Question mark operator in query - php

In my laravel 5 app, I'm using PostgreSQL's jsonb data type and it has ? operator.
But I can't get it work in my model, because laravel uses question marks as bindings.
Specifically, in whereRaw() method:
$query->whereRaw("jsonb_column ? 'a_key'")
How can I use question mark in my queries?

you can consider using the function call instead of operator.
First you should find out which function ? operator uses via following query on your PostgresSQL database:
SELECT oprname, oprcode FROM pg_operator WHERE oprname = '?'
on my development database it's jsonb_exists function,
then you can update your query as:
$query->whereRaw("jsonb_exists(jsonb_column, 'a_key')")
I hope it helps, happy coding.

Basically you have 2 options:
Getting your hand dirty by extending the current way Laravel's Query Builder implement whereRaw, otherwise stated doing it the hard way.
Send feature request to the Laravel team (ie asking them to extend all Query Builder component dealing with more PostgresQL specifics) and cross your fingers they will address it if you are patient enough.
Here are my takes for the [1.] option:
The namespace "Illuminate\Database\Query" is good for you:
You need particularly to delve into the following Laravel 5.0 source codes of interest:
Builder.php
Grammar.php
PostgresGrammar.php
Code fragments of interest:
whereRaw in Builder.php (excerpt):
/**
* Add a raw where clause to the query.
*
* #param string $sql
* #param array $bindings
* #param string $boolean
* #return $this
*/
public function whereRaw($sql, array $bindings = array(), $boolean = 'and')
{
$type = 'raw';
$this->wheres[] = compact('type', 'sql', 'boolean');
$this->addBinding($bindings, 'where');
return $this;
}
compileWheres in Grammar.php (excerpt):
/**
* Compile the "where" portions of the query.
*
* #param \Illuminate\Database\Query\Builder $query
* #return string
*/
protected function compileWheres(Builder $query)
{
$sql = array();
if (is_null($query->wheres)) return '';
// Each type of where clauses has its own compiler function which is responsible
// for actually creating the where clauses SQL. This helps keep the code nice
// and maintainable since each clause has a very small method that it uses.
foreach ($query->wheres as $where)
{
$method = "where{$where['type']}";
$sql[] = $where['boolean'].' '.$this->$method($query, $where);
}
// If we actually have some where clauses, we will strip off the first boolean
// operator, which is added by the query builders for convenience so we can
// avoid checking for the first clauses in each of the compilers methods.
if (count($sql) > 0)
{
$sql = implode(' ', $sql);
return 'where '.$this->removeLeadingBoolean($sql);
}
return '';
}
$operators array in PostgresGrammar.php (excerpt):
/**
* All of the available clause operators.
*
* #var array
*/
protected $operators = array(
'=', '<', '>', '<=', '>=', '<>', '!=',
'like', 'not like', 'between', 'ilike',
'&', '|', '#', '<<', '>>',
);
notice that ? is not a valid operator ;-)
Specialized PostgreSQL protected methods in PostgresGrammar.php (excerpt):
/**
* Compile the additional where clauses for updates with joins.
*
* #param \Illuminate\Database\Query\Builder $query
* #return string
*/
protected function compileUpdateWheres(Builder $query)
{
$baseWhere = $this->compileWheres($query);
if ( ! isset($query->joins)) return $baseWhere;
// Once we compile the join constraints, we will either use them as the where
// clause or append them to the existing base where clauses. If we need to
// strip the leading boolean we will do so when using as the only where.
$joinWhere = $this->compileUpdateJoinWheres($query);
if (trim($baseWhere) == '')
{
return 'where '.$this->removeLeadingBoolean($joinWhere);
}
return $baseWhere.' '.$joinWhere;
}
/**
* Compile the "join" clauses for an update.
*
* #param \Illuminate\Database\Query\Builder $query
* #return string
*/
protected function compileUpdateJoinWheres(Builder $query)
{
$joinWheres = array();
// Here we will just loop through all of the join constraints and compile them
// all out then implode them. This should give us "where" like syntax after
// everything has been built and then we will join it to the real wheres.
foreach ($query->joins as $join)
{
foreach ($join->clauses as $clause)
{
$joinWheres[] = $this->compileJoinConstraint($clause);
}
}
return implode(' ', $joinWheres);
}
consider these as a sort of specialization of the compileWheres mentioned above, the remaining cases apart from the two (only 2!!!) specific ones are compiled using the parent class method (Illuminate\Database\Query\Grammars\Grammar).
Other recommended relevant resources
You may find valuable posts in this blog (SOFTonSOFA).
I particularly recommend:
Laravel Query Builder global scope – how to use custom Connection and Query Builder in Laravel 4, not in right version but shows how to extend the Query Builder.
Laravel 5 Eloquent Global Scope how-to, in Laravel 5.0 but orthogonal to your question yet instructive (right version, plumbing details).
Last but not the least, the Laravel documentation is the best place to grab more about its Architecture Foundations (Service Providers, Service Container, Facades and so on). Mastering it is handy to devise a robust extension of the framework.
Hopefully my input gives you enough hints for the possible extension point of the Laravel Query Builder offered and may it serve as a good starting point for you to write the PostgreSQL extension addressing the ?operator issue in whereRaw.
Please give back/share when done.

Try escaping it using a backslash, like this
SELECT * FROM table WHERE id = \?;

Related

Laravel: How to remove a specific 'where' clause from the Query Builder

I am fairly new to laravel and need to remove a 'where clause' from the Query Builder based on search options being selected or not.
My model contains the following already in a local scope:
$builder->where('users.active', '=', 'Yes');
and I need to override this in a specific search circumstance to either allow values of 'Yes' and 'No', or just remove the clause entirely. This must be done in a Trait and be suitable for multi uses/models.
I have actually got this to work by adding a new method in my SearchTrait that strips the query builder apart, removes the offending column and associated binding and returns the modified query builder.
$builder = static::removeWhere($builder, 'users.active');
This seems to work - but my question(s) are:
Is this a suitable solution, or is there something more elegant?
Are there any glaring issues with my solution?
Is there a better place for this / can I easily extend the 'builder'?
/**
* #param Builder $builder
* #param $whereColumn
* #return Builder
*/
public static function removeWhere(Builder $builder, $whereColumn)
{
$bindings = $builder->getQuery()->bindings['where'];
$wheres = $builder->getQuery()->wheres;
$whereKey = false;
foreach ($wheres as $key => $where) {
if ($where['column'] == $whereColumn) {
$whereKey = $key;
break;
}
}
if ($whereKey !== false) {
unset($bindings[$whereKey]);
unset($wheres[$whereKey]);
}
$builder->getQuery()->wheres = $wheres;
$builder->getQuery()->bindings['where'] = $bindings;
return $builder;
}

In Laravel Eloquent what is the difference between limit vs take?

In the documentation it shows the following:
To limit the number of results returned from the query, or to skip a given number of results in the query, you may use the skip and take methods:
$users = DB::table('users')->skip(10)->take(5)->get();
Alternatively, you may use the limit and offset methods:
$users = DB::table('users')
->offset(10)
->limit(5)
->get();
What are the differences between these two? Are there any differences in execution speed?
With the Query Builder, take() is just an alias for limit():
/**
* Alias to set the "limit" value of the query.
*
* #param int $value
* #return \Illuminate\Database\Query\Builder|static
*/
public function take($value)
{
return $this->limit($value);
}
NB This is not to be confused with take() on Collections.
limit only works for eloquent ORM or query builder objects, whereas take works for both collections and the ORM or Query Builder objects.
Model::get()->take(20); // Correct
Model::get()->limit(20); // Incorrect
Model::take(20)->get() // Correct
Model::limit(20)->get() // Correct
if take is used before get, it is the same as limit. If used after get, the action is performed by php itself.
that is
Model ::limit(10)->get() = Model ::take(10)->get()
and take to get
Model :: take(10)->get()
Launched through Query/Builder
public function take ($value)
{
return $this->limit($value);
}}
method to be starts.
Sql
select * from `table` where
`table`.`deleted_at` is null
limit 20
If used after get
Model :: get()->take(10);
Launched through Collection
public function take ($limit)
{
if ($limit<0) {
return $this->slice($limit, abs($limit));
}}
return $this->slice(0, $limit);
}}
method worked. and all the data is retrieved via sql and then $limit (10) are allocated via php
Sql
select * from `table` where
`table`.`deleted_at` is null
Limit works for eleqoent. Mostly used with offset
e.g
Model::offset(10)->limit(10)->get()
In the case above, it means get 10 elements(limit) starting from the 10th element onwards(offset).
Take is mostly used with collections but can also be used as an alias of limit for eloquent models

select random row for each category in array [duplicate]

Here is how I query my database for some words
$query = $qb->select('w')
->from('DbEntities\Entity\Word', 'w')
->where('w.indictionary = 0 AND w.frequency > 3')
->orderBy('w.frequency', 'DESC')
->getQuery()
->setMaxResults(100);
I'm using mysql and I'd like to get random rows that match the criteria, I would use order by rand() in my query.
I found this similar question which basically suggests since ORDER BY RAND is not supported in doctrine, you can randomize the primary key instead. However, this can't be done in my case because I have a search criteria and a where clause so that not every primary key will satisfy that condition.
I also found a code snippet that suggests you use the OFFSET to randomize the rows like this:
$userCount = Doctrine::getTable('User')
->createQuery()
->select('count(*)')
->fetchOne(array(), Doctrine::HYDRATE_NONE);
$user = Doctrine::getTable('User')
->createQuery()
->limit(1)
->offset(rand(0, $userCount[0] - 1))
->fetchOne();
I'm a little confused as to whether this will help me work around the lack of support for order by random in my case or not. I was not able to add offset after setMaxResult.
Any idea how this can be accomplished?
The Doctrine team is not willing to implement this feature.
There are several solutions to your problem, each having its own drawbacks:
Add a custom numeric function: see this DQL RAND() function
(might be slow if you have lots of matching rows)
Use a native query
(I personally try to avoid this solution, which I found hard to maintain)
Issue a raw SQL query first to get some IDs randomly, then use the DQL WHERE x.id IN(?) to load the associated objects, by passing the array of IDs as a parameter.
This solution involves two separate queries, but might give better performance than the first solution (other raw SQL techniques than ORDER BY RAND() exist, I won't detail them here, you'll find some good resources on this website).
Follow these steps:
Define a new class at your project as:
namespace My\Custom\Doctrine2\Function;
use Doctrine\ORM\Query\Lexer;
class Rand extends \Doctrine\ORM\Query\AST\Functions\FunctionNode
{
public function parse(\Doctrine\ORM\Query\Parser $parser)
{
$parser->match(Lexer::T_IDENTIFIER);
$parser->match(Lexer::T_OPEN_PARENTHESIS);
$parser->match(Lexer::T_CLOSE_PARENTHESIS);
}
public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
{
return 'RAND()';
}
}
Register the class config.yml:
doctrine:
orm:
dql:
numeric_functions:
Rand: My\Custom\Doctrine2\Function\Rand
Use it directly as:
$qb->addSelect('RAND() as HIDDEN rand')->orderBy('rand()'); //Missing curly brackets
In line with what Hassan Magdy Saad suggested, you can use the popular DoctrineExtensions library:
See mysql implementation here: https://github.com/beberlei/DoctrineExtensions/blob/master/src/Query/Mysql/Rand.php
# config.yml
doctrine:
orm:
dql:
numeric_functions:
rand: DoctrineExtensions\Query\Mysql\Rand
Tested in Doctrine ORM 2.6.x-dev, you can then actually do:
->orderBy('RAND()')
Or you could do this -->
$words = $em->getRepository('Entity\Word')->findAll();
shuffle($words);
Of course this would be very inefficient if you have many records so use with caution.
Why not to use repository?
<?php
namespace Project\ProductsBundle\Entity;
use Doctrine\ORM;
class ProductRepository extends ORM\EntityRepository
{
/**
* #param int $amount
* #return Product[]
*/
public function getRandomProducts($amount = 7)
{
return $this->getRandomProductsNativeQuery($amount)->getResult();
}
/**
* #param int $amount
* #return ORM\NativeQuery
*/
public function getRandomProductsNativeQuery($amount = 7)
{
# set entity name
$table = $this->getClassMetadata()
->getTableName();
# create rsm object
$rsm = new ORM\Query\ResultSetMapping();
$rsm->addEntityResult($this->getEntityName(), 'p');
$rsm->addFieldResult('p', 'id', 'id');
# make query
return $this->getEntityManager()->createNativeQuery("
SELECT p.id FROM {$table} p ORDER BY RAND() LIMIT 0, {$amount}
", $rsm);
}
}
For me, the most useful way was to create two arrays where i say order type and different properties of the Entity. For example:
$order = array_rand(array(
'DESC' => 'DESC',
'ASC' => 'ASC'
));
$column = array_rand(array(
'w.id' => 'w.id',
'w.date' => 'w.date',
'w.name' => 'w.name'
));
You could add more entries to array $column like criteria.
Afterwards, you can build your query with Doctrine adding $column and $order inside ->orderBy. For example:
$query = $qb->select('w')
->from('DbEntities\Entity\Word', 'w')
->where('w.indictionary = 0 AND w.frequency > 3')
->orderBy($column, $order)
->getQuery()
->setMaxResults(100);
This way improved the performance of my application. I hope this helps someone.
Shuffling can be done on the query (array) result, but shuffling does not pick randomly.
In order to pick randomly from an entity I prefer to do this in PHP, which might slow the random picking, but it allows me to keep control of testing what I am doing and makes eventual debugging easier.
The example below puts all IDs from the entity into an array, which I can then use to "random-treat" in php.
public function getRandomArt($nbSlotsOnPage)
{
$qbList=$this->createQueryBuilder('a');
// get all the relevant id's from the entity
$qbList ->select('a.id')
->where('a.publicate=true')
;
// $list is not a simple list of values, but an nested associative array
$list=$qbList->getQuery()->getScalarResult();
// get rid of the nested array from ScalarResult
$rawlist=array();
foreach ($list as $keyword=>$value)
{
// entity id's have to figure as keyword as array_rand() will pick only keywords - not values
$id=$value['id'];
$rawlist[$id]=null;
}
$total=min($nbSlotsOnPage,count($rawlist));
// pick only a few (i.e.$total)
$keylist=array_rand($rawlist,$total);
$qb=$this->createQueryBuilder('aw');
foreach ($keylist as $keyword=>$value)
{
$qb ->setParameter('keyword'.$keyword,$value)
->orWhere('aw.id = :keyword'.$keyword)
;
}
$result=$qb->getQuery()->getResult();
// if mixing the results is also required (could also be done by orderby rand();
shuffle($result);
return $result;
}
#Krzysztof's solution is IMHO best here, but RAND() is very slow on large queries, so i updated #Krysztof's solution to gives less "random" results, but they are still random enough. Inspired by this answer https://stackoverflow.com/a/4329492/839434.
namespace Project\ProductsBundle\Entity;
use Doctrine\ORM;
class ProductRepository extends ORM\EntityRepository
{
/**
* #param int $amount
* #return Product[]
*/
public function getRandomProducts($amount = 7)
{
return $this->getRandomProductsNativeQuery($amount)->getResult();
}
/**
* #param int $amount
* #return ORM\NativeQuery
*/
public function getRandomProductsNativeQuery($amount = 7)
{
# set entity name
$table = $this->getClassMetadata()
->getTableName();
# create rsm object
$rsm = new ORM\Query\ResultSetMapping();
$rsm->addEntityResult($this->getEntityName(), 'p');
$rsm->addFieldResult('p', 'id', 'id');
# sql query
$sql = "
SELECT * FROM {$table}
WHERE id >= FLOOR(1 + RAND()*(
SELECT MAX(id) FROM {$table})
)
LIMIT ?
";
# make query
return $this->getEntityManager()
->createNativeQuery($sql, $rsm)
->setParameter(1, $amount);
}
}
I hope this would help others:
$limit = $editForm->get('numberOfQuestions')->getData();
$sql = "Select * from question order by RAND() limit $limit";
$statement = $em->getConnection()->prepare($sql);
$statement->execute();
$questions = $statement->fetchAll();
Note here the table question is an AppBundle:Question Entity. Change the details accordingly. The number of questions is taken from the edit form, make sure to check the variable for the form builder and use accordingly.
First get the MAX value from DB table & then use this as offset in PHP i.e
$offset = mt_rand(1, $maxId)
I know this is an old question. But I used the following solution to get the random row.
Using an EntityRepository method:
public function findOneRandom()
{
$id_limits = $this->createQueryBuilder('entity')
->select('MIN(entity.id)', 'MAX(entity.id)')
->getQuery()
->getOneOrNullResult();
$random_possible_id = rand($id_limits[1], $id_limits[2]);
return $this->createQueryBuilder('entity')
->where('entity.id >= :random_id')
->setParameter('random_id', $random_possible_id)
->setMaxResults(1)
->getQuery()
->getOneOrNullResult();
}
Probably the easiest (but not necessarily the smartest) way to get a single object result ASAP would be implementing this in your Repository class:
public function findOneRandom()
{
$className = $this->getClassMetadata()->getName();
$counter = (int) $this->getEntityManager()->createQuery("SELECT COUNT(c) FROM {$className} c")->getSingleScalarResult();
return $this->getEntityManager()
->createQuery("SELECT ent FROM {$className} ent ORDER BY ent.id ASC")
->setMaxResults(1)
->setFirstResult(mt_rand(0, $counter - 1))
->getSingleResult()
;
}
Just add the following:
->orderBy('RAND()')

Escape raw SQL queries in Laravel 4

How does one go about escaping parameters passed to a raw query in Laravel 4? I expected something like DB::escape() (which rings a bell from Laravel 3) and also attempted DB::quote() (which I thought could be available through the PDO object)
$query = DB::select("SELECT * FROM users WHERE users.id = " . DB::escape($userId));
We can't use the select method with placeholders as the above is just a simplified example of what we are trying to achieve. We have a large custom query with a few nested select queries that cannot be adapted to the query builder.
What is the best approach to escaping something prior to inserting in Laravel 4?
EDIT:
I've just discovered that you can access the PDO object and use the quote function on it this way. Is this still the best approach, or is there an easier way to access this function?
DB::connection()->getPdo()->quote("string to quote");
You can quote your strings this way, through the DB facade.
DB::connection()->getPdo()->quote("string to quote");
I did put this answer in my question when I discovered it, however I've now put it in as an actual answer to make it easier for others to find.
$value = Input::get("userID");
$results = DB::select( DB::raw("SELECT * FROM users WHERE users.id = :value"), array(
'value' => $value,
));
More Details HERE
You may also try this, (Read Documentation)
$results = DB::select('SELECT * FROM users WHERE users.id = ?', array($userId));
Two answers here, that I use, have less verbose solutions built into the DB facade.
First, value quoting:
// From linked answer
DB::connection()->getPdo()->quote("string to quote");
// In the DB facade
DB::getPdo()->quote('string to quote');
Second, identifier quoting (table and column names):
// From linked answer
DB::table('x')->getGrammar()->wrap('table.column');
// In the DB facade
DB::getQueryGrammar()->wrap('table.column');
I found this question when looking for generic sql escaping in Laravel. What I actually needed though was table/column name escaping. So, for future reference:
/**
* Quotes database identifier, e.g. table name or column name.
* For instance:
* tablename -> `tablename`
* #param string $field
* #return string
*/
function db_quote_identifier($field) {
static $grammar = false;
if (!$grammar) {
$grammar = DB::table('x')->getGrammar(); // The table name doesn't matter.
}
return $grammar->wrap($field);
}
I'm using this in my helpers.php at Laravel 5:
if ( ! function_exists('esc_sql'))
{
function esc_sql($string)
{
return app('db')->getPdo()->quote($string);
}
}
Then I can use esc_sql function where I need to pergorm escaping for raw SQL queries.
Here's a fuller example, showing how to escape both values and columns and extend Laravel's querybuilder:
<?php
namespace App\Providers;
use Illuminate\Database\Query\Builder;
use Illuminate\Support\ServiceProvider;
class DatabaseQueryBuilderMacroProvider extends ServiceProvider {
public function register() {
Builder::macro('whereInSet', function($columnName, $value) {
/** #var \Illuminate\Database\Query\Grammars\Grammar $grammar */
$grammar = $this->getGrammar();
return $this->whereRaw('FIND_IN_SET(?,' . $grammar->wrap($columnName) . ')', [$value]);
});
}
}
PHP Heredoc
<?php
use Illuminate\Support\Facades\DB;
$sql = <<<SQL
WITH table1 AS(SELECT...
SQL;
$parameters = [1,2,3,...]
$table = DB::select($sql, $parameters);

Which database patterns (ORM, DAO, Active Record, etc.) to use for small/medium projects?

I writing real estate web site
with basic function for choosing and ordering realty.
It is small/simple project, but I want to write it in way,
so in future I, or other developers, can turn it into medium business app without rewriting it
from scratch.
So what kind of patterns could you advice me to use for dealing with database?
For now I have this:
class db_DBConnection
{
// basic singleton pattern here...
}
// primary class to be extende by other table DAOs
abstract class db_Table
{
protected $table;
protected $order_by;
/**
* Executes specified query with prepared statements
* returns statement object, which can fetch data.
*
* #param $sql - SQL query to execute
* #param $params - bind values to markers through associative arrays
*/
protected function executeQuery($sql, $params = null)
{
$dbh = db_DBConnection::getConnection();
$stmt = $dbh->prepare($sql);
// binds values to markers and executes query
$stmt->execute($params);
return $stmt;
}
/**
* #param id - id of row to retrieve from database
*
* It sends SQL query and id to executeQuery
* function returns associative array, representing
* database row.
*/
public function find($id)
{
$sql = 'SELECT * FROM ' . $this->table . ' WHERE id=:id LIMIT 1';
// bind id
$params = array( ':id' => $id );
// execute and return associative array
return $this->executeQuery($sql, $params)->fetch(PDO::FETCH_ASSOC);
}
public function findAll($quantity, $where)
{
// Returns array of
// associative arrays of table rows :)
// TODO: write this function
}
abstract protected function insert();
abstract protected function update();
abstract protected function delete();
// ...
The best way would be to use an ORM, like Doctrine. It might seem a little too much for smaller type project, but it pays off in a long run.
It is better to use standard ways of doing things, instead of reinventing your own.
Here is a list of ORMS from Wikipedia.
Also you need to evaluate your project, creating project freestyle might not be a very good idea. Other developers will have to learn your code and understand how it works, etc... It is better to use well know frameworks like Zend Framework, Symfony or CakePHP. You can also look into expandable CMS systems like Joomla and Drupal.

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