I have a table like this
Column1 | Column2
-------------------
A | 1
A | 2
A | 3
B | 4
B | 5
B | 3
C | 2
C | 2
C | 2
D | 7
D | 8
D | 9
I want to output it as
A | B | C | D
--------------------
1 | 4 | 2 | 7
2 | 5 | 2 | 8
3 | 3 | 2 | 9
It will have fixed Rows/Columns like A,B,C,D.
Could you suggest a query in SQL Server 2005/2008?
it's better to know your clustered key in the table, since the order might be different after the result. Martin is right, try this out, it will get you started:
SELECT pvt.A,
pvt.B,
pvt.C,
pvt.D
FROM (SELECT *,
row=ROW_NUMBER() OVER(PARTITION BY Column1 ORDER BY (SELECT 1))
FROM yourtable) AS A
PIVOT (MIN(Column2) FOR Column1 IN ([A], [B], [C], [D]))
AS pvt
Related
I have a table referrals:
id | user_id_owner | firstname | is_active | user_type | referred_at
----+---------------+-----------+-----------+-----------+-------------
3 | 2 | c | t | agent | 3
5 | 3 | e | f | customer | 5
4 | 1 | d | t | agent | 4
2 | 1 | b | f | agent | 2
1 | 1 | a | t | agent | 1
And another table activations
id | user_id_owner | referral_id | amount_earned | activated_at | app_id
----+---------------+-------------+---------------+--------------+--------
2 | 2 | 3 | 3.0 | 3 | a
4 | 1 | 1 | 6.0 | 5 | b
5 | 4 | 4 | 3.0 | 6 | c
1 | 1 | 2 | 2.0 | 2 | b
3 | 1 | 2 | 5.0 | 4 | b
6 | 1 | 2 | 7.0 | 8 | a
I am trying to generate another table from the two tables that has only unique values for referrals.id and returns as one of the columns the count for each apps as best_selling_app_count.
Here is the query I ran:
with agents
as
(select
referrals.id,
referral_id,
amount_earned,
referred_at,
activated_at,
activations.app_id
from referrals
left outer join activations
on (referrals.id = activations.referral_id)
where referrals.user_id_owner = 1),
distinct_referrals_by_id
as
(select
id,
count(referral_id) as activations_count,
sum(coalesce(amount_earned, 0)) as amount_earned,
referred_at,
max(activated_at) as last_activated_at
from
agents
group by id, referred_at),
distinct_referrals_by_app_id
as
(select id, app_id as best_selling_app,
count(app_id) as best_selling_app_count
from agents
group by id, app_id )
select *, dense_rank() over (order by best_selling_app_count desc) best_selling_app_rank
from distinct_referrals_by_id
inner join distinct_referrals_by_app_id
on (distinct_referrals_by_id.id = distinct_referrals_by_app_id.id);
Here is the result I got:
id | activations_count | amount_earned | referred_at | last_activated_at | id | best_selling_app | best_selling_app_count | best_selling_app_rank
----+-------------------+---------------+-------------+-------------------+----+------------------+------------------------+-----------------------
2 | 3 | 14.0 | 2 | 8 | 2 | b | 2 | 1
1 | 1 | 6.0 | 1 | 5 | 1 | b | 1 | 2
2 | 3 | 14.0 | 2 | 8 | 2 | a | 1 | 2
4 | 1 | 3.0 | 4 | 6 | 4 | c | 1 | 2
The problem with this result is that the table has a duplicate id of 2. I only need unique values for the id column.
I tried a workaround by harnessing distinct that gave desired result but I fear the query results may not be reliable and consistent.
Here is the workaround query:
with agents
as
(select
referrals.id,
referral_id,
amount_earned,
referred_at,
activated_at,
activations.app_id
from referrals
left outer join activations
on (referrals.id = activations.referral_id)
where referrals.user_id_owner = 1),
distinct_referrals_by_id
as
(select
id,
count(referral_id) as activations_count,
sum(coalesce(amount_earned, 0)) as amount_earned,
referred_at,
max(activated_at) as last_activated_at
from
agents
group by id, referred_at),
distinct_referrals_by_app_id
as
(select
distinct on(id), app_id as best_selling_app,
count(app_id) as best_selling_app_count
from agents
group by id, app_id
order by id, best_selling_app_count desc)
select *, dense_rank() over (order by best_selling_app_count desc) best_selling_app_rank
from distinct_referrals_by_id
inner join distinct_referrals_by_app_id
on (distinct_referrals_by_id.id = distinct_referrals_by_app_id.id);
I need a recommendation on how best to achieve this.
I am trying to generate another table from the two tables that has only unique values for referrals.id and returns as one of the columns the count for each apps as best_selling_app_count.
Your question is really complicated with a very complicated SQL query. However, the above is what looks like the actual question. If so, you can use:
select r.*,
a.app_id as most_common_app_id,
a.cnt as most_common_app_id_count
from referrals r left join
(select distinct on (a.referral_id) a.referral_id, a.app_id, count(*) as cnt
from activations a
group by a.referral_id, a.app_id
order by a.referral_id, count(*) desc
) a
on a.referral_id = r.id;
You have not explained the other columns that are in your result set.
I have to perform a query where I can count the number of distinct codes per Id.
|Id | Code
------------
| 1 | C
| 1 | I
| 2 | I
| 2 | C
| 2 | D
| 2 | D
| 3 | C
| 3 | I
| 3 | D
| 4 | I
| 4 | C
| 4 | C
The output should be something like:
|Id | Count | #Code C | #Code I | #Code D
-------------------------------------------
| 1 | 2 | 1 | 1 | 0
| 2 | 3 | 1 | 0 | 2
| 3 | 3 | 1 | 1 | 1
| 4 | 2 | 2 | 1 | 0
Can you give me some advise on this?
This answers the original version of the question.
You are looking for count(distinct):
select id, count(distinct code)
from t
group by id;
If the codes are only to the provided ones, the following query can provide the desired result.
select
pvt.Id,
codes.total As [Count],
COALESCE(C, 0) AS [#Code C],
COALESCE(I, 0) AS [#Code I],
COALESCE(D, 0) AS [#Code D]
from
( select Id, Code, Count(code) cnt
from t
Group by Id, Code) s
PIVOT(MAX(cnt) FOR Code IN ([C], [I], [D])) pvt
join (select Id, count(distinct Code) total from t group by Id) codes on pvt.Id = codes.Id ;
Note: as I can see from sample input data, code 'I' is found in all of Ids. Its count is zero for Id = 3 in the expected output (in the question).
Here is the correct output:
DB Fiddle
I have a table of IDs, with some duplicates and I need to create a sequence based on the IDs. I'm trying to achieve the following.
[ROW] [ID] [SEQID]
1 11 1
2 11 2
3 12 1
4 13 1
5 13 2
I'm using an old version of the H2 DB which doesn't have use of windows functions so I have todo this using straight SQL. I have tried joining the table on itself but I'm not getting the result I want as the duplicate values cause issues, any ideas? I have unique identifier in row number, but not sure how to use this to achieve what I want?
SELECT A.ID, COUNT(*) FROM TABLE A
JOIN TABLE B
ON A.ID = B.ID
WHERE A.ID >= B.ID
GROUP BY A.ID;
Use a subquery that counts the seqid:
select
t.row, t.id,
(select count(*) from tablename where id = t.id and row <= t.row) seqid
from tablename t
It's not as efficient as window functions but it does what you expect.
See the demo (for MySql but it's standard SQL).
Results:
| row | id | seqid |
| --- | --- | ----- |
| 1 | 11 | 1 |
| 2 | 11 | 2 |
| 3 | 12 | 1 |
| 4 | 13 | 1 |
| 5 | 13 | 2 |
I'm using PostgreSQL 9.4, and I have a table with 13 million rows and with data roughly as follows:
a | b | u | t
-----+---+----+----
foo | 1 | 1 | 10
foo | 1 | 2 | 11
foo | 1 | 2 | 11
foo | 2 | 4 | 1
foo | 3 | 5 | 2
bar | 1 | 6 | 2
bar | 2 | 7 | 2
bar | 2 | 8 | 3
bar | 3 | 9 | 4
bar | 4 | 10 | 5
bar | 5 | 11 | 6
baz | 1 | 12 | 1
baz | 1 | 13 | 2
baz | 1 | 13 | 2
baz | 1 | 13 | 3
There are indices on md5(a), on b, and on (md5(a), b). (In reality, a may contain values longer than 4k chars.) There is also a primary key column of type SERIAL which I have omitted above.
I'm trying to build a query which will return the following results:
a | b | u | t | z
-----+---+----+----+---
foo | 1 | 1 | 10 | 3
foo | 1 | 2 | 11 | 3
foo | 2 | 4 | 1 | 3
foo | 3 | 5 | 2 | 3
bar | 1 | 6 | 2 | 5
bar | 2 | 7 | 2 | 5
bar | 2 | 8 | 3 | 5
bar | 3 | 9 | 4 | 5
bar | 4 | 10 | 5 | 5
bar | 5 | 11 | 6 | 5
In these results, all rows are deduplicated as if GROUP BY a, b, u, t were applied, z is a count of distinct values of b for every partition over a, and only rows with a z value greater than 2 are included.
I can get just the z filter working as follows:
SELECT a, COUNT(b) AS z from (SELECT DISTINCT a, b FROM t) AS foo GROUP BY a
HAVING COUNT(b) > 2;
However, I'm stumped on combining this with the rest of the data in the table.
What's the most efficient way to do this?
Your first step can be simpler already:
SELECT md5(a) AS md5_a, count(DISTINCT b) AS z
FROM t
GROUP BY 1
HAVING count(DISTINCT b) > 2;
Working with md5(a) in place of a, since a can obviously be very long, and you already have an index on md5(a) etc.
Since your table is big, you need an efficient query. This should be among the fastest possible solutions - with adequate index support. Your index on (md5(a), b) is instrumental but - assuming b, u, and t are small columns - an index on (md5(a), b, u, t) would be even better for the second step of the query (the lateral join).
Your desired end result:
SELECT DISTINCT ON (md5(t.a), b, u, t)
t.a, t.b, t.u, t.t, a.z
FROM (
SELECT md5(a) AS md5_a, count(DISTINCT b) AS z
FROM t
GROUP BY 1
HAVING count(DISTINCT b) > 2
) a
JOIN t ON md5(t.a) = md5_a
ORDER BY 1, 2, 3, 4; -- optional
Or probably faster, yet:
SELECT a, b, u, t, z
FROM (
SELECT DISTINCT ON (1, 2, 3, 4)
md5(t.a) AS md5_a, t.b, t.u, t.t, t.a
FROM t
) t
JOIN (
SELECT md5(a) AS md5_a, count(DISTINCT b) AS z
FROM t
GROUP BY 1
HAVING count(DISTINCT b) > 2
) z USING (md5_a)
ORDER BY 1, 2, 3, 4; -- optional
Detailed explanation for DISTINCT ON:
Select first row in each GROUP BY group?
Suppose I have these two tables :
TABLEA TABLEB
----------- -----------
ID | NAME ID | TABLEA_ID | NAME
1 | ... 1 | 1 | ...
2 | 2 | 2 | ...
3 | 3 | 2 |
4 | 4 | 2 |
5 | 3 |
6 | 3 |
7 | 4 |
8 | 2 |
I want an SQL SELECT statement that can generate such result when TABLEA.ID = TABLEB.TABLEA_ID, you can note here I don't care about grouping or ordering, I just want to generate a incremented value for each line of the same TABLEB.TABLEA_ID.
ID | TABLEA_ID | ORDER_INDEX | NAME
1 | 1 | 0 | ...
2 | 2 | 0 | ...
3 | 2 | 1 |
4 | 2 | 2 |
5 | 3 | 0 |
6 | 3 | 1 |
7 | 4 | 0 |
8 | 2 | 3 |
I tried without success to use rownum in several combination of sub-selects to generate the ORDER_INDEX depending on the value in TABLEA_ID.
Do you have hint to do that in plain SQL, is it even possible with plain SQL.
Is it possible via a PL/SQL ? And how if possible ?
Thank you very much in advance.
I believe that this is what you want:
SELECT B.ID, B.TABLEA_ID,
ROW_NUMBER() OVER(PARTITION BY B.TABLEA_ID ORDER BY B.ID) - 1 ORDER_INDEX,
B.NAME -- OR A.NAME, its not clear on your question
FROM TABLEB B
LEFT JOIN TABLEA A
ON B.TABLEA_ID = A.ID
Something like this:
SELECT
TableB.ID,
TableB.TableA_ID,
ROW_NUMBER() OVER(PARTITION BY TableB.TableA_ID ORDER BY TableB.TableA_ID) AS ORDER_INDEX,
TableB.Name
FROM
TableA
JOIN TableB
ON TableA.ID=TableB.TableA_ID
ORDER BY TableB.ID
How about
ROW_NUMBER() OVER (PARTITION BY TABLEA_ID ORDER BY ID ASC) AS ORDER_INDEX
as the definition of ORDER_INDEX