How to create constraints that use expr() dynamically? - typo3-9.x

Question

A user can enter a letter range like "A-D", by which a query must find all records that start with any of those letters. What I eventually need is a constraints block that looks like this:
$constraints = [
$query->expr()->eq(
'composition.sys_language_uid',
$query->createNamedParameter($language, \PDO::PARAM_INT)
),
$query->expr()->orX(
$query->expr()->like(
'composition.title',
$query->createNamedParameter('A%')
),
$query->expr()->like(
'composition.title',
$query->createNamedParameter('B%')
),
$query->expr()->like(
'composition.title',
$query->createNamedParameter('C%')
),
$query->expr()->like(
'composition.title',
$query->createNamedParameter('D%')
)
)
];
which is a structure, that works well, when I use it as a test. So I know I need to strive for a solution like this.
But, of course, since the letters given are not fixed, but variable, the block within ->orX() needs to be calculated programmatically. This is, where my problem lies.
I tried this:
// A custom helper function that splits a letter range string like "A-D"
// and returns an array like ['A','B','C','D']
$compareLetters = Helper::returnItemOrListAsArray($letter, true);
}
// Create the query
$query = $allDbConnections['composition']->createQueryBuilder();
// Collect constraints
$addConstraints = [];
// Compare first letter against given compareLetters
foreach($compareLetters as $l) {
$addConstraints[] = $query->expr()->like(
'composition.title',
$query->createNamedParameter($l . '%')
);
}
Trying to insert the resulting array like this:
$constraints = [
$query->expr()->eq(
'composition.sys_language_uid',
$query->createNamedParameter($language, \PDO::PARAM_INT)
),
$query->expr()->orX(
implode(',', $addConstraints)
)
]
throws an exception:
Operand should contain 1 column(s)
Currently I have no idea, how to do this differently nor how to interpret the exception. Any hint would be most welcome!

Answer 1

Not sure whether it's a good approach, but I would try out range() function to generate the query, something like this:
<?php
$userInput = 'A-D';
list($start, $end) = explode('-', $userInput);
$selection = [];
foreach (range($start, $end) as $letter) {
$selection[] = $query->expr()->like(
'composition.title',
$query->createNamedParameter($letter . '%')
);
}
$constraints = [
$query->expr()->eq(
'composition.sys_language_uid',
$query->createNamedParameter($language, \PDO::PARAM_INT)
),
$query->expr()->orX(...$selection)
];
So more or less what you already did. Just you are not using the spread operator in your example when calling orX()