I have table like this
|-------------------------|
| A | B | C |
|-------------------------|
| 1 | 2 | 5 |
|-------------------------|
| 1 | 2 | 10 |
|-------------------------|
| 1 | 2 | 2 |
|-------------------------|
I need to delete all duplicated rows with equals A nad B value and lower C value
after running sql script i need to have only this row with top C Value for every equals A and B columns
|-------------------------|
| A | B | V |
|-------------------------|
| 1 | 2 | 10 |
|-------------------------|
One method is window functions:
select t.*
from (select t.*,
row_number() over (partition by a, b order by v desc) as seqnum
from t
) t
where seqnum = 1;
This returns the entire row, which can be handy if you want additional columns. If you really need just the three columns, then aggregation does what you want:
select a, b, max(v)
from t
group by a, b;
In standard SQL, you can keep only the maximum value using:
delete from t
where t.v < (select max(t2.v) from t t2 where t2.a = t.a and t2.b = t.b);
Original Table
Id | Time | Status
------------------
1 | 5 | T
1 | 6 | F
2 | 3 | F
1 | 2 | F
2 | 4 | T
3 | 7 | F
2 | 3 | T
3 | 1 | F
4 | 7 | H
4 | 6 | S
4 | 5 | F
4 | 4 | T
5 | 5 | S
5 | 6 | F
Expected Table
Id | Time | Status
------------------
1 | 6 | F
3 | 7 | F
4 | 5 | F
I want all the distinct ids who have status as F but time should be maximum, if for any id status is T for given maximum time then that id should not be picked. Also only those ids should be picked who have at-least one T. For e.g 4 will not be picked at it doesn't have any 'T' as status.
Please help in writing the SQL query.
You can use EXISTS and NOT EXISTS in the WHERE clause:
select t.*
from tablename t
where t.status = 'F'
and exists (select 1 from tablename where id = t.id and status = 'T')
and not exists (
select 1
from tablename
where id = t.id and status in ('F', 'T') and time > t.time
)
See the demo.
Results:
| Id | Time | Status |
| --- | ---- | ------ |
| 1 | 6 | F |
| 4 | 5 | F |
Try the below way -
select * from tablename t
where time = (select max(time) from tablename t1 where t.id=t1.id and Status='F')
and Status='F'
the following should work
select id,max(time) as time,status
from table
where status='F'
group by id,status
select id, max(time), status
from stuff s
where status = 'F'
and id not in (
select id
from stuff s2
where s2.id = s.id
and s2.time > s.time
and s2.status = 'T')
group by id, status;
You can see the Fiddle here.
As I understand it, you want to find the highest time for each ID (max(time)) where the status is F, but only if there isn't a later record where the status is 'T'. The sub query filters out records where there exists a later record where the status is T.
WITH MAX_TIME_ID AS (
SELECT
ID
,MAX(TIME) AS MAX_TIME
GROUP BY
ID
)
SELECT
O.*
FROM
ORIGINAL_TABLE O
INNER JOIN
MAX_TIME_ID MAX
ON
O.ID = MAX.ID
WHERE
O.STATUS = 'F'
The CTE will find the max time for each ID and the inner join with the where clause on the status will select it only if the latest is 'F'.
I would just use window functions:
select t.*
from (select t.*
row_number() over (partition by id order by time desc) as seqnum,
sum(case when status = 'T' then 1 else 0 end) over (partition by id) as num_t
from t
) t
where num_t > 0 and
seqnum = 1 and status = 'F';
There is a another fun way to do this just with aggregation:
select id, max(time) as time, 'F' as status
from t
group by id
having sum(case when status = 'T' then 1 else 0 end) > 0 and
max(time) = max(case when status 'F' then time end);
Assume I have this table:
+----+-------+
| id | value |
+----+-------+
| 1 | 5 |
| 2 | 4 |
| 3 | 1 |
| 4 | NULL |
| 5 | NULL |
| 6 | 14 |
| 7 | NULL |
| 8 | 0 |
| 9 | 3 |
| 10 | NULL |
+----+-------+
I want to write a query that will replace any NULL value with the last value in the table that was not null in that column.
I want this result:
+----+-------+
| id | value |
+----+-------+
| 1 | 5 |
| 2 | 4 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 14 |
| 7 | 14 |
| 8 | 0 |
| 9 | 3 |
| 10 | 3 |
+----+-------+
If no previous value existed, then NULL is OK. Ideally, this should be able to work even with an ORDER BY. So for example, if I ORDER BY [id] DESC:
+----+-------+
| id | value |
+----+-------+
| 10 | NULL |
| 9 | 3 |
| 8 | 0 |
| 7 | 0 |
| 6 | 14 |
| 5 | 14 |
| 4 | 14 |
| 3 | 1 |
| 2 | 4 |
| 1 | 5 |
+----+-------+
Or even better if I ORDER BY [value] DESC:
+----+-------+
| id | value |
+----+-------+
| 6 | 14 |
| 1 | 5 |
| 2 | 4 |
| 9 | 3 |
| 3 | 1 |
| 8 | 0 |
| 4 | 0 |
| 5 | 0 |
| 7 | 0 |
| 10 | 0 |
+----+-------+
I think this might involve some kind of analytic function - somehow partitioning over the value column - but I'm not sure where to look.
You can use a running sum to set groups and use max to fill in the null values.
select id,max(value) over(partition by grp) as value
from (select id,value,sum(case when value is not null then 1 else 0 end) over(order by id) as grp
from tbl
) t
Change the over() clause to order by value desc to get the second result in the question.
The best way has been covered by Itzik Ben-Gan here:The Last non NULL Puzzle
Below is a solution which for 10 million rows and completes around in 20 seconds on my system
SELECT
id,
value1,
CAST(
SUBSTRING(
MAX(CAST(id AS binary(4)) + CAST(value1 AS binary(4)))
OVER (ORDER BY id
ROWS UNBOUNDED PRECEDING),
5, 4)
AS int) AS lastval
FROM dbo.T1;
This solution assumes your id column is indexed
You can also try using correlated subquery
select id,
case when value is not null then value else
(select top 1 value from table
where id < t.id and value is not null order by id desc) end value
from table t
Result :
id value
1 5
2 4
3 1
4 1
5 1
6 14
7 14
8 0
9 3
10 3
If the NULLs are scattered I use a WHILE loop to fill them in
However if the NULLs are in longer consecutive strings there are faster ways to do it.
So here's one approach:
First find a record that we want to update. It has NULL in this record and no NULL in the prior record
SELECT C.VALUE, N.ID
FROM TABLE C
INNER JOIN TABLE N
ON C.ID + 1 = N.ID
WHERE C.VALUE IS NOT NULL
AND N.VALUE IS NULL;
Use that to update: (bit hazy on this syntax but you get the idea)
UPDATE N
SET VALUE = C.Value
FROM TABLE C
INNER JOIN TABLE N
ON C.ID + 1 = N.ID
WHERE C.VALUE IS NOT NULL
AND N.VALUE IS NULL;
.. now just keep doing it till you run out of rows
-- This is needed to set ##ROWCOUNT to non zero
SELECT 1;
WHILE ##ROWCOUNT <> 0
BEGIN
UPDATE N
SET VALUE = C.Value
FROM TABLE C
INNER JOIN TABLE N
ON C.ID + 1 = N.ID
WHERE C.VALUE IS NOT NULL
AND N.VALUE IS NULL;
END
The other way is to use a similiar query to get a range of id's to update. This works much faster if your NULLS are usually against consecutive id's
Here is the one simple approach using OUTER APPLY
CREATE TABLE #table(id INT, value INT)
INSERT INTO #table VALUES
(1,5),
(2,4),
(3,1),
(4,NULL),
(5,NULL),
(6,14),
(7,NULL),
(8,0),
(9,3),
(10,NULL)
SELECT t.id, ISNULL(t.value, t3.value) value
FROM #table t
OUTER APPLY(SELECT id FROM #table WHERE id = t.id AND VALUE IS NULL) t2
OUTER APPLY(SELECT TOP 1 value
FROM #table WHERE id <= t2.id AND VALUE IS NOT NULL ORDER BY id DESC) t3
OUTPUT:
id VALUE
---------
1 5
2 4
3 1
4 1
5 1
6 14
7 14
8 0
9 3
10 3
Using this sample data:
if object_id('tempdb..#t1') is not null drop table #t1;
create table #t1 (id int primary key, [value] int null);
insert #t1 values(1,5),(2,4),(3,1),(4,NULL),(5,NULL),(6,14),(7,NULL),(8,0),(9,3),(10,NULL);
I came up with:
with x(id, [value], grouper) as (
select *, row_number() over (order by id)-sum(iif([value] is null,1,0)) over (order by id)
from #t1)
select id, min([value]) over (partition by grouper)
from x;
I noticed, however, that Vamsi Prabhala beat me to it... My solution is identical to what he posted. (arghhhh!). So I thought I'd try a recursive solution. Here's a pretty efficient use of a recursive cte (provided that ID is indexed):
with sorted as (select *, seqid = row_number() over (order by id) from #t1),
firstRecord as (select top(1) * from #t1 order by id),
prev as
(
select t.id, t.[value], lastid = 1, lastvalue = null
from sorted t
where t.id = 1
union all
select t2.id, t2.[value], lastid+1, isnull(prev.[value],lastvalue)
from sorted t2
join prev on t2.id = prev.lastid+1
)
select id, [value]=isnull([value],lastvalue)--, *
from prev;
Normally I don't like recursive cte's (rCte for short) but in this case it offered an elegant solution and was faster than using the window aggregate function (sum over, min over...). Note the execution plans, the rcte on the bottom. The rCTE get's it done with two index seeks, one of which is for just one row. Unlike the window aggregate solution, the rcte does not require a sort. Running this with statistics io on; the rcte produces much less IO.
All this said, don't use either of these solutions, What the TheGameiswar posted will perform the best by far. His solution on a properly indexed id column would be lightening fast.
Following UPDATE statement can be used, please test it before use
update #table
set value = newvalue
from (
select
s.id, s.value,
(select top 1 t.value from #table t where t.id <= s.id and t.value is not null order by t.id desc) as newvalue
from #table S
) u
where #table.id = u.id and #table.value is null
stop worrying..here's the answer for you :)
SELECT *
INTO #TempIsNOtNull
FROM YourTable
WHERE value IS NOT NULL
SELECT *
INTO #TempIsNull
FROM YourTable
WHERE value IS NULL
UPDATE YourTable
SEt YourTable.value = UpdateDtls.value
FROM YourTable
JOIN (
SELECT OuterTab1.id,
#TempIsNOtNull.value
FROM #TempIsNull OuterTab1
CROSS JOIN #TempIsNOtNull
WHERE OuterTab1.id - #TempIsNOtNull.id > 0
AND (OuterTab1.id - #TempIsNOtNull.id) = ( SELECT TOP 1
OuterTab1.id - #TempIsNOtNull.id
FROM #TempIsNull InnerTab
CROSS JOIN #TempIsNOtNull
WHERE OuterTab1.id - #TempIsNOtNull.id > 0
AND OuterTab1.id = InnerTab.id
ORDER BY (OuterTab1.id - #TempIsNOtNull.id) ASC) ) AS UpdateDtls
ON (YourTable.id = UpdateDtls.id)
Given the following table structure and sample data:
+-------------+------+-------------+
| EmployeeID | Name | WorkWeek |
+--------------+-------+-----------+
| 1 | A | 1 |
| 2 | B | 1 |
| 2 | B | 2 |
| 3 | C | 1 |
| 3 | C | 2 |
| 4 | D | 2 |
+--------------+-------+-----------+
I am looking to select all employees that only worked week 1 (so in this example, only employeeid = 1 would be returned. I am able to get the data with the following query:
SELECT EmployeeId, Name
FROM SomeTable
GROUP BY EmployeeId, Name
HAVING SUM ( WorkWeek ) = 1;
To me, the HAVING SUM( WorkWeek ) = 1 is a hack and this should be handled with some form of a GROUP BY and COUNT but I cannot wrap my head around how that query would be structured.
Any help would be useful and enlightening.
HAVING SUM( WorkWeek ) = 1 may work for week 1 or 2, but will fail for week 3 (since 1+2 = 3).
Use NOT EXISTS operator with a subquery instead:
SELECT EmployeeId, Name
FROM SomeTable t1
WHERE NOT EXISTS (
SELECT * FROM SomeTable t2
WHERE t1.EmployeeId = t2.EmployeeId
AND t2.WorkWeek <> 1
)
Actually, that's exactly why the having clause is for - to filter records according to the aggregated values.
From w3schools sql tutorial:
The HAVING clause was added to SQL because the WHERE keyword could not be used with aggregate functions.
I'm trying to find the proper SQL for the following situation:
Supposed we have two tables:
TABLE A
ID int,
TEXT varchar(200)
TABLE B
ID int,
A_NO int,
B_NO int
Fields named "ID" on both tables can be join to link tables.
The following SQL:
SELECT
A.ID,
B.A_NO,
B.B_NO
FROM
A
LEFT JOIN
B
ON A.ID = B.ID
ORDER BY A.ID, B.A_NO, B.B_NO
gives the following results:
Now, the problem.
What is asked for is to have in the column B_NO a value = 1 for the MIN value of column A_NO and a value = 0 for all the others row with the same A_NO value.
The results below are expected:
Please note that, in this example, we can find two rows for each B_NO value but it is possible to have more than 2 rows.
I have tried to reproduce these results by using a CASE but with no success.
Thanks for you help in advance,
Bouzouki.
Try this using CTE and ROW_NUMBER(); (DEMO)
Please note: I have considered myT as your joined query of A and B tables for demo purpose. So replace myT with as yours A LEFT JOIN B ON A.ID = B.ID.
;with cte as (
select id, a_no, b_no,
row_number() over(partition by id,b_no order by a_no) rn
from myT
)
select id,a_no, case when rn=1 then b_no else 0 end b_no
from cte
order by a_no
--RESULTS FROM DEMO TABLE
| ID | A_NO | B_NO |
-------------------------
| 1031014 | 1 | 1 |
| 1031014 | 2 | 0 |
| 1031014 | 3 | 2 |
| 1031014 | 4 | 0 |
| 1031014 | 5 | 3 |
| 1031014 | 6 | 0 |
| 1031014 | 7 | 4 |
| 1031014 | 8 | 0 |
| 1031014 | 9 | 5 |
| 1031014 | 10 | 0 |
something like
select ID, a_no, b_no,
case when a_no = min_a_no then b_no else 0 end as new_b_no
from
a left join b on a.id = b.id left join
(Select ID, B_no, min(a_no) as min_a_no
from a left join b on a.id = b.id
group by id, b_no) m on a.id = m.id and b.b_no = m.b_no
ORDER BY A.ID, B.A_NO