I have users table
ID NAME
1 John
2 Mike
3 Jack
and table with attributes and user IDs
USER ATTRIBUTE
1 1
1 2
2 4
I need to select all users with attribute 1 AND 2 (so, in this example user #1 John). Attributes can be more than two.
I'v tried
SELECT * FROM user u LEFT JOIN attributes a ON u.id = a.user
WHERE a.attribute = 1 AND a.attribute = 2
but of course it not working..
You will need to use a combination of IN() and GROUP BY ... HAVING to achieve this. Also no need for a join if all you need is user ID's. So something like:
SELECT user, COUNT(attribute) AS attribute_count
FROM attributes
WHERE attribute IN(...) /* include your set of attributes here */
GROUP BY user
HAVING attribute_count = ? /* include number equal to number of attribute ID's in IN() above */
If you need user id's and names you can simply join this record set derived from the query above as a filter to the users table:
SELECT user.id, user.name
FROM user
INNER JOIN
(
SELECT user, COUNT(attribute) AS attribute_count
FROM attributes
WHERE attribute IN(...) /* include your set of attributes here */
GROUP BY user
HAVING attribute_count = ? /* include number equal to number of attribute ID's in IN() above */
) AS filter
ON user.id = filter.user
having clause can be used with sum
SELECT u.id FROM user u
INNER JOIN attributes a ON u.id = a.user
group by u.id
having ( sum(case when attribute in (1,2) then 1 else 0 end) ) =2
You are looking for all users for whom EXIST attribute 1 and 2. One way to solve this - as the name suggests - is the EXISTS clause:
select *
from users u
where exists
(
select *
from user_attributes ua
where ua.user = u.id
and ua.attribute = 1
)
and exists
(
select *
from user_attributes ua
where ua.user = u.id
and ua.attribute = 2
);
Another way is this: Find all user ids that have both attributes, then select from users table.
select *
from users
where id in
(
select user
from user_attributes
where attribute in (1,2)
group by user
having count(*) = 2
);
In case there are duplicate entries in attributes, you would have to replace count(*) with count(distinct attribute).
There are other ways to approach this. I think these two mentioned are rather straight-forward.
You'll need a group by .... having
SELECT u.name
FROM
users u
JOIN
attributes a
ON u.id = a.user
WHERE a.id IN (1,2)
GROUP BY u.name
HAVING COUNT(*) = 2
Related
I have 3 tables: tags, products and relation table between them.
Relation table looks for example like this:
tagId | ProductId
1 | 1
2 | 1
2 | 9
The user can pick two options "All of these" or "One of these".
So if user picks All of these, it's means that the product must have exactly all of tags which the user chose.
So if user pick tags with id 1 and 2, it should select only product with id 1, because this product has exactly the same tags the user chose. (Another way is if the user picks the tag with id 2, it should select only product with id 9.)
So, the product has to have all tags which the user chose (no more, no less).
SQL that I already have for Any/One of these:
SELECT DISTINCT s.SKU
FROM SKUToEAN as s
LEFT JOIN ProductDetails as p ON s.ProductDetailID=p.id
JOIN ProductTagRelation as ptr ON (ptr.productId=p.id and ptr.tagId IN(Ids of selected tags))
Example behavior:
TagId = 1 it should select => None
TagId = 2 it should select => 9
TagId = 1,2 it should select = 1,9
So probably I need two queries. One for any/one of these ( I already have this one ) and the second for all of these.
With PHP I decide which query to use.
You can GROUP BY on the ProductID and use conditional aggregation based filtering inside the Having clause. MySQL automatically casts boolean values to 0/1 when using in numeric context. So, in order to have a specific tagID value available against a ProductID, its SUM(tagId = ..) should be 1.
All of these:
SELECT ptr.productId, s.SKU
FROM SKUToEAN AS s
LEFT JOIN ProductDetails AS p
ON p.id = s.ProductDetailID
JOIN ProductTagRelation AS ptr
ON ptr.productId = p.id
GROUP BY ptr.productId, s.SKU
HAVING SUM(ptr.tagID = 1) AND -- 1 should be there
SUM(ptr.tagID = 2) AND -- 2 should be there
NOT SUM(ptr.tagID NOT IN (1,2)) -- other than 1,2 should not be there
Is this you are looking for (for all condition)?
select product.id
from products
inner join <table> on products.id = <table>.productId
group by product.id
having group_concat(<table>.tagId order by <table>.tagId separator ',') = '1,2';
Consider the following data set:
users table:
id (int) email (string)
1 first#example.com
2 second#example.com
order_items table:
id (int) user_id (int) generation (string)
1 1 '11'
2 1 '12'
2 1 '12.50'
3 1 '16.00'
4 2 '11'
5 2 '12'
UPDATED question
How can I select users which doesn't have order_items with generation 16.00 and have at least one order_item?
So:
email
second#example.com
1) Returning Users who don't have order item with generation 16 included users with no orders at all.
Assuming you have some kind of id column in order_items table:
select u.* from users u
left outer join order_items oi on (u.id = oi.user_id and oi.generation = 16)
where oi.id is null;
Otherwise use whatever primary key you have in order_items in the where condition to be NULL.
Updated to include answer for the question in comment
2) Returning users who don't have order item with generation 16 but have least one order.
select distinct u.* from users u
left outer join order_items oi16 on (u.id = oi.user_id and oi.generation = 16)
join order_items oiother on (u.id = oiother.user_id and oiother.generation != 16)
where oi16.id is null;
We do the filtering by using a second (normal) join which only returns users where it finds matching rows from the order_items table.
Here we need the distinct because the second join will multiply your rows depending on how many other orders the user have.
Alternatively you can also do a count or sum like this:
select u.*, count(distinct oiother.id) from users u
left outer join order_items oi16 on (u.id = oi.user_id and oi.generation = 16)
join order_items oiother on (u.id = oiother.user_id and oiother.generation != 16)
where oi16.id is null
group by u.id;
This will give you also how many other order items each returned user have. Or omit the count completely and using group by just to return distinct items.
You can use NOT EXISTS() like this:
SELECT * FROM Users u
WHERE NOT EXISTS(SELECT 1 FROM order_items o
WHERE o.userid = u.id
AND o.generation = 16)
That checks if there is a record for this user with order.generation = 16, and if there isn't it selects him.
Or not in()
SELECT * FROM Users u
WHERE u.id NOT IN(SELECT userid FROM order_items o
WHERE o.generation = 16)
That selects the list of users who have order.generation = 16, and select every id except them.
Following query should give you the desired output:
*update*
changed query as per the new result format in the question
As we want the data only from generation table, join with user table is not needed anymore. Here's the updated query:
select id, generation
from mytable where id not in (
select id from mytable
where generation = 16
group by id
);
Here is the SQL fiddle for it.
I have a table for users like this
id | name | password | email
1 saeid ***** asd#asd.com
I have another table called appointments
id | created_by | due_date | notification_send
1 1 ***** 0
I want to get all users from users table where they have at least created one appointment in the appointments table (denoted by created_by field in the appointments table).
I have tried the code below but it fails:
SELECT * FROM users LEFT JOIN appointments a ON persons.id = a.created_by
But obviously it does not work.
One way is to use the exists predicate:
SELECT * FROM users u
WHERE EXISTS (SELECT 1 FROM appointments a WHERE a.created_by = u.id)
Alternatively you could use an inner join, but the exists query corresponds better to your question in my opinion (that is if you only need data from the users table).
The left join says to get all rows from users regardless if they have matching rows in appointments which is not what you want.
You are searching for a match between the table and so I would suggest doing a INNER JOIN rather like below
SELECT * FROM users u
JOIN appointments a ON u.id = a.created_by
Also check your ON clause once I think either this is a typo or a big mistake. You are selecting from users table then why persons.id??
ON persons.id = a.created_by
Try something like this:
http://sqlfiddle.com/#!9/5eba3/2
select * from users c where (select count(*) from appointments where created_by = c.id) > 0;
I have two tables. One contains User and company relationship a show below
User_company
UserId CompanyId
1 2
2 1
3 1
4 2
Another table holds user information
User
Id Name City
1 Peter LA
2 Harry SF
3 John NY
4 Joe CI
How do I make a statement which will give me All the users which are in company 1? Will something like
Select * from User where Id in (Select UserId from User_company where CompanyId = 1)
work?
SELECT * from User
left join User_company on User_company.UserId=User.Id
This would work...
SELECT * works but can be sluggish over time as it may not scale well with more data.
FROM User
WHERE Id in (Select UserId from User_company where CompanyId = 1)
So would this.. - best if you need data from both tables.
SELECT *
FROM User U
INNER JOIN User_Company UC
ON U.ID = UC.UserID
WHERE UC.CompanyID = 1
As would this - Probably the fastest if you just need data from user table.
Select * from User U
where exists (Select * from User_Company UC where U.ID = UC.UserID and CompanyID = 1)
OUTER joins are only needed if you need all records from one table and only those that match in another.
As to which is the best above: it depends on existing indexes and other requirements. Any of the above will return what's been asked for.
Try this
Select u.*
from User u
inner join User_company uc
on u.Id = uc.UserId
and uc.CompanyId = 1
BTW, what's wrong with the query you have posted? It will work as well fine. Just that it's a subquery and you better replace it with Join for performance.
Select * from User where Id in
(Select UserId from User_company where CompanyId = 1)
SELECT U.* FROM User AS U LEFT JOIN
User_company AS UC ON U.Id = UC.UserId WHERE UC.CompanyId = 1
I'm fairly new to mysql and I have no idea if I'm heading in the right direction but I'm having trouble with a mysql query.
I basically have a table of users
id name
---- --------
1 user1
2 user2
3 user3
4 user4
as well as a table of user attributes
id userid attribute
---- ----- ------
1 1 5
2 1 6
3 2 5
4 3 4
I want to be able to select users that have both the attribute 5 and the attribute 6, so in this case I want to return
id name
---- --------
1 user1
I tried using a join like this.
SELECT u.id, u.name FROM users u LEFT JOIN attributes a ON (a.userid = u.id) WHERE a.attribute = 5 AND a.attribute = 6
But obviously that won't work, what is the best way of doing this?
One way to do this would be to use two joins; eg:
SELECT ...
FROM users u
JOIN attributes a5 ON u.id = a5.userid AND a5.attribute = 5
JOIN attributes a6 ON u.id = a6.userid AND a6.attribute = 6
Another way is by grouping (note that I am a MS SQL person, not sure if this is the right syntax for mysql or not):
SELECT u.id, u.name
FROM users u
JOIN attributes a ON u.id = a.userid
WHERE a.attribute IN (5,6)
GROUP BY u.id, u.name
HAVING COUNT(*) = 2
SELECT u.id, u.name FROM users u
INNER JOIN attributes a1 ON u.id = a1.userid
INNER JOIN attributes a2 ON u.id = a2.userid
WHERE a1.attribute = 5 AND a2.attribute = 6
Based on your question, I don't think the other two current answers are satisfactory.
If you want to:
select users that have both the
attribute 5 and the attribute 6
The following query is one way to accomplish that:
select
*
from
users
where
id in (select userid from attributes where attribute = 5)
and
id in (select userid from attributes where attribute = 6)
Hmm, I am not much into SQL, maybe GROUP BY and HAVING will help you:)
Check out the reference: http://www.w3schools.com/sql/sql_having.asp
Changing the query like this would work:
Select all from attributes table that equals 5 or 6 and then check the users who match.
SELECT a.id, u.name
FROM attributes AS a
LEFT JOIN users AS u ON a.id = u.id
WHERE a.attribute = 5 OR a.attribute = 6