I have this
id value
-----!-----
1 3
2 3
1 2
1 1
i have tried using
SELECT id,sum(value) FROM table GROUP BY id
but it shows something different.
id ! value
--------------
1 6
2 3
And i want to add values based on their id's but keeping id's there
id ! value
--------------
1 6
2 3
1 6
1 6
Please help
Thank you
Are you looking for this?
SELECT t.id, q.value
FROM Table1 t JOIN
(
SELECT id, SUM(value) value
FROM Table1
GROUP BY id
) q ON t.id = q.id
Output:
| ID | VALUE |
|----|-------|
| 1 | 6 |
| 2 | 3 |
| 1 | 6 |
| 1 | 6 |
Here is SQLFiddle demo
The naive approach would be :
select id, (select sum(value) from tbl where id = t1.id) value
from tbl t1
Related
Today I have posted a question and got a good answer: Stuck in building mysql query.
I though it helped me, but I've discovered that it returns wrong data. So I'm reposting the question here, with an answer I received, as well I will explain the problem why it is not working for me.
Example of data:
id | item_id | user_id | bid_price
----------------------------------
1 | 1 | 11 | 1
2 | 1 | 12 | 2
3 | 1 | 13 | 3
4 | 1 | 14 | 1
5 | 1 | 15 | 4
6 | 2 | 16 | 2
7 | 2 | 17 | 1
8 | 3 | 18 | 2
9 | 3 | 19 | 3
10 | 3 | 18 | 2
Expected result:
id | item_id | user_id | bid_price
----------------------------------
1 | 1 | 11 | 1
7 | 2 | 17 | 1
8 | 3 | 18 | 2
Offered solution:
select m.id, m.item_id, m.user_id, m.bid_price
from my_table m
inner join (
select item_id, min(id) min_id, min(bid_price) min_price
from my_table
where item_id IN (1,2,3)
group by item_id
) t on t.item_id = m.item_id
and t.min_price= m.bid_price
and t.min_id = m.id
The problem:
In the sub query the minimum ID is selected entire the group by (item_id) statement and doesn't reflects according to minimum bid_price.
In other words, the minimum id is selected not depending on the price field at all. So, in the result I will get minimum price and minimum id of the group, but this will not be the same row! The id can be related to the row with another bet_price value.
How this query can be adjusted? Thank you in advance!
SELECT min(m.id) AS id, m.item_id, m.user_id, m.bid_price
FROM my_table m
INNER JOIN (
SELECT item_id, min(bid_price) AS min_price
FROM my_table
GROUP BY item_id
) t ON t.item_id = m.item_id
AND t.min_price= m.bid_price
GROUP BY item_id
Output
id item_id user_id bid_price
1 1 11 1
7 2 17 1
8 3 18 2
Live Demo
http://sqlfiddle.com/#!9/a52dc6/13
SELECT DISTINCT
t1.item_id,
t1.bid_price
FROM tab1 t1
WHERE NOT exists(SELECT 1
FROM tab1 t2
WHERE t2.item_id = t1.item_id
AND t2.bid_price < t1.bid_price)
AND t1.item_id IN (1, 2, 3);
http://sqlfiddle.com/#!9/615e0a/5
Consider this table:
I need to make a SQL query which returns highlighted rows. In other words: rows which are linked to each other by idContactTo.
Example:
1 has contact to 2, 2 has contact to 1 - they are linked and should be in result table. But even 1 has contact to 3 it doesn't mean that 3 has contact to 1 - they aren't linked.
You can do it via INNER JOIN,
SELECT a.*
FROM tableName a
INNER JOIN tableName b
ON a.idContantOwner = b.idContactTo AND
b.idContantOwner = a.idContactTo
SQLFiddle Demo
Another way to do it
SELECT t.*
FROM
(
SELECT MiN(id) min_id, MAX(id) max_id
FROM Table1
GROUP BY LEAST(idContactOwner, idContactTo),
GREATEST(idContactOwner, idContactTo)
HAVING COUNT(*) = 2
) q JOIN Table1 t
ON t.id IN(q.min_id, q.max_id)
Output:
| ID | IDCONTACTOWNER | IDCONTACTTO |
|----|----------------|-------------|
| 1 | 1 | 2 |
| 2 | 2 | 1 |
| 4 | 3 | 4 |
| 5 | 4 | 3 |
Here is SQLFiddle demo
There is a requirement that I need to fill a group-id in a table as combination of item-id and auto-id. The table is as follows;
----------------------------------------
Item_id | Auto_id | Group_id
----------------------------------------
1 | 1 | 1
1 | 2 | 1
2 | 3 | 3
2 | 4 | 3
3 | 5 | 5
3 | 6 | 5
3 | 7 | 5
4 | 8 | 8
4 | 9 | 8
5 | 10 | 10
6 | 11 | 11
The two columns would be populated already that is Item_id and Auto_id, and we need to fill group_id. The relation would be like for each repetitive item_id the group_id would be minimum of auto_id.
I hope I make it clear. If possible please help.
Thanks,
Ashish
You can use a subquery, with a group by, where you calculate the minimum auto_id for each item_id. Then you can join this subquery with the original table:
SELECT t1.Item_id, t1.Auto_id, t2.Group_id
FROM
yourtable t1 INNER JOIN (
SELECT Item_Id, MIN(Auto_id) Group_id
FROM yourtable
GROUP BY Item_Id) t2
ON t1.Item_Id=t2.ItemId
Please see fiddle here.
If you need to update an existing column, you could use this UPDATE query:
UPDATE
yourtable t1 INNER JOIN (
SELECT Item_Id, MIN(Auto_id) Group_id
FROM yourtable
GROUP BY Item_id) t2
ON t1.Item_Id=t2.Item_Id
SET
t1.Group_id=t2.Group_id
Fiddle is here.
I have a users table with columns: user_id, teacher_id1, teacher_id2, teacher_id3
and
teachers table with id
Each user can have the same id's for teacher_id1, teacher_id2, teacher_id3
I would like to count how many users have same teacher.
User table
+----------------------------------------+
| user_Id teacher_id1 teacher_id2 teacher_id3 |
+----------------------------------------+
| 1 1 1 1 |
| 2 2 1 3 |
| 3 2 3 3 |
| 4 2 2 2 |
+----------------------------------------+
Teacher table
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
Count for $id1 is: 2
Count for $id2 is: 3
Count for $id3 is: 2
I tried something like this, but it is not correct!
SELECT COUNT(*) FROM users WHERE concat_ws('',teacher_id1 OR teacher_id2
OR teacher_id3) like '{$id}' ";
You have data in three different columns. You need to combine it into one column, to get the distinct counts that you want. For this, you can use union all. Then the count is simply count(distinct):
select teacher_id, COUNT(distinct USER_ID)
from ((select user_id, teacher_id1 as teacher_id
from t
) union all
(select user_id, teacher_id2
from t
) union all
(select user_id, teacher_id3
from t
)
) s
group by teacher_id;
Try this query
select b.id, count(*)
from
tbl1 a
inner join
tbl2 b
on b.id = teacher_id1 or b.id = teacher_id2 or b.id = teacher_id3
group by b.id
SQL FIDDLE:
| ID | COUNT(*) |
-----------------
| 1 | 2 |
| 2 | 3 |
| 3 | 2 |
I have a mysql problem. I have two tables like this that I need to join together.
table:
id otherid2
1 | 1
2 | 1
3 | 2
4 | 2
table2:
otherid otherid2
1 | 1
2 | 1
3 | 2
4 | 2
I'm using:
SELECT id,otherid FROM table INNER JOIN table2 ON table.otherid2=table2.otherid2
This gives me:
id otherid
1 | 1
1 | 2
2 | 1
2 | 2
3 | 3
3 | 4
4 | 3
4 | 4
As you can see I get duplicates of id as there is otherid2s that is not unique in table2. What I need is to INNER JOIN DISTINCT in some way, I only want the result to be as below. Not duplicates.
This is what I want:
id otherid
1 | 1
2 | 1
3 | 3
4 | 3
Can I do this in an easy way?
If you want the row with the lowest id in table2, this should probably do it
SELECT id, min(otherid)
FROM table
INNER JOIN table2
ON table.otherid2=table2.otherid2
GROUP BY id
In your comment you wanted the lowest, then I'd suggest a group by and a min aggregator
SELECT id, MIN(otherid) AS otherid ... GROUP BY id