带有$ i和$ _POST值的SQL循环

Question

I am trying to loop through a number of results from a form, but can't get it quite right.

  for ($i=1;$i<$total;i++)
    {
     mysql_query("INSERT INTO MYSQL(value1,value2,value3) VALUES('{$i}','{$_POST['$iH']}', '{$_POST['$iA']}'");
    }

I want $_POST['$iH'] to be the same as $_POST['1H'],$_POST['2H'], $_POST['3H'] etc.

Answer 1

Like so:

for ($i = 1; $i < $total; $i++) { // <--- You had a typo here
   $sql  = "INSERT INTO MYSQL(value1,value2,value3) ";
   $sql .= "VALUES('{$i}','" . $_POST[$i . 'H'] . "', '" . $_POST[$i . 'A'] . "')";
   mysql_query($sql);
}

But, two big problems.

Multiple queries

Boy, what a waste! Dispatch one instead:

$rows = Array();
for ($i = 1; $i < $total; $i++) {
   $rows[] = "('{$i}','" . $_POST[$i . 'H'] . "', '" . $_POST[$i . 'A'] . "')";
}

$sql  = "INSERT INTO MYSQL(value1,value2,value3) VALUES('" . implode("','", $rows) . "')";
mysql_query($sql);

SQL injection

It continues to baffle me how, in 2011, people are still not getting this.

If you're going to insist upon using the ancient mysql API (not even the OO version?!) rather than PDO, get into the habit of sanitising your inputs:

$rows = Array();
for ($i = 1; $i < $total; $i++) {
   $rows[] = "('{$i}'," . 
             "'" . mysql_escape_string($_POST[$i . 'H']) . "'," .
             "'" . mysql_escape_string($_POST[$i . 'A']) . "')";
}

$sql = "INSERT INTO MYSQL(value1,value2,value3) VALUES('" . implode("','", $rows) . "')";
mysql_query($sql);

OK, so without multi-query support in your API it's unlikely to cause you significant grief here, but it can do in authentication routines. Just get used to scripting properly in this regard.