actions-test/src/api/helper.ts

import { alias, eq, count, select, naturalJoin, innerJoinOn } from "dblang";
import { accounts, db, roomMembers, rooms } from "../sys/db.js";

export const isRoomFull = async (roomID: number) => {
    let currentCount = alias(
        select([count(roomMembers.roomMemberID)], roomMembers)
            .where(eq(roomMembers.roomID, roomID)),
        "currentCount"
    ) as any;
    let maxCount = alias(
        select([accounts.maxUsersPerRoom],
            innerJoinOn(accounts, rooms, eq(accounts.accID, rooms.owner)))
            .where(eq(rooms.roomID, roomID)),
        "maxCount"
    ) as any;
    let req = await select([currentCount, maxCount], null)
        .query(db);
    return req[0][currentCount] >= req[0][maxCount];
};