SQL not exist issue - sql

Question

Having a bit of trouble dealing with not exist clause in a query.
I have three tables:
Meal
no_meal integer
type_meal varchar(255)
Consumed
no_meal integer
designation varchar(255)
quantity integer
Food
designation varchar(255)
quantity integer
type varchar(255)
Quantity in food is quantity stored and quantity in consumed is consumed quantity so, they will differ and thus natural inner join won't cut it.
Type of food can be 'drink' 'meat' 'fish' and so on.
Type of meal can be 'Breakfast' 'Lunch' 'Dinner'
I want a query that will tell me the drinks that have been consumed in all types of meals.
I've been toggling and testing code but can't get it right. At the moment I'm trying this:
SELECT Consumed.designation
FROM Consumed
WHERE NOT EXISTS
(SELECT type_meal
FROM Consumed, Food, Meal
WHERE Consumed.designation = Food.designation
AND Consumed.no_meal = Meal.no_meal
AND type = 'Drink'
ORDER BY Food.designation)
EXCEPT
(SELECT type_meal
FROM Meal);
How the hell do I get it right?
Thanks for input.
EDIT:
I'll add some data in order to make it clearer.
Food
Steak 100 Meat
Water 200 Drink
Coca cola 300 Drink
Meal
0001 Breakfast
0002 Lunch
0003 Dinner
Consumed
0001 Water 50
0002 Steak 20
0001 Coca cola 20
0003 Water 5
0002 Water 15
Now, I want to know which drink has been consumed in every meal, which will only give water.
Hope I cleared some minds about the problem

Answer 1

Twist your mind a little bit, and think with double negatives ....
I want [...] the drinks that have been consumed in all types of meals.
You want all drinks for which there are NO meal types for which that drink is NOT part of the meal type:
select distinct f.designation
from food f
where
type = 'Drink' and
not exists (
select *
from meal m1
where not exists (
select *
from meal m2
join consumed c on c.no_meal = m2.no_meal
where
m1.no_meal = m2.no_meal and
c.designation = f.designation
)
)
This is called relational division.

Answer 2

Now I understand what you want...
SELECT designation
FROM Food
WHERE designation IN (
SELECT designation
FROM Consumed
GROUP BY designation
HAVING Count(DISTINCT no_meal) = (
SELECT Count(*) FROM Meal
)
)
WHERE type = 'Drink'

Answer 3

I want a query that will tell me the drinks that have been consumed in all types of meals.
Your edit did clear things up. Note that following query will not work if the combination Designation, Typein Consumedis not unique but I'm guessing it will be.
SELECT
c.Designation
FROM
(SELECT
c.Designation
FROM
Consumed c
INNER JOIN
Meal m ON m.no_meal = c.no_meal
GROUP BY
c.Designation
HAVING
COUNT(*) = (SELECT COUNT(*) FROM Meal)) c
INNER JOIN
Food f ON f.Designation = c.Designation
WHERE
f.Type = 'Drink'

Answer 4

select *
from food f inner join
consumed c_1 on c_1.designation = f.designation
where type='Drink' and
not exists -- to filter out drinks that are not a part of all the meals
(select 1
from consumed c_2 inner join
meal m_1 on m_1.no_meal = c_2.no_meal
where c_1.no_meal = c2.no_meal and
c_1.designation = c2.designation and
not exists (select 1
from meal m_2
where m_1.no_meal = m_2.no_meal))

Answer 5

I want a query that will tell me the drinks that have been consumed in all types of meals.
Here is the model structure and insertions you suggested:
USE SqlTests
GO
CREATE TABLE Meal (
no_meal int
, type_meal nvarchar(255)
)
GO
insert into Meal (no_meal, type_meal)
values (1, N'Breakfast')
GO
insert into Meal (no_meal, type_meal)
values(2, N'Lunch')
GO
insert into Meal (no_meal, type_meal)
values(3, N'Dinner')
GO
CREATE TABLE Consumed (
no_meal int
, designation nvarchar(255)
, quantity int
)
GO
insert into Consumed (no_meal, designation, quantity)
values (1, N'Water', 50)
GO
insert into Consumed (no_meal, designation, quantity)
values (2, N'Steak', 20)
GO
insert into Consumed (no_meal, designation, quantity)
values (1, N'Coca cola', 20)
GO
insert into Consumed (no_meal, designation, quantity)
values(3, N'Water', 5)
GO
insert into Consumed (no_meal, designation, quantity)
values(2, N'Water', 15)
GO
CREATE TABLE Food (
designation nvarchar(255)
, quantity int
, [type] nvarchar(255)
)
GO
insert into Food (designation, quantity, [type])
values (N'Water', 200, N'Drink')
GO
insert into Food (designation, quantity, [type])
values (N'Steak', 100, N'Meat')
GO
insert into Food (designation, quantity, [type])
values (N'Coca cola', 200, N'Drink')
GO
Then, selecting with the proposed SELECT:
select c.designation
from Consumed c
inner join Meal m on m.no_meal = c.no_meal
inner join Food f on f.designation = c.designation and f.[type] LIKE N'Drink'
group by c.designation
having COUNT(c.designation) = (select COUNT(type_meal) from Meal)
Returns (at least on my database engine (SQL Server Express 2005)
Water
Is my information data correct?