Mysql REGEX匹配查询

Question

What is the correct query to match string variable with MySQL field? For example:

$var_surname = $_POST['surname'];
$var_surname = strtolower($var_surname);

SELECT surname FROM tblname WHERE LOWER(surname) REGEX $var_surname
..........
..........

if($check > 0)
{
    Surname already exists
} 
else 
{
    Successful
}

Any help will be appreciated.

Answer 1

REGEX isn't a valid MySQL operator, it's REGEXP :

SELECT surname FROM tblname WHERE LOWER(surname) REGEXP '$var_surname';

However, REGEXP looks like it's overkill in this case -- the LIKE operator or a simple equality test should work fine:

SELECT surname FROM tblname WHERE LOWER(surname) LIKE '$var_surname';

Or:

SELECT surname FROM tblname WHERE LOWER(surname) = '$var_surname';

And please sanitize $var_surname before using it in your query -- use mysql_real_escape_string or Prepared Statements !

Answer 2

I don't understand, why are you using REGEX (should be REGEXP by the way) ? Just do

"SELECT surname FROM tblname WHERE LOWER(surname) = '$var_surname'"