在Phalcon Framework中不存在与Phql一起使用

Question

I'm trying to write a short query with phql . I'm selecting everything from one table and have a where clause declaring that another table can't have a record connected to this table. Here's the raw sql query that works fine when run against my db, which is Mysql.

select * from application a
where not exists (select distinct 1 from preapproval p where p.application_id = a.id)

So on to trying to write this in phql , I've been trying different things, but here's what I've ended up with.

Note: If I run this without the where clause it works, selecting all records from the 'application' table.

$manager = \Phalcon\DI::getDefault()->getShared("modelsManager");

$data = $manager
    ->createBuilder()
    ->from(['a' => '\Models\Application'])
    ->where('not exists (select distinct 1 from [\Models\Preapproval] where [\Models\Preapproval].application_id = a.id)')
    ->getQuery()
    ->execute();

The exception being thrown is:

Syntax error, unexpected token SELECT, near to ' distinct 1 from [\Models\Preapproval] where [\Models\Preapproval].application_id = a.id)', when parsing: SELECT [a].* FROM [\Models\Application] AS [a] WHERE not exists (select distinct 1 from [\Models\Preapproval] where [\Models\Preapproval].application_id = a.id) (190)

So on to the question, how do I write a where not exists clause in phql ?

Answer 1

Unfortunately Phalcon is not always able to parse complex queries using PhQL query builder.

However in this particular case you can do a leftJoin with condition:

/** @var ModelManager $manager */
$manager = \Phalcon\DI::getDefault()->getShared("modelsManager");
$data = $manager->createBuilder()
    ->columns('\Models\Application.*')
    ->from('\Models\Application')
    ->leftJoin('\Models\Preapproval', '\Models\Preapproval.application_id = \Models\Application.id')
    ->andWhere('\Models\Preapproval.id IS NULL')
    ->getQuery()
    ->execute();

This may or may not have a negative or positive impact on performance depending on your database index cardinality.

Answer 2

I had a similar problem. You can either use raw sql , left joins (in my case i had to use many 'join ON' conditions) or you can try this