 6

As you can find on php.net , mysql_fetch_row has array for return type. You can echo the content of an array in a human readable format using this code:

echo "<pre>";
print_r($myArray);
echo "</pre>";

Also, a good practice will be to set aliases in your MySQL request, so you can use this alias as a key in the PHP code. In your case, you can use this:

$request = mysql_query("SELECT MAX(unique_id) AS maximumId FROM my_db.table");
$dataArray = mysql_fetch_row($request);
echo "http://yourdomain.com/display.php?urlid=" . $dataArray["maximumId"];

Hope this helps understand.