Fetch data with PHP and MySQL of a “text” column with special characters on it

Question

I've a MySQL database that has this definition on one of its tables (theTable)

CREATE  TABLE `theDatabase`.`theTable` (
  `id` INT NOT NULL AUTO_INCREMENT ,
  `thecolumn` TEXT NOT NULL ,
  PRIMARY KEY (`id`) );

I'm trying this with PHP:

/*File executeSelect.php*/
mysql_connect("theServer","theUser","thePassword") or die(mysql_error());
mysql_select_db("theDatabase") or die (mysql_error());
$q = mysql_query($_REQUEST['query']);
while($e = mysql_fetch_assoc($q))
    $output[] = $e;
print(json_encode($output));
mysql_close();

If I do a executeSelect.php?query=select * from theTable , the information shown for the column thecolumn is NULL if thecolumn has special characters. I've thecolumn defined as text because I need to store large texts on it (500~1000 letters).

For example, a executeSelect.php?query=select * from theTable with id=1;thecolumn=asdf in theTable works OK, but the same executeSelect with id=1;thecolumn=ásdf in theTable gives NULL for thecolumn .

I've tried to execute the same query using the MySQL console and it works OK. I'm using Apache 2.4 and PHP 5.3.

What I'm misshing here that my php code doesn't retrieve data from text columns of MySQL in a right way?

Answer 1

我强烈建议不要这样做，因为这种方法很容易遭受SQL注入攻击

Answer 2

Should the code not be:

while($e = mysql_fetch_assoc($q))
    $output[] = $e['thecolumn'];
print(json_encode($output));
mysql_close();

I would not recommend this method, and would recommend using PDO also

Answer 3

After 2 years, it bothers me that there is no answer in this question that solves my issue.

As pointed by Mike W in the comments of the question, the issue was with encoding in the sql client.

If using MySQLi, something like described in PHP: mysqli::set_charset - Manual can be used.

In my scenario, it was just a matter of doing a simple $mysqli->set_charset("utf8") right after opening the connection.