I have a table like this.
id
grade_1
grade_2
createdAt
1
1
1
20220304
2
1
1
20220301
3
4
2
20220228
I want to select the current row(in here, id=1) and a row where the grade's value is different with the row I selected.(in here, id=3)
Like This
id
grade_1
grade_2
createdAt
1
1
1
20220304
3
4
2
20220228
I tried to use subquery but it doesn't really worked for me. Is there any way to skip the duplicated value when selecting table?
You can just do it with group by and a max value to retieve the one you want
SELECT
grade_1,
grade_2,
Max(createdAt)
from
yourTable
Group by
grade_1,
grade_2
Related
Say I have the following table:
ID
T
R
1
2
1
3
Y
1
4
1
5
1
6
Y
1
7
I would like to add a column which equals the value from column T based on the last non-null value from column R. This means the following:
ID
T
R
GOAL
1
2
1
3
Y
1
4
Y
3
1
5
4
1
6
Y
4
1
7
6
I do have many ID's so I need to make use of the OVER (PARTITION BY ...) clause. Also, if possible, I would like to use a single statement, like
SELECT *
, GOAL
FROM TABLE
So without any extra select statement.
T is in ascending order so just null it out according to R and take the maximum looking backward.
select *,
max(case when R is not null then T end)
over (
partition by id
order by T
rows between unbounded preceding and 1 preceding
) as GOAL
from TBL
http://sqlfiddle.com/#!18/c927a5/5
There is a table with values as below,
Id Value
1 1
2 1
3 2
4 2
5 3
6 4
7 4
now need to write a query to retrieve value from the table and output should look as
ID Value
1 1
3 2
5 3
6 4
any suggestion ?
The query you want is nothing to do with being distinct, it's a simple aggregation of value with the minimum ID for each:
select Min(id) Id, value
from table
group by value
Using SQL here. Trying to select all rows where the column value is unique within that specific partition.
Have tried:
select *
from dataTable
where value in ( select value
from dataTable
group by tv_id, value
having count(*) > 1)
but it returns the full table-- i think the issue is that the values for many of tv_ids are identical and overlap.
What I have:
tv_id value
1 1
1 2
1 2
1 3
2 1
2 1
2 2
2 3
2 4
3 1
3 1
3 2
What I want:
tv_id value
1 2
1 2
2 1
2 1
3 1
3 1
I have a bunch of tv_ids and essentially, I only want the rows where the value is not unique within each tv_id.
Ex: I don't want tv_id, value: 3, 2 because it is the only combination in the data.
Thanks in advance!
Maybe something like this does the trick
Oracle Option
I include this oracle version because it enables you to understand better what are you querying.
select tv_id, value
from dataTable
where (tv_id, value) in (
select tv_id, value
from dataTable
group by tv_id, value
having count(1) > 1
)
SQL
But this is a standard sql version that will work with almost any database engine
select tv_id, value
from dataTable d1
join (
select tv_id, value
from dataTable
group by tv_id, value
having count(1) > 1
) d2
on d1.tv_id=d2.tv_id
and d1.value=d2.value
You need to query the same table twice because the group by makes a distinct in your data, so you won't retrieve duplicated rows as you show in your expected output.
I have table like this-
id object_id product_id
1 1 1
2 1 1
4 2 2
6 3 2
7 3 2
8 1 2
9 1 1
I want to delete all rows except these-
1 1 1
4 2 2
6 3 2
9 1 2
Basically there are duplicates and I want to remove them but keep one copy intact.
what would be the most efficient way for this?
If this is a one-off then you can simply identify the records you want to keep like so:
SELECT MIN(id) AS id
FROM yourtable
GROUP BY object_id, product_id;
You want to check that this works before you do the next thing and actually throw records out. To actually delete those duplicate records you do:
DELETE FROM yourtable WHERE id NOT IN (
SELECT MIN(id) AS id
FROM yourtable
GROUP BY object_id, product_id
);
The MIN(id) obviously always returns the record with the lowest id for a set of (object_id, product_id). Change as desired.
There are groups like this;
USER_ID SEQ_ID NAME
1 2 Armut
1 3 Elma
1 4 Kiraz
2 1 Nar
2 2 Uzum
4 3 Sheftali
4 4 Karpuz
4 5 Kavun
After select query I want to see only;
USER_ID SEQ_ID NAME
1 2 Armut
2 1 Nar
4 3 Karpuz
That is, I want the row with the least SEQ_ID for each USER_ID. What SQL query will give me this result?
Best regards
SELECT USER_ID, SEQ_ID, NAME
FROM table
WHERE NAME IN ('Armut', 'Nar', 'Karpuz')
ORDER BY USER_ID
If you have something else in mind, please clarify your question.
Looks to me like it should be:
SELECT USER_ID, MIN(SEQ_ID) AS SEQ_ID, NAME
FROM table
GROUP BY USER_ID, NAME
ORDER BY USER_ID;