INNER JOIN if table 1 has 2 rows matching in table 2 - mysql

Question

I don't exactly know how to word this question correctly, so I'll start with the data because I think it will make more sense that way.
Starting with these two tables:
Table 1:
user_id | equipment_id
------ | ------
1 | 2
1 | 3
1 | 6
2 | 2
2 | 6
Table 2:
equipment_id | exercise_id
------ | ------
2 | 1
3 | 2
6 | 2
I would like to create this third table:
Table 3:
user_id | exercise_id
------ | ------
1 | 1
1 | 2
2 | 1
It seems like a simple INNER JOIN to get the data, but I'm running into trouble with the second row. I only want that row to show up if user_id 1 has both pieces of equipment listed in Table 2. If either piece of equipment is missing, I don't want the data inserted as shown by user_id 2. I also want to make sure I don't get two instances of user_id 1 for each piece of equipment.
This is the code I have so far:
INSERT INTO Table3 (user_id, exercise_id)
SELECT user_id, exercise_id
FROM Table1
INNER JOIN Table2
ON Table2.equipment_id = Table1.equipment_id
The result I get is this with the rows that need to be removed indicated:
Table 3:
user_id | exercise_id
------ | ------
1 | 1
1 | 2
1 | 2 <--- duplicate of row above
2 | 1
2 | 2 <--- user 2 doesn't have equipment 3, so shouldn't be included
Any help on limiting the results would be greatly appreciated. Thank you!

Answer 1

If I understand correctly, you want to retrieve all the exercises for a user where all the equipment required for that exercise is "available" to the user. I've put some code over at rextester.com/AYRE74108. The important part of that looks like this:
select distinct
t1.user_id,
t2.exercise_id
from
table_1 t1
JOIN table_2 t2 ON
t1.equipment_id = t2.equipment_id
where
not exists
(select 1
from
table_2 t2b
where
t2b.exercise_id = t2.exercise_id
AND not exists (select 1
from
table_1 t1b
where
t2b.equipment_id = t1b.equipment_id
AND t1.user_id = t1b.user_id)
)
To explain the logic: I begin with the standard join and distinct. But then I require that there NOT EXIST any piece of equipment required for the exercise such that that user/equipment combination does NOT EXIST. This is equivalent to saying the user has to have "available" (listed in table 1) all the equipment required for the exercise.
Or schematically: "ALL X are Y" === "NO X is such that Not Y".

Answer 2

I feel that the last row of your output should not be 2 | 2 but 1 | 2.
Also using distinct will ensure that there will be no duplicate rows.
SELECT DISTINCT user_id, exercise_id
FROM Table1
INNER JOIN Table2
ON Table2.equipment_id = Table1.equipment_id
Edit - The mistake in the question threw me off. This should work.
SELECT user_id, table2.exercise_id , sum(table2.equipment_id), sum(b.equipment_id)
FROM Table1
INNER JOIN Table2
ON Table2.equipment_id = Table1.equipment_id
inner join table2 as b
on table2.exercise_id = b.exercise_id
group by user_id, table2.exercise_id
having sum(table2.equipment_id)= sum(b.equipment_id)