I need to know how to narrow down my partitioning window with a condition. For instance, if I have the following:
SELECT
T1.*,
COUNT(T1.ID) OVER (PARTITION BY ID)
FROM TBL T1
WHERE /* some other conditions */;
I need the ID partition to only be a subset of all the identical ID's that have T1.TYPE = 'J'.
+---------+--------+---------------+--------+
| ID | TYPE | OTH1 | OTH2 |
+---------+--------+---------------+--------+
| 1 | K | 500 | RER |
| 1 | J | 503 | LEL |
| 1 | J | 534 | KEL |
| 2 | J | 536 | NULL |
| 2 | J | 667 | ERT |
| 2 | J | 98 | NULL |
+---------+--------+---------------+--------+
In this data set, I need to only consider my window count if TYPE = J, so for ID = 1, the count should be 2 rather than 3 since the first row is TYPE = K (ID = 2 where the count is 3).
Is this possible?
Perhaps conditional aggregation is what you want here:
SELECT
t.*,
COUNT(CASE WHEN TYPE = 'J' THEN 1 END) OVER (PARTITION BY ID) cnt
FROM TBL t
If you only wanted to display this count for those records actually having the J type, then we could try:
SELECT
t.*,
CASE WHEN TYPE = 'J'
THEN COUNT(CASE WHEN TYPE = 'J' THEN 1 END) OVER (PARTITION BY ID)
ELSE 0 END cnt
FROM TBL t
Related
I have the following data in a table, this is a single column shown from a table that has multiple columns, but only data from this column needs to be pulled into two column output using a query:
+----------------+--+
| DataText | |
| 1 DEC20 DDD | |
| 1 JUL20 DDD | |
| 1 JAN21 DDD | |
| 1 JUN20 DDD500 | |
| 1 JUN20 DDD500 | |
| 1 JUN20DDDD500 | |
| 1 JUN20DDDD500 | |
| 1 JUL20 DDD800 | |
| 1 JUL20 DDD800 | |
| 1 JUL20DDDD800 | |
| 1 JUL20DDDD400 | |
| 1 JUL20DDDD400 | |
+----------------+--+
Required result: distinct values based on the first 13 characters of the data, split into two columns based on "long data", and "short data", BUT only giving the first 13 characters in output for both columns:
+-------------+-------------+
| ShortData | LongData |
| 1 DEC20 DDD | 1 JUN20 DDD |
| 1 JUL20 DDD | 1 JUN20DDDD |
| 1 JAN21 DDD | 1 JUL20 DDD |
| | 1 JUL20DDDD |
+-------------+-------------+
Something like:
Select
(Select DISTINCT LEFT(DataText,13)
From myTable)
Where LEN(DataText)=13) As ShortData
,
(Select DISTINCT LEFT(DataText,13)
From myTable)
Where LEN(DataText)>13) As LongData
I would also like to query/"scan" the table only once if possible. I can't get any of the SO examples modified to make such a query work.
This is quite ugly, but doable. As a starter, you need a column that defines the order of the rows - I assumed that you have such a column, and that is called id.
Then you can select the distinct texts, put them in separate groups depending on their length, and finally pivot:
select
max(case when grp = 0 then dataText end) shortData,
max(case when grp = 1 then dataText end) longData
from (
select
dataText,
grp,
row_number() over(partition by grp order by id) rn
from (
select
id,
case when len(dataText) <= 13 then 0 else 1 end grp,
substring(dataText, 1, 13) dataText
from (select min(id) id, dataText from mytable group by dataText) t
) t
) t
group by rn
If you are content with ordering the records by the string column itself, it is a bit simpler (and, for your sample data, it produces the same results):
select
max(case when grp = 0 then dataText end) shortData,
max(case when grp = 1 then dataText end) longData
from (
select
dataText,
grp,
row_number() over(partition by grp order by dataText) rn
from (
select distinct
case when len(dataText) <= 13 then 0 else 1 end grp,
substring(dataText, 1, 13) dataText
from mytable
) t
) t
group by rn
Demo on DB Fiddle:
shortData | longData
:---------- | :------------
1 DEC20 DDD | 1 JUL20 DDD80
1 JAN21 DDD | 1 JUL20DDDD40
1 JUL20 DDD | 1 JUL20DDDD80
null | 1 JUN20 DDD50
null | 1 JUN20DDDD50
Consider the following dataset:
+---------------------+
| ID | NAME | VALUE |
+---------------------+
| 1 | a | 0.2 |
| 1 | b | 8 |
| 1 | c | 3.5 |
| 1 | d | 2.2 |
| 2 | b | 4 |
| 2 | c | 0.5 |
| 2 | d | 6 |
| 3 | a | 2 |
| 3 | b | 4 |
| 3 | c | 3.6 |
| 3 | d | 0.2 |
+---------------------+
I'm tying to develop a sql select statement that returns the top or distinct ID where NAME 'a' and 'b' both exist and both of the corresponding VALUE's are >= '1'. Thus, the desired output would be:
+---------------------+
| ID | NAME | VALUE |
+---------------------+
| 3 | a | 2 |
+----+-------+--------+
Appreciate any assistance anyone can provide.
You can try to use MIN window function and some condition to make it.
SELECT * FROM (
SELECT *,
MIN(CASE WHEN NAME = 'a' THEN [value] end) OVER(PARTITION BY ID) aVal,
MIN(CASE WHEN NAME = 'b' THEN [value] end) OVER(PARTITION BY ID) bVal
FROM T
) t1
WHERE aVal >1 and bVal >1 and aVal = [Value]
sqlfiddle
This seems like a group by and having query:
select id
from t
where name in ('a', 'b')
having count(*) = 2 and
min(value) >= 1;
No subqueries or joins are necessary.
The where clause filters the data to only look at the "a" and "b" records. The count(*) = 2 checks that both exist. If you can have duplicates, then use count(distinct name) = 2.
Then, you want the minimum value to be 1, so that is the final condition.
I am not sure why your desired results have the "a" row, but if you really want it, you can change the select to:
select id, 'a' as name,
max(case when name = 'a' then value end) as value
you can use in and sub-query
select top 1 * from t
where t.id in
(
select id from t
where name in ('a','b')
group by id
having sum(case when value>1 then 1 else 0)>=2
)
order by id
I'm trying to find an efficient way to derive the column Expected below from only Id and State. What I want is for the number Expected to increase each time State is 0 (ordered by Id).
+----+-------+----------+
| Id | State | Expected |
+----+-------+----------+
| 1 | 0 | 1 |
| 2 | 1 | 1 |
| 3 | 0 | 2 |
| 4 | 1 | 2 |
| 5 | 4 | 2 |
| 6 | 2 | 2 |
| 7 | 3 | 2 |
| 8 | 0 | 3 |
| 9 | 5 | 3 |
| 10 | 3 | 3 |
| 11 | 1 | 3 |
+----+-------+----------+
I have managed to accomplish this with the following SQL, but the execution time is very poor when the data set is large:
WITH Groups AS
(
SELECT Id, ROW_NUMBER() OVER (ORDER BY Id) AS GroupId FROM tblState WHERE State=0
)
SELECT S.Id, S.[State], S.Expected, G.GroupId FROM tblState S
OUTER APPLY (SELECT TOP 1 GroupId FROM Groups WHERE Groups.Id <= S.Id ORDER BY Id DESC) G
Is there a simpler and more efficient way to produce this result? (In SQL Server 2012 or later)
Just use a cumulative sum:
select s.*,
sum(case when state = 0 then 1 else 0 end) over (order by id) as expected
from tblState s;
Other method uses subquery :
select *,
(select count(*)
from table t1
where t1.id < t.id and state = 0
) as expected
from table t;
Let's assume I have a report that displays an ID and VALUE from different tables
| ID | VALUE |
|----|-------|
1 | 1 | 1 |
2 | 1 | 0 |
3 | 1 | 1 |
4 | 2 | 0 |
5 | 2 | 0 |
My goal is to display this table with grouped IDs and VALUEs. My rule to grouping VALUEs would be "If VALUE contains atleast one '1' then display '1' otherwise display '0'".
My current SQL is (simplified)
SELECT
TABLE_A.ID,
CASE
WHEN TABLE_B.VALUE = 1 OR TABLE_C.VALUE NOT IN (0,1,2,3)
THEN 1
ELSE 0
END AS VALUE
FROM TABLE_A, TABLE_B, TABLE_C
GROUP BY
TABLE_A.ID
(CASE
WHEN TABLE_B.VALUE = 1 OR TABLE_C.VALUE NOT IN (0,1,2,3)
THEN 1
ELSE 0
END)
The output is following
| ID | VALUE |
|----|-------|
1 | 1 | 1 |
2 | 1 | 0 |
3 | 2 | 0 |
Which is half way to the output I want
| ID | VALUE |
|----|-------|
1 | 1 | 1 |
2 | 2 | 0 |
So my Question is: How do I extend my current SQL (or change it completely) to get my desired output?
If you are having only 0 and 1 as distinct values in FOREIGN_VALUE column then using max() function as mentioned by HoneyBadger in the comment will fulfill your requirement.
SELECT
ID,
MAX(FOREIGN_VALUE) AS VALUE
FROM (SELECT
ID,
CASE WHEN FOREIGN_VALUE = 1
THEN 1
ELSE 0
END AS FOREIGN_VALUE
FROM TABLE,
FOREIGN_TABLE)
GROUP BY
ID;
Assuming value is always 0 or 1, you can do:
select id, max(value) as value
from t
group by id;
If value can take on other values:
select id,
max(case when value = 1 then 1 else 0 end) as value
from t
group by id;
select top 20 *
from dbo.DUTs D
inner join dbo.Statuses S on d.StatusID = s.StatusID
where s.Description = 'Active'
Above SQL Query returns the top 20 rows, how can I get a nth row from the result of the above query? I looked at previous posts on finding the nth row and was not clear to use it for my purpose.
Thanks.
The row order is arbitrary, so I would add an ORDER BY expression. Then, you can do something like this:
SELECT TOP 1 * FROM (SELECT TOP 20 * FROM ... ORDER BY d.StatusID) AS d ORDER BY d.StatusID DESC
to get the 20th row.
You can also use OFFSET like:
SELECT * FROM ... ORDER BY d.StatusID OFFSET 19 ROWS FETCH NEXT 1 ROWS ONLY
And a third option:
SELECT * FROM (SELECT *, rownum = ROW_NUMBER() OVER (ORDER BY d.StatusID) FROM ...) AS a WHERE rownum = 20
I tend to use CTEs with the ROW_NUMBER() function to get my lists numbered in order. As #zambonee said, you'll need an ORDER BY clause either way or SQL can put them in a different order every time. It doesn't usually, but without ordering it yourself, you're not guaranteed to get the same thing twice. Here I'm assuming there's a [DateCreated] field (DATETIME NOT NULL DEFAULT GETDATE()), which is usually a good idea so you know when that record was entered. This says "give me everything in that table and add a row number with the most recent record as #1":
; WITH AllDUTs
AS (
SELECT *
, DateCreatedRank = ROW_NUMBER() OVER(ORDER BY [DateCreated] DESC)
FROM dbo.DUTs D
INNER JOIN dbo.Statuses S ON D.StatusID = S.StatusID
WHERE S.Description = 'Active'
)
SELECT *
FROM AllDUTs
WHERE AllDUTs.DateCreatedRank = 20;
SELECT * FROM (SELECT * FROM EMP ORDER BY ROWID DESC) WHERE ROWNUM<11
It's another sample:
SELECT * ,CASE WHEN COUNT(0)OVER() =ROW_NUMBER()OVER(ORDER BY number) THEN 1 ELSE 0 END IsNth
FROM (
select top 10 *
from master.dbo.spt_values AS d
where d.type='P'
) AS t
+------+--------+------+-----+------+--------+-------+
| name | number | type | low | high | status | IsNth |
+------+--------+------+-----+------+--------+-------+
| NULL | 0 | P | 1 | 1 | 0 | 0 |
| NULL | 1 | P | 1 | 2 | 0 | 0 |
| NULL | 2 | P | 1 | 4 | 0 | 0 |
| NULL | 3 | P | 1 | 8 | 0 | 0 |
| NULL | 4 | P | 1 | 16 | 0 | 0 |
| NULL | 5 | P | 1 | 32 | 0 | 0 |
| NULL | 6 | P | 1 | 64 | 0 | 0 |
| NULL | 7 | P | 1 | 128 | 0 | 0 |
| NULL | 8 | P | 2 | 1 | 0 | 0 |
| NULL | 9 | P | 2 | 2 | 0 | 1 |
+------+--------+------+-----+------+--------+-------+