PDO rollback if affected rows are 0 - php

Question

I create a PDO Database class to manage connections to the db, query's and transactions. I want to execute all the query's in one transaction, so if one throw an error, the others rollback.
Firs i create the update, delete or insert statement to run, and add the query with a function.
public function addQuery($entity)
{
$this->stack[] = $entity;
}
Then i commit all the querys in the array:
public function commit()
{
self::beginTransaction();
try {
foreach ($this->stack as $entity) {
$entity->execute();
}
self::commitTransaction();
return true;
} catch (Exception $e) {
self::rollbackTransaction();
return false;
}
}
This are the functions that i use:
protected function beginTransaction()
{
$this->dbo->beginTransaction();
}
protected function commitTransaction()
{
$this->dbo->commit();
}
protected function rollbackTransaction()
{
$this->dbo->rollBack();
}
I tried making two updates. The firs that will update a row, and the second will affect 0 rows. But my function don't roll back the firs update.

Answer 1

In your code, you catch an error with catch (Exception $e) then execute a rollback.
If you want to consider an SQL statement that affects 0 rows an error then you could do the following:
public function commit()
{
self::beginTransaction();
try {
foreach ($this->stack as $entity) {
$entity->execute();
# If the statement affected 0 rows, then throw an error
# that will trigger a rollback
if ( $entity->rowCount() == 0 ) {
throw new \Exception("0 rows affected.");
}
}
self::commitTransaction();
return true;
} catch (Exception $e) {
self::rollbackTransaction();
return false;
}
}
Cautionary note This could have very unexpected consequences as certain statements (like SELECT) affect 0 rows and then would trigger a ROLLBACK.
Hope this help!