|id|last|
|2 |NULL|
|2 |2018|
|3 |NULL|
|3 |NULL|
|4 |2011|
|4 |2013|
This is what my current table looks like. A new 'status' column is to be created for each 'id' that must have the below 3 values.
1 - If Similar id and only one NULL value
2 - If Similar id and no NULL value
0 - If Similar id and both NULL value
EXAMPLE: Id 2 will get 1, id 3 will be assigned 0 and id 4 will get 2. There can be only 2 similar ids in the id table (there are no 3 values of 2 or 4)
I could find the similar id, but having difficulties writing the cases
select id
from table
group by id
having count(id) = 2
We can determine the status values by using aggregation:
WITH cte AS (
SELECT id,
CASE WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = 1
THEN 1
WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = 0
THEN 2
WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = COUNT(*)
THEN 0 ELSE -1 END AS status
FROM yourTable
GROUP BY id
)
SELECT t1.*, t2.status
FROM yourTable t1
INNER JOIN cte t2
ON t1.id = t2.id;
Note that I assign a status value of -1 to any id which does not meet one of the three criteria. This would include any id which only appears once, among other edge cases.
You can do it this way
select a.id, last,
case
when exists(select 1 from _table b where a.id = b.id and coalesce(b.last,0) <> coalesce(a.last,0) and (a.last is null or b.last is null))
then 1
when exists(select 1 from _table b where a.id = b.id
and coalesce(b.last,0) <> coalesce(a.last,0))
and not exists(select 1 from _table b where a.id = b.id
and b.last is null)
then 2
when exists(select 1 from _table b where a.id = b.id )
and exists(select 1 from _table b where a.id = b.id and b.last is null and a.last is null having count(*) =
(select count(*) from _table b where a.id = b.id))
then 0
end as status
from _table a
Output:
id last status
2 NULL 1
2 2018 1
3 NULL 0
3 NULL 0
4 2011 2
4 2013 2
If you want one row per id:
select id,
(case count(*) filter (value is null)
when 1 then 1
when 0 then 2
when 2 then 3
end) as status
from t
group by id;
If you want this as a column on the original data, use window functions:
select t.*,
(case count(*) filter (value is null) over (partition by id)
when 1 then 1
when 0 then 2
when 2 then 3
end) as status
from t;
Related
Imagine this data.
Id
Type
1
A
1
B
1
B
2
A
3
B
I want to select table and ad two columns turning it to this. How can i do it? (In teradata)
Id
Type
Id with both A+B
Id with only A
1
A
1
0
1
B
1
0
1
B
1
0
2
A
0
1
3
B
0
0
I'm not familiar with teradata but in standard SQL next query should be working:
SELECT
T.*,
CASE WHEN Cnt = 2 THEN 1 ELSE 0 END AS BOTH_TYPES_PRESENT,
CASE WHEN Cnt = 1 AND Type = 'A' THEN 1 ELSE 0 END AS ONLY_A_PRESENT
FROM T
LEFT JOIN (
SELECT Id, COUNT(DISTINCT Type) Cnt FROM T WHERE Type IN ('A', 'B') GROUP BY Id
) CNT ON T.Id = CNT.Id;
SQL online editor
Edit: when 5 or 9 does not exist, i need a null value (or another flag)
I have 3 columns. SECTION, STATUS and NAME. Within a SECTION there are a maximum of 10 rows (STATUS 1 to 10). I have to compare the value of NAME for STATUS 5 and 9 within a SECTION. AND then indicate if those 2 NAMES (for STATUS 5 and 9) are the same for each SECTION.
section status name
1 5 a
1 6 a
1 9 b
2 4 c
2 5 d
2 9 d
2 10 d
3 5 e
3 10 e
Desired output
Section equalnames
1 no
2 yes
3 null/flag
select
a.section,
case
when a.name = b.name then 'YES'
when a.name <> b.name then 'NO'
when (a.name is null or b.name is null) then 'NULL' end
from
(select * from <table> where status = 5) a
full join (select * from <table> where status = 9) b
on a.section = b.section
With conditional aggregation:
SELECT section,
MAX(CASE WHEN status = 5 THEN name END) =
MAX(CASE WHEN status = 9 THEN name END) equalnames
FROM tablename
WHERE status IN (5, 9)
GROUP BY section
ORDER BY section
See the demo.
Results:
section | equalnames
------- | ----------
1 | f
2 | t
3 | null
You could try using a left join on same table for 5 and 9
select a.section, a.status s5, a.name n5, b.status b9, b.name n9
, case when a.name = b.name the yes
when a.name is null or b.name is nul the NULL
when a.name <> b.name then no end equalname
from my_table a
left join my_table b a.section = b.section and a.status =5 and b.status=9
A more optimised solution could be with cte and window function:
with cte as (
select section, count(status)over(partition by section,name order by section) count_with_same_name,
count(status)over(partition by section order by section) count_with_different_name
from tname where status in (5,9))
select section,(case when (max(count_with_same_name)=2) then 'Yes' when (max(count_with_different_name)=2) then 'No' else 'null/flag' end)
from cte
group by section
Output:
I think you just want conditional aggregation:
select section,
(case when min(case when status = 5 then name end) =
min(case when status = 9 then name end)
then 'yes'
when count(case when status in (5, 9) then status end) < 2
then 'null/flag'
else 'no'
end)
from t
group by section;
No join is needed and I would not advise one for this problem.
I have a scenario where I need to fetch all the records within an ID for the same source. Given below is my input set of records
ID SOURCE CURR_FLAG TYPE
1 IBM Y P
1 IBM Y OF
1 IBM Y P
2 IBM Y P
2 TCS Y P
3 IBM NULL P
3 IBM NULL P
3 IBM NULL P
4 IBM NULL OF
4 IBM NULL OF
4 IBM Y ON
From the above settings, I need to select all the records with source as IBM within that same ID group.Within the ID group if there is at least one record with a source other than IBM, then I don't want any record from that ID group. Also, we need to fetch only those records where at least one record in that ID group with curr_fl='Y'
In the above scenario even though the ID=3 have a source as IBM, but there is no record with CURR_FL='Y', my query should not fetch the value.In the case of ID=4, it can fetch all the records with ID=4, as one of the records have value='Y'.
Also within the group which has satisfied the above condition, I need one more condition for source_type. if there are records with source_type='P', then I need to fetch only that record.If there are no records with P, then I will search for source_type='OF' else source_type='ON'
I have written a query as given below.But it's running for long and not fetching any results. Is there any better way to modify this query
select
ID,
SOURCE,
CURR_FL,
TYPE
from TABLE a
where
not exists(select 1 from TABLE B where a.ID = B.ID and source <> 'IBM')
and exists(select 1 from TABLE C where a.ID = C.ID and CURR_FL = 'Y') and
(TYPE, ID) IN (
select case type when 1 then 'P' when 2 then 'OF' else 'ON' END TYPE,ID from
(select ID,
max(priority) keep (dense_rank first order by priority asc) as type
from ( select ID,TYPE,
case TYPE
when 'P' then 1
when 'OF' then 2
when 'ON' then 3
end as priority
from TABLE where ID
in(select ID from TABLE where CURR_FL='Y') AND SOURCE='IBM')
group by ID))
I think you can just do a single aggregation over your table by ID and check for the yes flag as well as assert that no non IBM source appears. I do this in a CTE below, and then join back to your original table to return full matching records.
WITH cte AS (
SELECT
ID,
CASE WHEN SUM(CASE WHEN TYPE = 'P' THEN 1 ELSE 0 END) > 0
THEN 1
WHEN SUM(CASE WHEN TYPE = 'OF' THEN 1 ELSE 0 END) > 0
THEN 2
WHEN SUM(CASE WHEN TYPE = 'ON' THEN 1 ELSE 0 END) > 0
THEN 3 ELSE 4 END AS p_type
FROM yourTable
GROUP BY ID
HAVING
SUM(CASE WHEN CURR_FLAG = 'Y' THEN 1 ELSE 0 END) > 0 AND
SUM(CASE WHEN SOURCE <> 'IBM' THEN 1 ELSE 0 END) = 0
)
SELECT t1.*
FROM yourTable t1
INNER JOIN cte t2
ON t1.ID = t2.ID
WHERE
t2.p_type = 1 AND t1.TYPE = 'P' OR
t2.p_type = 2 AND t1.TYPE = 'OF' OR
t2.p_type = 3 AND t1.TYPE = 'ON';
I have the following table, and I want to set the value of deleted column to zero for only one of the records that have duplicate names.
id name deleted
------------------------
1 a 1
2 a 1
3 a 1
4 b 1
5 c 1
6 d 1
so the output will be:
id name deleted
------------------------
1 a 0
2 a 1
3 a 1
4 b 0
5 c 0
6 d 0
If your dbms is SQL-Server( >= 2005) you can use a CTE with ROW_NUMBER:
WITH CTE AS
(
SELECT ID, Name, Deleted,
RN = ROW_NUMBER() OVER(PARTITION BY name ORDER BY ID)
FROM dbo.T
)
UPDATE CTE
SET Deleted = 0
WHERE RN = 1
DEMO
UPDATE Tbl SET deleted = 0 WHERE id IN
(SELECT MIN(id) FROM Tbl GROUP BY name)
UPDATE A
SET A.deleted = 0
FROM Tbl A
LEFT JOIN Tbl B
ON A.Name = B.Name
AND A.Id > B.Id
WHERE B.Id IS NULL
I have two tables. Table A has an id column. Table B has an Aid column and a type column. Example data:
A: id
--
1
2
B: Aid | type
----+-----
1 | 1
1 | 1
1 | 3
1 | 1
1 | 4
1 | 5
1 | 4
2 | 2
2 | 4
2 | 3
I want to get all the IDs from table A where there is a certain amount of type 1 and type 3 actions. My query looks like this:
SELECT id
FROM A
WHERE (SELECT COUNT(type)
FROM B
WHERE B.Aid = A.id
AND B.type = 1) = 3
AND (SELECT COUNT(type)
FROM B
WHERE B.Aid = A.id
AND B.type = 3) = 1
so on the data above, just the id 1 should be returned.
Can I combine the 2 subqueries somehow? The goal is to make the query run faster.
Does postgres support CTEs?
WITH counts (Counts, Type, Aid) as (
select count(type), type
from b group by Type, Aid
)
select id
from A
join Counts B1 on b1.Aid = a.id and b1.type = 1
join Counts B3 on b3.Aid = a.id and b3.type = 3
where
b1.counts = 3 and b3.counts = 1
I'd suggest comparing the execution plans, but I suspect it would be similar since everything should get collapsed before execution.
Select ...
From A
Join (
Select B.Id
, Sum ( Case When B.Type = 1 Then 1 Else 0 End ) As Type1Count
, Sum ( Case When B.Type = 3 Then 1 Else 0 End ) As Type3Count
From B
Where B.Type In(1,3)
Group By B.Id
) As Z
On Z.Id = A.Id
Where Z.Type1Count = 3
And Z.Type3Count = 1
This works in TSQL, does it work in Postgres?
SELECT A.ID
FROM A
WHERE A.ID in
(
SELECT AID
FROM B
GROUP BY AID
HAVING
SUM(CASE WHEN Type = 1 THEN 1 ELSE 0 END) = 3
OR SUM(CASE WHEN Type = 3 THEN 1 ELSE 0 END) = 1
)
Another alternative:
SELECT DISTINCT Aid FROM (
SELECT Aid,type,count(*) as n from B
GROUP BY Aid,type, ) as g
WHERE ( g.n=1 AND g.type = 3 )
OR ( g.n=3 AND g.type = 1 )
I doubt this will perform better than your original, though.
You seem to be doing the best strategy: counting only the candidate rows.
Perhaps some redundant prefiltering might help:
SELECT DISTINCT Aid FROM (
SELECT Aid,type,count(*) as n from B
WHERE g.type = 3 OR g.type = 1 -- prefilter
GROUP BY Aid,type, ) as g
WHERE ( g.n=1 AND g.type = 3 )
OR ( g.n=3 AND g.type = 1 )