I have values I've added to my session that I'd like to pass into an query as follows:
$eventTypeID = $this->session->userdata('eventtypeID');
$this->session->unset_userdata('eventtypeID');
$venueCityID = $this->session->userdata('venuecityID');
$this->session->unset_userdata('venuecityID');
echo json_encode($this->event_model->getSearchEvents($eventTypeID, $venueCityID));
The issue I'm running into is that last line (echo json_encode...) will not run when the prior variables are extracted/unset. If I comment out the variables, and run simply:
echo json_encode($this->event_model->getSearchEventsAll());
Then all works well. Can someone tell my why json_encode doesn't seem to play well with sessions and how I may be able to get this to work? Thanks!
EDITED
After much frustration, it now appears the issue may not be with the session, but is instead with outputting my query:
$this->db->_compile_select();
$q = $this->db->get();
echo $this->db->last_query();
All used to work fine, and I was able to "intercept" the query to see what was being called, but now when using _compile & last_query, nothing happens????
Run json_last_error() to see if any errors were encountered encoding the data. See the example on the docs page for proper usage:
http://www.php.net/manual/en/function.json-last-error.php
We're not certain what $this->event_model->getSearchEvents($eventTypeID, $venueCityID) returns VS $this->event_model->getSearchEvents(), but there should definitely not be any problems related to the use of variables.
As always, try var_dump() on the output (try before decoding) and see what the differences are between the two return values of the function. You might even be encountering an error within the function itself that's stopping execution - make sure error_reporting() is on full-blast.
Related
I have the following code attempting to truncate a table. The Joomla documentation makes me believe this will work, but it does not. What am I missing?
$db = JFactory::getDbo();
truncate_query = $db->getQuery(true);
//$truncate_query = 'TRUNCATE ' . $db->quoteName('#__mytable');
$truncate_query->truncateTable($db->quoteName('#__mytable'));
$db->setQuery($truncate_query);
echo $truncate_query;
exit();
If I use the line that is commented out to manually generate the SQL, it does work. The reason I am still looking to use the truncateTable function is that I am trying to include the truncation in a transaction. When I use the manual statement, the table is still truncated even if another part of the transaction fails, which is annoying since the other statements rely on data that is truncated, so if the table is emptied when it shouldn't be there is no data left to run the transaction again. Very annoying!
Here's how you call/execute your truncation query:
JFactory::getDbo()->truncateTable('#__mytable');
And now some more details...
Here is the method's code block in the Joomla source code:
public function truncateTable($table)
{
$this->setQuery('TRUNCATE TABLE ' . $this->quoteName($table));
$this->execute();
}
As you can see the truncateTable() method expects a tablename as a string for its sole parameter; you are offering a backtick-wrapped string -- but the method already offers the backtick-wrapping service. (Even if you strip your backticks off, your approach will not be successful.)
The setQuery() and execute() calls are already inside the method, so you don't need to create a new query object nor execute anything manually.
There is no return in the method, so the default null is returned -- ergo, your $truncate_query becomes null. When you try to execute(null), you get nothing -- not even an error message.
If you want to know how many rows were removed, you will need to run a SELECT query before hand to count the rows.
If you want to be sure that there are no remaining rows of data, you'll need to call a SELECT and check for zero rows of data.
Here is my answer (with different wording) on your JSX question.
This is my PHP SQL statement and it's returning false while var dumping
$sql = $dbh->prepare('INSERT INTO users(full_name, e_mail, username, password) VALUES (:fullname, :email, :username, :password)');
$result = $sql->execute(array(
':fullname' => $_GET['fullname'],
':email' => $_GET['email'],
':username' => $_GET['username'],
':password' => $password_hash));
TL;DR
Always have set PDO::ATTR_ERRMODE to PDO::ERRMODE_EXCEPTION in your PDO connection code. It will let the database tell you what the actual problem is, be it with query, server, database or whatever. Also, make sure you can see PHP errors in general.
Always replace every PHP variable in the SQL query with a question mark, and execute the query using prepared statement. It will help to avoid syntax errors of all sorts.
Explanation
Sometimes your PDO code produces an error like Call to a member function execute() or similar. Or even without any error but the query doesn't work all the same. It means that your query failed to execute.
Every time a query fails, MySQL has an error message that explains the reason. Unfortunately, by default such errors are not transferred to PHP, and all you have is a silence or a cryptic error message mentioned above. Hence it is very important to configure PHP and PDO to report you MySQL errors. And once you get the error message, it will be a no-brainer to fix the issue.
In order to get the detailed information about the problem, either put the following line in your code right after connect
$dbh->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
(where $dbh is the name of your PDO instance variable) or - better - add this parameter as a connection option. After that all database errors will be translated into PDO exceptions which, if left alone, would act just as regular PHP errors.
After getting the error message, you have to read and comprehend it. It sounds too obvious, but learners often overlook the meaning of the error message. Yet most of time it explains the problem pretty straightforward:
Say, if it says that a particular table doesn't exist, you have to check spelling, typos, letter case. Also you have to make sure that your PHP script connects to a correct database
Or, if it says there is an error in the SQL syntax, then you have to examine your SQL. And the problem spot is right before the query part cited in the error message.
You have to also trust the error message. If it says that number of tokens doesn't match the number of bound variables then it is so. Same goes for absent tables or columns. Given the choice, whether it's your own mistake or the error message is wrong, always stick to the former. Again it sounds condescending, but hundreds of questions on this very site prove this advice extremely useful.
Note that in order to see PDO errors, you have to be able to see PHP errors in general. To do so, you have to configure PHP depends on the site environment:
on a development server it is very handy to have errors right on the screen, for which displaying errors have to be turned on:
error_reporting(E_ALL);
ini_set('display_errors',1);
while on a live site, all errors have to be logged, but never shown to the client. For this, configure PHP this way:
error_reporting(E_ALL);
ini_set('display_errors', 0);
ini_set('log_errors', 1);
Note that error_reporting should be set to E_ALL all the time.
Also note that despite the common delusion, no try-catch have to be used for the error reporting. PHP will report you PDO errors already, and in a way better form. An uncaught exception is very good for development, yet if you want to show a customized error page, still don't use try catch for this, but just set a custom error handler. In a nutshell, you don't have to treat PDO errors as something special but regard them as any other error in your code.
P.S.
Sometimes there is no error but no results either. Then it means, there is no data to match your criteria. So you have to admit this fact, even if you can swear the data and the criteria are all right. They are not. You have to check them again. I've short answer that would help you to pinpoint the matching issue, Having issue with matching rows in the database using PDO. Just follow this instruction, and the linked tutorial step by step and either have your problem solved or have an answerable question for Stack Overflow.
Some time ago I had the same problem of not seeing any error messages from mysql. After a research it turned out that the problem has got nothing to do with PHP itself, but with mysql server configuration. The default value of the variable lc_messages_dir pointed to non existing directory. After adding a line in mysqld.cnf, then restarted the mysql server, and finally I was able to see the error messages. For me the following was the right one:
lc_messages_dir=/usr/share/mysql
It is described in the mysql reference manual: https://dev.mysql.com/doc/refman/5.7/en/error-message-language.html
I am creating a simple member system using MySQL, and have stumbled onto a problem.
The issue is that I am using the correct SQL query to search the column Username, and find Administrator, but however my query isn't finding anything.
I have searched the internet for a solution (with many results taking my back to Stack Overflow), but however have not found anything.
The query that I am using is:
SELECT * FROM members WHERE Username = "Administrator"
Which looks find from my end, but however does not return any results:
Am I doing something wrong here?
I am new to MySQL & PHP, so if something is obviously wrong with what I'm doing here, please tell me nicely, and please don't 'flame'.
Edit:
When attempting to run this query though PHP, I get:
Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in /home/crysisor/public_html/checklogin.php on line 22
The above code confirms that something is wrong...
Relevant code:
$user = mysqli_real_escape_string($sqli, $_POST['user']);
$pass = mysqli_real_escape_string($sqli, $_POST['pass']);
if ($user && $pass) {
$checkuser= mysqli_num_rows(mysqli_query($sqli, "SELECT * FROM users WHERE Username='".$user."'"));
I have a few hints which may help you resolve your problem.
Make the query itself a PHP variable, and echo it. Then copy and paste the echoed result into phpMyAdmin.
Use single quotes for query variables. The query itself should be in double quotes.
Unrelated: the password looks short. It shouldn't be stored in plain text.
I running a Mysql Query to select some data, Sometimes i get a error called
mysql_fetch_assoc() expects parameter 1 to be resource, boolean given
when i executed this following code,
$result = $this->db->execute($sql);
for ($i = 0; $data[$i + 1] = mysql_fetch_assoc($result); $i++);
array_pop($data);
how do i optimize this coding to prevent any errors ?
is there anything wrong with it ? should i ignore this error ?
That means that the query is buggy, whyever, most likely because you construct it using components from sources which you do not really check enough. A buggy statement throws an error (since no result can be computed). That error is returned as false instead of a mysql result ressource. Since you do not check if the query succeeded but blindly try to retrieve details from the result, you get this second error.
So there are four things you have to invest into:
you should always check if a query succeeded at all:
enclose your query into a conditional: if (FALSE!==($result=$this->db->execute($sql))) and only retrieve from the result ressource if that condition resolves to true.
make sure you really (really!) check all input data you use to construct your query. Checking here also means to encode and escape it correctly, also see point 4. for this.
in cases like this it is important to analyze what exactly it is that is going wrong. There is little sense in guessing what might be going wrong. So in addition to checking if the query succeeded at all (1.) you should also take a look at the error message mysql throws if this is not the case. Use the method mysql_error() for this. It is well documented just as every other function too.
you should rework your code and migrate from phps old, long deprecated mysql extension to either mysqli or PDO. Both are php extensions that offer more security against constructing buggy statements. Read about "prepared statements" and "parameter binding" for this.
Using CI for the first time and i'm smashing my head with this seemingly simple issue. My query wont insert the record.
In an attempt to debug a possible problem, the insert code has been simplified but i'm still getting no joy.
Essentially, i'm using;
$data = array('post_post' => $this->input->post('ask_question'));
$this->db->insert('posts', $data);
I'm getting no errors (although that possibly due to disabling them in config/database.php due to another CI related trauma :-$ )
Ive used
echo print $this->db->last_query();
to get the generated query, shown as below:
INSERT INTO `posts` (`post_post`) VALUES ('some text')
I have pasted this query into phpMyAdmin, it inserts no problem. Ive even tried using $this->db->query() to run the outputted query above 'manually' but again, the record will not insert.
The scheme of the DB table 'posts' is simply two columns, post_id & post_post.
Please, any pointers on whats going on here would be greatly appreciated...thanks
OK..Solved, after much a messing with CI.
Got it to work by setting persistant connection to false.
$db['default']['pconnect'] = FALSE;
sigh
Things generally look ok, everything you have said suggests that it should work. My first instinct would be to check that what you're inserting is compatible with your SQL field.
Just a cool CI feature; I'd suggest you take a look at the CI Database Transaction class. Transactions allow you to wrap your query/queries inside a transaction, which can be rolled back on failure, and can also make error handling easier:
$this->db->trans_start();
$this->db->query('INSERT INTO posts ...etc ');
$this->db->trans_complete();
if ($this->db->trans_status() === FALSE)
{
// generate an error... or use the log_message() function to log your error
}
Alternatively, one thing you can do is put your Insert SQL statement into $this->db->query(your_query_here), instead of calling insert. There is a CI Query feature called Query Binding which will also auto-escape your passed data array.
Let me know how it goes, and hope this helps!