I am trying to extract from my php laravel some data like this:
$x = Carbon::now()->timestamp;
$data=Notifications->where('happened_at','>',$x)
->where('id_user',Auth::user()->getAuthIdentifier());
If I enter this sql statement in my oracle database directly it works perfectly:
select * from notifications where happened_at > '10-06-2017 00:11:12,000000000';
^ this returns correct, however in my php laravel it doesn't return the good rows(returns all the rows from the database)
Later Edit: The where is the problem, I just want to compare the timestamp location in my DB('happened_at') with the current time...I don't know how though
Let's break down your model call code.
// first, you retrieve all notifications and assign them to $data
$data = Notifications::all()
// then, you try to start a new query
->where('happened_at','>',$x)
// then, you continue the new query
->where('id_user',Auth::user()->getAuthIdentifier())
// and finally, you finish the call
;
So basically, you already get all rows at the beginning, and then you try to start building a query that you never execute. (But you can't, since all() returns a collection.)
Remove the all() and finish up with ->get() at the end, and it should work. (Although I don't know anything about Oracle timestamps.)
Related
I have this code:
$fee = sys_fee::where('payment', '=', 'Paid')->get();
$totalFee = $fee->sum('amount');
Can anyone tell me, whether traverses database for both of these lines above or does it only go to database once in the first line?
In simple, does the following line, execute another query on database or does it only work with the array?
$totalFee = $fee->sum('amount');
My current understanding is that it doesn't execute another query on database.
Your $fee is an objection of Collection, the sum() method doesn't make SQL calls, instead it goes through all the elements of that collection.
https://laravel.com/docs/5.7/collections#method-sum
Trying to make a little Search feature for a user, so he can type in a date on a webpage made with HTML/PHP, and see which people in the db have registered as member on or after (a date). My user inputs the date in format 2015-10-01. This gets sent to a PHP page with a jqxGrid on it, populated with member details of members conforming to my query on the MySQL database (using PDO).
The query uses the operator >= on a string passed as (for example) "2015-10-01" in the WHERE clause, so I am using STR_TO_DATE to make the comparison work:
WHERE `lastUpdated` >= STR_TO_DATE( ? , '%Y-%m-%d');
With PDO, the ? later gets bound to the date (which was passed in as a string).
The db column for registration date is in DATETIME format, and in the db values look like: "2015-10-12 17:12:52".
My query returns an empty array every time, - and this after many hours of trying every conceivable permutation of date format, both in the MySQL statement and on the page that prepares the data for populating the grid.
Can someone show me what's wrong here?
Thanks!!
SP
Make it
WHERE `lastUpdated` > ?
and check your data and stuff.
Basically, you should never touch PDO until you get raw SQL to work.
okay, so here is the PDO version that works - passing in ? instead of the date:
function getJSONAllMembersByDate($PDOdbObject, $regDate)
{
try
{
$membersByDateSQL = "SELECT `id`, `name_first`, `name_last`, `organization`,`email`, `phone`,`source`,`comments`,`language_id`, `lastUpdated` FROM `member` WHERE lastUpdated>=?";//'$regDate'
$get=$PDOdbObject->prepare($membersByDateSQL);
$get->execute(array($regDate));
$rows = $get->fetchAll(PDO::FETCH_ASSOC);
$json=json_encode($rows);
return $json;
}
The fact that it works proves there were other errors in the file containing the jqxwidget (the version before I posted here). I certainly tried about a million different things to get this working.
I don't know if this counts as an answer, but at least it WORKS! There are so many variables in this problem - json, jqxgrid, pdo ... not forgetting that there are several ways to use PDO. I probably had several errors in different places.
(#apokryfos, the STR_TO_DATE was indeed unnecessary.)
In the end, this is what works:
In the PHP page containing the jqxGrid, the url sent to the server is:
url: 'my-json-responses.php?fct=getJSONAllMembersByDate®Date=<?php echo $fromDate ?>'
This $fromDate comes from the $_POST when the user typed in a date (in the format 2015-10-01) on the input page. When the PHP page containing the jqxGrid loads, it does
$fromDate = $_POST['regDate'];
The url "transits" through the file my-json-reponses.php, which contains many functions. It finds the right one:
if ($_GET['fct'] == 'getJSONAllMembersByDate')
{
$result = getJSONAllMembersByDate($connectionObject, $_GET['regDate']);
echo $result;
}
The $result is called on the file that contains all my PDO database requests, including:
function getJSONAllMembersByDate($PDOdbObject, $regDate) { try
{
$membersByDateSQL = "SELECT `id`, `name_first`, `name_last`, `organization`,`email`, `phone`,`source`,`comments`,`language_id`, `lastUpdated` FROM `member` WHERE lastUpdated>='$regDate'";
$get=$PDOdbObject->query($membersByDateSQL);
$rows = $get->fetchAll(PDO::FETCH_ASSOC);
$json=json_encode($rows);
return $json;
}
catch (PDOException $e)
{
echo "There was a problem getting all members with this search query.";
echo $e->getMessage();
}}
Note that I couldn't make the version using "?" in the query work at all, hence passing in the variable $regDate directly, with single quotes around the variable just to make life interesting.
This returns a nice list of all my users as of 2015-10-01 - but is presumably still open to MySQL injection attacks ...
But after this marathon of debugging I am happy enough for now. (All improvements welcomed, naturally!)
SP
In CakePHP3, there is a ORM that helps with building queries.
From the documentation, I can see that
$query = $articles->find(); // build a query that has not run yet
$query->where(['id' => 1]); // Return the same query object
So in this case, I want the string
WHERE `articles`.`id` = 1
After much googling, I found out that there is a way to return just the where clause of a query object.
$query->where(['id' => 1])->clause('where'); // Return the where clause in the form of a QueryExpression
More googling leads me to find out how to get the QueryExpression to spit out string representation
$query->where(['id' => 1])->clause('where')->sql($valueBinder); // Return the where clause in string format
Here is my problem. I don't know what the $valueBinder is supposed to look like. I don't know how to initialize it.
I am also happy not to use ValueBinder as long as I can get the where clause in string format using CakePHP 3 ORM and in the right SQL dialect. Please assume I am using MySQL.
Please advise.
EDIT
I tried to use $query->valueBinder() as the $valueBinder.
It is empty and does not contain the associated c:0 to the value 1.
To directly answer your question, you can get the SQL for any clause this way:
$binder = new \Cake\ORM\ValueBinder();
$query->clause('where')->sql($binder);
That will return the SQL with the correct placeholders, not with the values to be used. The values live in the $binder variable and are used for statement objects.
As I can see, you only wanted to preserve the internal structure of the where clause to pass it to another query in a different request. Your solution is fine, but I'd like to add that you can also encode a full conditions tree from an existing query:
$where = serialize($query->clause('where'));
$anotherQuery->where(unserialize($where)); // A query in another request
In any case, you need to be careful with what you are unserializing as taking it directly from user input will certainly lead to security problems.
You can choose to omit this param if you like. Please see http://api.cakephp.org/3.0/class-Cake.Database.Query.html#_sql
In addition, you can use the Query member function traverse($visitor, $parts) to isolate the where clause. $visitor is a function that takes a value and a clause. You define the behavior of $visitor. $parts is an array of clause names. I suggest passing array('where') into this param.
My workaround is that I store the conditions in json string format.
Using the same example, what I do is
$data['conditions'] = json_encode(['Articles.id' => 1]); // encode into JSON string
$this->DynamicRules->patchEntity($dynamicRule, $data); // use in edit action of DynamicRulesController
then when I need to reuse the conditions, I do:
$articlesTable = TableRegistry::get('Articles');
$query = $articlesTable->find(); // new query for Articles
$rule = json_decode($dynamicRule->conditions, true); // get back the conditions in associative array format
$query->where($rule); // re-assign the conditions back
This got me what I ultimately wanted.
When I execute a PDO statement, internally a result set is stored, and I can use ->fetch() to get a row from the result.
If I wanted to convert the entire result to an array, I could do ->fetchAll().
With Laravel, in the Query Builder docs, I only see a way to get an array result from executing the query.
// example query, ~30,000 rows
$scores = DB::table("highscores")
->select("player_id", "score")
->orderBy("score", "desc")
->get();
var_dump($scores);
// array of 30,000 items...
// unbelievable ...
Is there any way to get a result set from Query Builder like PDO would return? Or am I forced to wait for Query Builder to build an entire array before it returns a value ?
Perhaps some sort of ->lazyGet(), or ->getCursor() ?
If this is the case, I can't help but see Query Builder is an extremely short-sighted tool. Imagine a query that selects 30,000 rows. With PDO I can step through row by row, one ->fetch() at a time, and handle the data with very little additional memory consumption.
Laravel Query Builder on the other hand? "Memory management, huh? It's fine, just load 30,000 rows into one big array!"
PS yes, I know I can use ->skip() and ->take() to offset and limit the result set. In most cases, this would work fine, as presenting a user with 30,000 rows is not even usable. If I want to generate large reports, I can see PHP running out of memory easily.
After #deczo pointed out an undocumented function ->chunk(), I dug around in the source code a bit. What I found is that ->chunk() is a convenience wrapper around multiplying my query into several queries queries but automatically populating the ->step($m)->take($n) parameters. If I wanted to build my own iterator, using ->chunk with my data set, I'd end up with 30,000 queries on my DB instead of 1.
This doesn't really help, too, because ->chunk() takes a callback which forces me to couple my looping logic at the time I'm building the query. Even if the function was defined somewhere else, the query is going to happen in the controller, which should have little interest in the intricacies of my View or Presenter.
Digging a little further, I found that all Query Builder queries inevitably pass through \Illuminate\Database\Connection#run.
// https://github.com/laravel/framework/blob/3d1b38557afe0d09326d0b5a9ff6b5705bc67d29/src/Illuminate/Database/Connection.php#L262-L284
/**
* Run a select statement against the database.
*
* #param string $query
* #param array $bindings
* #return array
*/
public function select($query, $bindings = array())
{
return $this->run($query, $bindings, function($me, $query, $bindings)
{
if ($me->pretending()) return array();
// For select statements, we'll simply execute the query and return an array
// of the database result set. Each element in the array will be a single
// row from the database table, and will either be an array or objects.
$statement = $me->getReadPdo()->prepare($query);
$statement->execute($me->prepareBindings($bindings));
return $statement->fetchAll($me->getFetchMode());
});
}
See that nasty $statement->fetchAll near the bottom ?
That means arrays for everyone, always and forever; your wishes and dreams abstracted away into an unusable tool Laravel Query Builder.
I can't express the valley of my depression right now.
One thing I will say though is that the Laravel source code was at least organized and formatted nicely. Now let's get some good code in there!
Use chunk:
DB::table('highscores')
->select(...)
->orderBy(...)
->chunk($rowsNumber, function ($portion) {
foreach ($portion as $row) { // do whatever you like }
});
Obviously returned result will be just the same as calling get, so:
$portion; // array of stdObjects
// and for Eloquent models:
Model::chunk(100, function ($portion) {
$portion; // Collection of Models
});
Here is a way to use the laravel query builder for making the query, but to then use the underlying pdo fetch to loop over the record set which I believe will solve your problem - running one query and looping the record set so you don't run out of memory on 30k records.
This approach will use all the config stuff you setup in laravel so you don't have to config pdo separately.
You could also abstract out a method to make this easy to use that takes in the query builder object, and returns the record set (executed pdo statement), which you would then while loop over as below.
$qb = DB::table("highscores")
->select("player_id", "score")
->orderBy("score", "desc");
$connection = $qb->getConnection();
$pdo = $connection->getPdo();
$query = $qb->toSql();
$bindings = $qb->getBindings();
$statement = $pdo->prepare($query);
$statement->execute($bindings);
while ($row = $statement->fetch($connection->getFetchMode()))
{
// do stuff with $row
}
I'm building a script using PHP and MySQL to compare a certain live page against older versions of it - i'm doing it by md5 hashing it and comparing it to the latest version.
Now i'm trying to pull the latest known hash of a certain page using the following:
SELECT latest_hash FROM tracked_sites WHERE domain = 'domain.com
Which shows me the actual contant of latest_hash for a certain "domain.com"
Now i'm trying to put it in a valid variable so i can compare it using the following:
$latestmd5_sql=(mysqli_query($con,"SELECT latest_hash FROM tracked_sites WHERE domain = 'domain.com'"));
Now, thinking i have the actual content of the database i'm trying to compare it with
if ((md5(file_get_contents("https://domain.com/page.html")))==$latestmd5_sql)
BUT, for some reason i get False as answer.
I've tried to print out the $latestmd5_sql var using echo or print_r but it seems to be empty or empty array, i'm a bit puzzled as to what i'm doing wrong and would love to get ideas.
In your provided code, $latestmd5_sql will be a resource, not the value in the database.
You'll need to "fetch" the data from the resource in order to compare values.
Here's an example to illustrate the workflow from sql code to php variable:
// your sql
$sql="SELECT latest_hash FROM tracked_sites WHERE domain = 'domain.com'";
// the query (returns a resource)
$query = mysqli_query($con,$sql);
// fetch the resulting data (this is the part you're missing)
$result=mysqli_fetch_assoc($query);
// take a look at the data (for debugging purposes)
echo"DATA:<pre>".print_r($result,true)."</pre>";
// compare
if ((md5(file_get_contents("https://domain.com/page.html")))==$result['latest_hash']) {
echo"<p>Match</p>";
} else {
echo"<p>No Match</p>";
}