How do I use QueryBuilder with andWhere for json - symfony

Question

please I am just new to querybuilder and precisely I don't know how to work with json object in a where clause. I would appreciate your swift assistance.
"post_id": 1
"post": ""
"author": [{"id": 2, "email": "example#example.com"}, {"id": 3, "email": "example2#example.com"}]
"post_id": 2
"post": ""
"author": [{"id": 4, "email": "example#example.com"}, {"id": 9, "email": "example2#example.com"}]
I want to query the table Post where the author->id is current_user. I have tried all I can. I have installed composer require scienta/doctrine-json-functions
When I ran it, I got
"An exception occurred while executing a query: SQLSTATE[42883]: Undefined function: 7 ERROR: operator does not exist: json = unknown\nLINE 1: ... w0_ WHERE json_extract_path(w0_.author, $1) = $2 ORDER...\n ^\nHINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.",
I am out of ideas.
private function addWhere(QueryBuilder $queryBuilder, string $resourceClass): void
{
if (WorkshopSession::class !== $resourceClass || $this->security->isGranted('ROLE_ADMIN') || null === $user = $this->security->getUser()) {
return;
}
$rootAlias = $queryBuilder->getRootAliases()[0];
$queryBuilder->andWhere("JSON_EXTRACT_PATH(o.author, :id) = :current_user");
$queryBuilder->setParameter('id', 'o.id');
$queryBuilder->setParameter('current_user', $user->getId());
}
I am using api-platform and using doctrine extensions. Database Server - postgreSQL

Answer 1

First thing you need to do, is to switch option to jsonb that would help you traverse the json tree easily without putting yourself in a box.
select * from post where author #> '[{"id": "2"}]';
Running this in your traditional sql should work, then convert this to DQL. This may be tricky as there is no '#>' in DQL but you can take advantage of custom DQL User Defined Function. I recommend doing this instead of installing a third party library that would add a layer of abstraction and complexity with versioning issue (deprecation).
As you can see below, we make use of FunctionNode, SqlWalker, Lexer and Parser.
use Doctrine\ORM\Query\AST\Functions\FunctionNode;
use Doctrine\ORM\Query\SqlWalker;
use Doctrine\ORM\Query\AST\Node;
use Doctrine\ORM\Query\Parser;
use Doctrine\ORM\Query\Lexer;
use function sprintf;
class JsonContains extends FunctionNode
{
/** #var Node */
/** #psalm-suppress all */
private $expr1;
/** #var Node */
/** #psalm-suppress all */
private $expr2;
public function parse(Parser $parser) : void
{
$parser->match(Lexer::T_IDENTIFIER);
$parser->match(Lexer::T_OPEN_PARENTHESIS);
$this->expr1 = $parser->StringPrimary();
$parser->match(Lexer::T_COMMA);
$this->expr2 = $parser->StringPrimary();
$parser->match(Lexer::T_CLOSE_PARENTHESIS);
}
public function getSql(SqlWalker $sqlWalker) : string
{
return sprintf(
'(%s #> %s)',
$this->expr1->dispatch($sqlWalker),
$this->expr2->dispatch($sqlWalker)
);
}
}
One you have defined this, you can register it. Symfony 5 up suggests to use doctrine.yaml. You can register it as follows
dql:
string_functions:
JSON_CONTAINS: App\Doctrine\Extension\Functions\DQL\UDF\JsonContains
Then in your extensions, you can simply use it.
$queryBuilder->andWhere("JSON_CONTAINS(".$rootAlias .".author, :current_user) = true");
$queryBuilder->setParameter('current_user', json_encode([['id' => $user->getId()]]));
This may definitely help others going through it.
Cheers!