Reputation: 333
I am currently trying to run a query where the current value of a mysql table column increase itself by 1... Let me show this with mysql query example
$sql = mysql_query("UPDATE `table` SET quantity=quantity+1 WHERE id='$id'");
I am unable to do this in PDO prepared statement...
$sql = "UPDATE `table` SET quantity=:quants+1 WHERE id=:userid";
$sql_prep = $db->prepare($sql);
$sql_prep->bindParam(":quants", what will i write here??);
$sql_prep->bindParam(":userid", $id);
$sql_prep->execute();
Help needed..! Thanks
Upvotes: 5
Views: 108
Reputation: 41508
You don't need the to protect quantity
as you're just augmenting a value already in the db.
$sql = "UPDATE `table` SET quantity=quantity+1 WHERE id=:userid";
You can also drop the bind line for the :quants
$sql_prep = $db->prepare($sql);
// NOT NEEEDED --> $sql_prep->bindParam(":quants", what will i write here??);
$sql_prep->bindParam(":userid", $id);
$sql_prep->execute();
Prepared statements are for protecting data being inserted from the outside into your db via your query.
Upvotes: 0
Reputation: 2475
You don't need to pass that as a parameter, just do:
$sql = "UPDATE `table` SET quantity=quantity+1 WHERE id=:userid";
$sql_prep = $db->prepare($sql);
$sql_prep->bindParam(":userid", $id);
$sql_prep->execute();
Upvotes: 3