I'm currently working on a proyect on cakephp 2.0 where i need to insert multiple users to a sql server database.
I need to make a rollback if something fails, but not necessarilly if the stored procedure failed, but if something within the php file logic fails throws an exception to make the rollback.
The code works like this:
try {
...$this->db->beginTransaction();//The connection to the DB is already on.
foreach($users as $user){
//some logic
if(something) {
throw new Exception('blah blah');
}
$query = $this->sqlsrv->prepare('storedProcedure1');
//bind parameters
if(!$query->execute()) {
throw new Exception('blah blah');
}
//some logic...
if(something) {
throw new Exception('blah blah');
}
$query = $this->sqlsrv->prepare('storedProcedure2');
bind parameters
if(!$query->execute()) {
throw new Exception('blah blah');
}
}
$this->db->commit();
}
catch (Exception $e){
$this->db->rollBack();
}
I dont know if something like this may be possible, the functions return true, but the succesfull inserts from the stored procedures are still there, and i would like to tollback all of those even when they were succesfull.
Related
I have a PHP psql query. I am doing try catch to prevent Duplicates. When I ran the script I can see it's inserting something into my DB. But when I check my DB it's empty.
foreach($data as $n){
$query = $psql->pdo_prepared("INSERT INTO students(id,email,address,phone)VALUES".myFunction($array);
}
and I have a PHP class to handle the exception:
public function pdo_prepared($query,array){
try{
// some logic
}
catch(EXCEPTION $e){
//empty
}
}
The reason why I am doing try catch is to catch duplicates and ignore it. If I throw an exception in my catch block my insert statement won't execute because my current data contains duplicates.
i have the following code:
$new_models = DB::transaction(function () use ($supplier, $address, $addressDetail) {
$new_supplier = $this->setNewSupplier($supplier);
$new_address = $this->setNewAddress($address);
$new_addressDetail = $this->setNewAddressDetail($addressDetail,$new_address->id);
$this->syncSupplierAddress($new_supplier->id,$new_address->id);
$this->updateControlAp($new_supplier->supplier_id);
return [$new_supplier, $new_address, $new_addressDetail];
});
The set methods are basically creating the models object with save() at the end;
Now this works perfectly fine if 2nd...nth fails BUT NOT if the first one fails.
If $this->setNewSupplier($supplier);
fails than i get
"PDOException in Connection.php line 541:
There is no active transaction"
Am i doing something wrong here ? Also if i comment $this->rollBack(); from the catch in vendor Connection.php it actually gives me the SQL error. Important part here is that this isn't working only if first save() fails
PS. I am using PostgreSQL not MySQL but i don't think its related
There are different ways to make transactions in Laravel, another one could be this:
...
$new_models = [];
try {
DB::beginTransaction();
$new_supplier = $this->setNewSupplier($supplier);
$new_address = $this->setNewAddress($address);
$new_addressDetail = $this->setNewAddressDetail($addressDetail,$new_address->id);
$this->syncSupplierAddress($new_supplier->id,$new_address->id);
$this->updateControlAp($new_supplier->supplier_id);
$new_models = [$new_supplier, $new_address, $new_addressDetail];
DB::commit();
} catch(\Exception $e) {
DB::rollback();
// Handle Error
}
...
I am connecting to MySQL through PDO with Zend\Db from ZF2. How can I report the last errorInfo()?
Here's what I have:
$sqlWriter = new Sql($this->getAdapter());
$insert = $sqlWriter->insert('table_name')->columns(array_keys($data))->values($data);
$stmt = $sqlWriter->prepareStatementForSqlObject($insert);
try {
$stmt->execute();
$object->id = $this->getAdapter()->driver->getLastGeneratedValue();
} catch (\Exception $e) {
//
// HOW CAN I display errorInfo() here?
//
throw new Exception\Exception('Unable to insert record...');
}
I have tried calling methods on the adapter, driver, statement, platform, result, etc... But all to no avail...
EDIT: I found that I can get the info I am looking for by posting the following at the top of the catch block:
$pdoException = $e->getPrevious();
var_dump($pdoException);
I'll leave the question open however since it would be good to know how to execute PDO::errorInfo() directly.
I can't get my head around WHEN to throw and catch exceptions for when I call functions from classes.
Please imagine that my QuizMaker class looks like this:
// Define exceptions for use in class
private class CreateQuizException extends Exception {}
private class InsertQuizException extends Exception {}
class QuizMaker()
{
// Define the items in my quiz object
$quiz_id = null;
$quiz_name = null;
// Function to create a quiz record in the database
function CreateQuizInDatabase()
{
try
{
$create_quiz = // Code to insert quiz
if (!$create_quiz)
{
// There was an error creating record in the database
throw new CreateQuizException("Failed inserting record");
}
else
{
// Return true, the quiz was created successfully
return true;
}
}
catch (CreateQuizException $create_quiz_exception)
{
// There was an error creating the quiz in the database
return false;
}
}
function InsertQuestions()
{
try
{
$insert_quiz = // Code to insert quiz
if (!$insert_quiz)
{
// There was an error creating record in the database
throw new CreateQuizException("Failed inserting quiz in to database");
}
else
{
// Success inserting quiz, return true
return true;
}
}
catch (InsertQuizException $insert_exception)
{
// Error inserting question
return false;
}
}
}
... and using this code, I use the class to create a new quiz in the database
class QuizMakerException extends Exception {}
try
{
// Create a blank new quiz maker object
$quiz_object = new QuizMaker();
// Set the quiz non-question variables
$quiz_object->quiz_name = $_POST['quiz_name'];
$quiz_object->quiz_intro = $_POST['quiz_intro'];
//... and so on ...
// Create the quiz record in the database if it is not already set
$quiz_object->CreateQuizRecord();
// Insert the quiz in to the database
$quiz_object->InsertQuestions();
}
catch (QuizMakerException $quiz_maker_error)
{
// I want to handle any errors from these functions here
}
For this piece of code, I want to call a QuizMakerException if any of the functions don't perform what I want them to (at the moment they return TRUE or FALSE).
What is the correct way to go about catching when any of the functions in this code does not perform what I want them to? At the moment they simply return TRUE or FALSE.
Do I really have to put lots of if/else statements between calling each function, I thought that was the whole point in exceptions, they simply halt the execution of further statements within the try/catch?
Do I throw a QuizMakerException from within the catch of my functions?
What is the right thing to do?
Help!
Well typically in the function which throws the exception, say your InsertQuestions method, you don't want to catch any exceptions, you want to throw them or let ones occurring to "bubble up". Then your "controller" code can make the determination of how to handle the exception.
If your goal here is to halt if CreateQuizRecord fails I would wrap CreateQuizRecord and InsertQuestions each in their own try block.
One advantage of exceptions is they can tell you more than a simple bool pass/fail. Either extending your base exception into things like "Invalid_Parameter" and testing for specific exceptions or -less ideally- inferring from properties of the exception. You can nest your catch blocks to handle exceptions individually.
Do I throw a QuizMakerException from within the catch of my functions?
Yes. Typically your code under // Code to insert quiz would itself return an exception. Say if the Model failed to insert it might be raising a database exception. In which case you can let that database exception bubble up, or do what you sort of doing now and catch it simply to in turn throw another exception (kinda dumbs down your exceptions in a way, doing that though).
Do I really have to put lots of if/else statements between calling each function, I thought that was the whole point in exceptions, they simply halt the execution of further statements within the try/catch?
I look at it like this, each call which throws an exception and is followed by a subsequent call which depends on this one not throwing any exceptions, should be wrapped in a try block. Assuming you want to handle it gracefully, if you simply want it to error out and halt just don't handle the exception. You'll get an error and stack trace. Sometimes that is desirable.
You might want to change the structure a bit. Your class QuizMaker can become:
<?php
// Define exceptions for use in class
public class CreateQuizException extends Exception {}
public class InsertQuizException extends Exception {}
class QuizMaker()
{
// Define the items in my quiz object
$quiz_id = null;
$quiz_name = null;
// Function to create a quiz record in the database
function CreateQuizInDatabase()
{
try
{
$create_quiz = // Code to insert quiz
if (!$create_quiz)
{
// There was an error creating record in the database
throw new CreateQuizException("Failed inserting record");
}
else
{
// Return true, the quiz was created successfully
return true;
}
}
catch (Exception $create_quiz_exception)
{
// There was an error creating the quiz in the database
throw new CreateQuizException(
"Failed inserting record " .
$create_quiz_exception->getMessage()
);
}
}
function InsertQuestions()
{
try
{
$insert_quiz = // Code to insert quiz
if (!$insert_quiz)
{
// There was an error creating record in the database
throw new InsertQuizException("Failed inserting quiz in to database");
}
else
{
// Success inserting quiz, return true
return true;
}
}
catch (Exception $insert_exception)
{
// Error inserting question
throw new InsertQuizException(
"Failed inserting quiz in to database " .
$create_quiz_exception->getMessage()
);
}
}
}
Effectively, if you cannot insert the record correctly, you throw an Insert exception. If anything goes wrong with that block of code, you catch it and throw again an Insert exception. Same goes with the Create function (or any other ones you might have).
In the main block of code you can have:
try
{
// Create a blank new quiz maker object
$quiz_object = new QuizMaker();
// Set the quiz non-question variables
$quiz_object->quiz_name = $_POST['quiz_name'];
$quiz_object->quiz_intro = $_POST['quiz_intro'];
//... and so on ...
// Create the quiz record in the database if it is not already set
$quiz_object->CreateQuizRecord();
// Insert the quiz in to the database
$quiz_object->InsertQuestions();
}
catch (InsertQuizException $insert_exception)
{
// Insert error
}
catch (CreateQuizException $create_quiz_exception)
{
// Create error
}
catch (Exception $quiz_maker_error)
{
// Any other error
}
If you don't want to have the multiple catch block there, just keep the catch(Exception) one and then check in it the type of each exception thrown to specify the actions taken from there.
HTH
The best thing to do is to not have to thhrow exceptions in the first place.
Exceptions are thrown when the program crashes and they are not made to handle wrong output.
If your function returns anything (even its the wrong thing) it doesn't need an exception.
To answer your question, if it's necessaryto use a lot of ifs/elses then you must use them.
I am trying to implement transactions to Kohana but it seems to be not so easy as in Spring/Java.
So far I found this code to try but I don't know how to replace the part (no errors)
DB::query('START TRANSACTION');
// sql queries with query builder..
if (no errors)
DB::query('COMMIT');
else
DB::query('ROLLBACK');
How do I make the if clause?
Normally transactions are handled as such:
DB::query('START TRANSACTION');
try {
//do something
DB::query('COMMIT');
} catch (Exception $e) {
DB::query('ROLLBACK');
}
What this means is if everything succeeds within the try block, great. If any part of it fails then it won't reach the commit and will jump to the catch block, which contains the rollback. You can add more error handling within the catch if you wish, even throw a new exception of your own or throw the same exception you caught.
Just wrap everything in a try/catch block:
DB::query('START TRANSACTION');
try {
// sql queries with query builder..
DB::query('COMMIT');
} catch (Database_Exception $e) {
DB::query('ROLLBACK');
}
DB errors are converted to exceptions:
DB::query('START TRANSACTION');
try {
// sql queries with query builder..
DB::query('COMMIT');
}
catch($e)
{
$this->template->body = new View('db_error');
$this->template->body->error = 'An error occurred ...';
DB::query('ROLLBACK');
}
If you're using Kohana 3:
$db = Database::instance();
$db->begin();
try
{
// Do your queries here
$db->commit();
}
catch (Database_Exception $e)
{
$db->rollback();
}