Sequelize: select models with a given number of matching children - mysql

Question

In my schema, User hasMany GameSession, GameSession hasMany Game.
For a particular user, I'm trying to select the most recent game session which has three games, each of which has a non-null score.
This comment looks like it does almost exactly what I want, but it's not working for me. It suggests this code:
ModelA.findAll({
include: [ModelB],
having: 'count(ModelB.id) > 0'
});
I think the above comment might be out of date, because unless I wrap the having clause in an array I get Error: where: "raw query" has been removed, please use where ["raw query", [replacements]].
So I have this JS:
user.getGameSessions({
include: [
{
model: models.Game,
where: {
score: {
$ne: null
}
}
}
],
having: ['count(Games.id) = 3'],
order: [['updatedAt', 'DESC']],
limit: 1
}).then(function(gameSessions) {
res.json(gameSessions);
});
And this is the query it is making:
SELECT
`GameSession`.*,
`Games`.`id` AS `Games.id`,
...
FROM (
SELECT
`GameSession`.`id`,
...
`GameSession`.`UserId`
FROM `GameSessions` AS `GameSession`
WHERE `GameSession`.`UserId` = 33 AND (
SELECT `GameSessionId`
FROM `Games` AS `Game`
WHERE (
`Game`.`GameSessionId` = `GameSession`.`id`
AND `Game`.`score` IS NOT NULL
)
LIMIT 1
) IS NOT NULL
HAVING count(Games.id) = 3
ORDER BY `GameSession`.`updatedAt` DESC
LIMIT 1
) AS `GameSession`
INNER JOIN `Games` AS `Games`
ON `GameSession`.`id` = `Games`.`GameSessionId`
AND `Games`.`score` IS NOT NULL
ORDER BY `GameSession`.`updatedAt` DESC;
But running this gives the following error: SequelizeDatabaseError: ER_BAD_FIELD_ERROR: Unknown column 'Games.id' in 'having clause'. I've also tried using singular Game.id in the having clause, since I'm not always certain when to use the plural and when to use the singular, and I get a similar error.
What am I doing wrong? How can I make this work?

Answer 1

Is it possible to limit an include?
Currently no. I think there's a feature request open
for it (although i couldn't find it with a cursory search. It's not
trivial to implement since it requires a join on a subquery.

Answer 2

I think because MySQL is case sensitive your Games.id is Games.Id or Games.ID.
If I were you to save yourself some grief in the future, just make every table and column uppercase or all lower case. Don't do camel casing or things like that! It becomes really hard to debug.
So your code here is probably:
having: 'count(Games.id) = 3',
should be:
having: 'count(Games.Id) = 3',
Edit:
Have you tried putting backticks around your count? Like this:
having: 'count(`Games`.`id`) = 3',