Do you put the beginTransaction(); before or within the `try` block

Question

Should I do

$dbh->beginTransaction();
try{

Or

try{
  $dbh->beginTransaction();

Answer 1

It doesn't really matter, it will run the code indifferent of it's position. But you want to put the rollback() in the catch, and with that setup it's not readable if you put begin outside.

I would vote for inside the try.

Answer 2

It probably doesn't really matter. However, it's better to place the beginTransaction outside the try. When the beginTransaction fails, it should not execute the rollback.

Answer 3

add it inside the try/catch block, so you can catch any PDOException:

try {
    $dbh->beginTransaction();    // start transaction
    $stmt = $dbh->query($query); // run your query
    $dbh->commit();              // commit
} catch(PDOException $ex) {      // if exception, catch it
    $dbh->rollBack();            // rollback query
    echo $ex->getMessage();      // echo exception message
}