sequelize: Incorrect SELECT query generation including "LIMIT" clause and "M:N" association with "where" clause returns unexpected results

Hello,

I’ve come across a bug with query generation which include limiting results with including belongsToMany relation containing WHERE clause.

I made executable script to demonstrate this behavior as they are cases when generated query might return expected result if query and data in database are in specific state.

if you investigate the file the following are queries generated for particular demonstration cases:

“Test 1”: Works

    Student.findAndCount({
        offset: 6,
        order: [["id", "DESC"]],
        include: [
            {
                model: Teacher,
                as: 'teachers',
                where: {
                    id: {$in: [3, 2]}
                }
            }
        ]
    });

SELECT "student"."id", "student"."age", "student"."name",
"student"."created_at", "student"."updated_at", "teachers"."id" AS
"teachers.id", "teachers"."age" AS "teachers.age", "teachers"."name" AS
"teachers.name", "teachers"."created_at" AS "teachers.created_at",
"teachers"."updated_at" AS "teachers.updated_at",
"teachers.student_teacher"."id" AS "teachers.student_teacher.id",
"teachers.student_teacher"."teacher_id" AS
"teachers.student_teacher.teacher_id", "teachers.student_teacher"."student_id"
AS "teachers.student_teacher.student_id"
FROM "student" AS "student"
INNER JOIN (
    "student_teacher" AS "teachers.student_teacher"
    INNER JOIN "teacher" AS "teachers"
    ON "teachers"."id" = "teachers.student_teacher"."teacher_id"
)
ON "student"."id"  = "teachers.student_teacher"."student_id"
AND "teachers"."id" IN (3, 2)
ORDER BY "student"."id" DESC OFFSET 6;

“Test 2”: Bug - Wrong query generated… but this case returns expected result by “coincidence”

    Student.findAndCount({
        limit: 5,
        offset: 6,
        order: [["id", "DESC"]],
        include: [
            {
                model: Teacher,
                as: 'teachers',
                where: {
                    id: {$in: [3, 2]}
                }
            }
        ]
    });

SELECT "student".*, "teachers"."id" AS "teachers.id", "teachers"."age" AS
"teachers.age", "teachers"."name" AS "teachers.name", "teachers"."created_at"
AS "teachers.created_at", "teachers"."updated_at" AS "teachers.updated_at",
"teachers.student_teacher"."id" AS "teachers.student_teacher.id",
"teachers.student_teacher"."teacher_id" AS
"teachers.student_teacher.teacher_id", "teachers.student_teacher"."student_id"
AS "teachers.student_teacher.student_id"
FROM (
    SELECT "student"."id", "student"."age", "student"."name",
    "student"."created_at", "student"."updated_at"
    FROM "student" AS "student"
    WHERE (
        SELECT "student_teacher"."id"
        FROM "student_teacher" AS "student_teacher"
        INNER JOIN "teacher" AS "teacher"
        ON "student_teacher"."teacher_id" = "teacher"."id"
        WHERE ("student"."id" = "student_teacher"."student_id")
        LIMIT 1
    ) IS NOT NULL
    ORDER BY "student"."id" DESC LIMIT 5 OFFSET 6
) AS "student"
INNER JOIN (
    "student_teacher" AS "teachers.student_teacher"
    INNER JOIN "teacher" AS "teachers"
    ON "teachers"."id" = "teachers.student_teacher"."teacher_id"
)
ON "student"."id" = "teachers.student_teacher"."student_id"
AND "teachers"."id" IN (3, 2)
ORDER BY "student"."id" DESC;

“Test 3”: Bug - Wrong query - returns unexpected results

    Student.findAndCount({
        limit: 5,
        offset: 6,
        include: [
            {
                model: Teacher,
                as: 'teachers',
                where: {
                    id: {$in: [3, 2]}
                }
            }
        ]
    });

SELECT "student".*, "teachers"."id" AS "teachers.id", "teachers"."age" AS
"teachers.age", "teachers"."name" AS "teachers.name", "teachers"."created_at"
AS "teachers.created_at", "teachers"."updated_at" AS "teachers.updated_at",
"teachers.student_teacher"."id" AS "teachers.student_teacher.id",
"teachers.student_teacher"."teacher_id" AS
"teachers.student_teacher.teacher_id", "teachers.student_teacher"."student_id"
AS "teachers.student_teacher.student_id"
FROM (
    SELECT "student"."id", "student"."age", "student"."name",
    "student"."created_at", "student"."updated_at"
    FROM "student" AS "student"
    WHERE (
        SELECT "student_teacher"."id"
        FROM "student_teacher" AS "student_teacher"
        INNER JOIN "teacher" AS "teacher"
        ON "student_teacher"."teacher_id" = "teacher"."id"
        WHERE ("student"."id" = "student_teacher"."student_id")
        LIMIT 1
    ) IS NOT NULL LIMIT 5 OFFSET 6
) AS "student"
INNER JOIN (
    "student_teacher" AS "teachers.student_teacher"
    INNER JOIN "teacher" AS "teachers"
    ON "teachers"."id" = "teachers.student_teacher"."teacher_id"
)
ON "student"."id" = "teachers.student_teacher"."student_id"
AND "teachers"."id" IN (3, 2);

As I look at queries it seems it would be great if generated queries for test cases 2 and 3 would be the same as in 1 with LIMIT included at the end of query, wouldn’t it?

Thank you for your work!