PHP preg_match模式是主题的子串

Question

I want to test if an input is of the type 1234567 (7 digits). I use

preg_match($pattern,$subject);

where

$pattern = '/^[0-9]{7}$/';

However I get 1 for the case where the subject is

L-8987765

Which I do not want. How can I overcome this?

   function isDocid($documento_id)
      {
       $subject = pg_escape_literal($documento_id);
       $pattern1 = '/^[0-9]{7}$/';

            if (preg_match($pattern1, $subject) === 1) 
            {
            return 1;
            }
            else
            {
            return 0;
            }}

$test_carta = isDocid('L-8987765');
echo('<p> ja existe docid   '. $test_carta  .'</p>');

I am expecting: ja existe docid 0

Answer 1

From the documentation (italics are mine):

pg_escape_literal() escapes a literal for querying the PostgreSQL database. It returns an escaped literal in the PostgreSQL format. pg_escape_literal() adds quotes before and after data.

In other words, you were never going to get a positive result from your regular expression check because of the quotes in the way. Don't use database escapes until you are ready to insert data into a database query. Or, better yet, don't insert a PHP variable into a database query – use prepared statements instead.

function isDocid($documento_id)
{
   return (preg_match('/^[0-9]{7}$/', $documento_id) === 1) ? 1 : 0;
}

$test_carta = isDocid('L-8987765');
echo('<p> ja existe docid   '. $test_carta  .'</p>');