Please consider this result set:
Name Value1 Value2 Value3
---------------------------------------
ccc 1 2 3
aaa 3 4 3
bbb 2 8 5
Group 1 2 1 3
rrr 1 2 5
mmm 3 4 4
nnn 3 2 1
eee 2 6 5
Group 2 2 4 4
...
As you see the record in each group don't sorted in alphabetically order. How I can sort record in each group alphabetically?
The desired result set is:
Name Value1 Value2 Value3
---------------------------------------
aaa 3 4 3
bbb 2 8 5
ccc 1 2 3
Group 1 2 1 3
eee 2 6 5
mmm 3 4 4
nnn 3 2 1
rrr 1 2 5
Group 2 2 4 4
...
EDIT 1)
Code for generat base result set:
DECLARE #tbl AS Table
(
Name NVARCHAR(50),
Value1 DECIMAL(5,2),
Value2 DECIMAL(5,2),
Value3 DECIMAL(5,2)
)
INSERT INTO #tbl VALUES('ccc',1,2,3)
INSERT INTO #tbl VALUES('aaa',3,4,3)
INSERT INTO #tbl VALUES('bbb',2,8,5)
INSERT INTO #tbl VALUES('Group 1',2,1,3)
INSERT INTO #tbl VALUES('rrr',1,2,5)
INSERT INTO #tbl VALUES('mmm',3,4,4)
INSERT INTO #tbl VALUES('nnn',3,2,1)
INSERT INTO #tbl VALUES('Group 2',2,4,4)
select * from #tbl
Try this:
select * from (
select Name, value1, value2, value3,
case when Name like 'group%' then SUM(Groups) over (order by (select null) rows between unbounded preceding and current row) - 1
else SUM(Groups) over (order by (select null) rows between unbounded preceding and current row) end [groupingCol],
groups
from (
select *,
case when Name like 'group%' then 1 else 0 end [Groups] from #tbl
) a
) b order by groupingCol, Groups, name
Related
I have the following table:
RowID Column1 Column2
1 3 2
2 5 2
3 2 9
4 5 NULL
5 8 NULL
6 9 3
7 1 NULL
I need first row of Column1 to Sum every time there is a NULL value in Column2. And it would continue the logic down the rows.
So, the result should look like:
RowID Column1 Column2
1 3 2
2 5 2
3 15 9
4 5 NULL
5 8 NULL
6 10 3
7 1 NULL
Notice Row 3 summed 2+5+8 =15 and Row 6 summed 9+1 =10. So, basically the row prior to Null value in Column2 summed the values in column1 until there was no more NULL values in column2. Then it resumed in row 6 where the next value was NULL.
This will do it. I have set up the data in a table variable for demo.
declare #t table(RowID int, C1 int, C2 int)
insert #t values (1, 3, 2)
,(2, 5, 2)
,(3, 2, 9)
,(4, 5, NULL)
,(5, 8, NULL)
,(6, 9, 3)
,(7, 1, NULL)
select RowID, sum(C1), max(C2)
from (
select RowID, C1, C2 from #t
union all
select T1.RowID, T2.C1, null
from #t t1
join #t t2 on t2.RowID>t1.RowID and t2.C2 is null
and not exists(
select * from #t t3
where t3.RowID>t1.RowID and t3.c2 is not null and t3.RowID<t2.RowID
)
where T1.C2 is not null
) q group by RowID
Result:
RowID C1 C2
1 3 2
2 5 2
3 15 9
4 5 NULL
5 8 NULL
6 10 3
7 1 NULL
I got it. You need to look at the rows in reverse order, assigning the NULL values to the value before them.
The idea is to assign a group to the rows to sum. This is the number of non-NULL values following the row. With this, you can then use a window function to aggregate:
select t.*,
(case when c2 is null then c1
else sum(c1) over (partition by grp)
end) as new_c1
from (select t.*, count(c2) over (order by rowid rows between 1 following and unbounded following) as grp
from t
) t
order by rowid;
Here is a db<>fiddle.
I have requirement to update column3 of following table by cross checking the value of value2 with next row of value1
If equal then value3 = value1*value2 and if not value3 = value1
CREATE TABLE #tmpValue1(id INT IDENTITY(1,1), value1 FLOAT, value2 FLOAT, value3 FLOAT)
INSERT INTO #tmpValue1(value1, value2) VALUES
(1, 2), (2,3), (3,4), (4,5),(6,7),(7,8),(8,9)
Table #tmpValue1 will be as:
id value1 value2 value3 (expected output)
1 1 2 1
2 2 3 4
3 3 4 9
4 4 5 16
5 6 7 6
6 7 8 49
7 8 9 64
Above, in value3 updated with 1 in first because 2 of Value2 row first is comparing to 2 of value1 of row second so it will start updating with second.
Note: Value1 and Value2 is just sample and is real it can be different.
We can simply do it by using LEFT JOIN as below:
UPDATE t1 SET t1.value3 = (ISNULL(t2.value2,1) * t1.value1)
FROM #tmpValue1 t1
LEFT JOIN #tmpValue1 t2 ON t1.id = t2.id+1
AND t1.value1 = t2.value2
We should use id which is identity column and is beneficial for performing such an operation.
You can use LAG... though your expected output seems to have some errors in it.
select
ID,
Value1,
Value2,
case
when lag(value2) over (order by ID) = value1 then lag(value2) over (order by ID) * value1
else value1 end as Value3
from #tmpValue1
RESULTS
ID Value1 Value2 Value3
1 1 2 1
2 2 3 4
3 3 4 9
4 4 5 16
5 6 7 6
6 7 8 49
7 8 9 64
I have a table that contains 3 columns as below:
col1 col2 col3
---- ---- ----
1 1 null
2 2 null
3 3 null
4 1 null
5 1 null
6 1 null
7 2 null
ETC
I need to update a third column in the same table as follows:
col1 col2 col3
---- ---- ----
1 1 1
2 2 1
3 3 1
4 1 2
5 1 3
6 1 4
7 2 4
The logic behind the update is that each time the 2nd column contains a 1 in it, the third has to increment. The first column is just a sequential integer column.
You can use the row_number analytical function to number the rows with col2 = 1 sequentially and then use a subquery to find to closest value with a lower col1 for the other rows.
So given a test table like this:
create table t (c1 int, c2 int, c3 int);
insert t (c1, c2) values
(1, 1),
(2, 2),
(3, 3),
(4, 1),
(5, 1),
(6, 1),
(7, 2);
A query like this:
;with cte as (
select t.c1, t.c2, x.c3
from t
left join (
select c1, c2, row_number() over (partition by c2 order by c1) c3
from t
where c2 = 1
) x on t.c1 = x.c1
)
update t
set t.c3 = coalesce(cte1.c3,(select max(cte2.c3) from cte cte2 where cte2.c1 < cte1.c1))
from cte cte1
where t.c1 = cte1.c1
Will give the following result:
c1 c2 c3
1 1 1
2 2 1
3 3 1
4 1 2
5 1 3
6 1 4
7 2 4
Another, possibly faster, way to do this would be:
update t1 set c3 = (select count(*) from t where c2 = 1 and c1 <= t1.c1) from t t1
I would like create a query in MS-SQL to make a column containing an incrementing group number.
This is how I want my data to return:
Column 1 | Column 2 | Column 3
------------------------------
I | 1 | 1
O | 2 | 2
O | 2 | 3
I | 3 | 4
O | 4 | 5
O | 4 | 6
O | 4 | 7
O | 4 | 8
I | 5 | 9
O | 6 | 10
Column 1 is the I and O meaning In and Out.
Column 2 is the row Group (this should increment when Column 1 changes).
Column 3 is the Row-number.
So how can I write my query so that Column 2 increments every time Column 1 changes?
Firstly, to perform this kind of operation you need some column that can identify the order of the rows. If you have a column that determines this order, an identity column for example, it can be used to do something like this:
Runnable sample:
CREATE TABLE #Groups
(
id INT IDENTITY(1, 1) , -- added identity to provide order
Column1 VARCHAR(1)
)
INSERT INTO #Groups
( Column1 )
VALUES ( 'I' ),
( 'O' ),
( 'O' ),
( 'I' ),
( 'O' ),
( 'O' ),
( 'O' ),
( 'O' ),
( 'I' ),
( 'O' );
;
WITH cte
AS ( SELECT id ,
Column1 ,
1 AS Column2
FROM #Groups
WHERE id = 1
UNION ALL
SELECT g.id ,
g.Column1 ,
CASE WHEN g.Column1 = cte.Column1 THEN cte.Column2
ELSE cte.Column2 + 1
END AS Column2
FROM #Groups g
INNER JOIN cte ON cte.id + 1 = g.id
)
SELECT *
FROM cte
OPTION (MAXRECURSION 0) -- required to allow for more than 100 recursions
DROP TABLE #Groups
This code effectively loops through the records, comparing each row to the next and incrementing the value of Column2 if the value in Column1 changes.
If you don't have an identity column, then you might consider adding one.
Credit #AeroX:
With 30K records, the last line: OPTION (MAXRECURSION 0) is required to override the default of 100 recursions when using a Common Table Expression (CTE). Setting it to 0, means that it isn't limited.
This will work if you have sqlserver 2012+
DECLARE #t table(col1 char(1), col3 int identity(1,1))
INSERT #t values
('I'), ('O'), ('O'), ('I'), ('O'), ('O'), ('O'), ('O'), ('I'), ('O')
;WITH CTE AS
(
SELECT
case when lag(col1) over (order by col3) = col1
then 0 else 1 end increase,
col1,
col3
FROM #t
)
SELECT
col1,
sum(increase) over (order by col3) col2,
col3
FROM CTE
Result:
col1 col2 col3
I 1 1
O 2 2
O 2 3
I 3 4
O 4 5
O 4 6
O 4 7
O 4 8
I 5 9
O 6 10
I have the following table:
ID | X
1 | 1
2 | 2
3 | 5
4 | 6
5 | 7
6 | 9
I need to enumerate groups of rows in such way that if row i and i-1 differ in column X by less than 2 they should have the same group number N. See example below.
ID | X | N
1 | 1 | 1
2 | 2 | 1
3 | 5 | 2
4 | 6 | 2
5 | 7 | 2
6 | 9 | 3
Note that rows X(2)-X(1)=1 so they are grouped in the first group. Than X(3)-X(2)=3 so the 3rd row goes to 2nd group with 3rd and 4th row. X(6)-X(5)=2 so 6th row is in the 3rd group.
Can anybody help me with writing SQL query that will return the second table?
This should do it:
select id, x, sum(new_group) over (order by id) as group_no
from
( select id, x, case when x-prev_x = 1 then 0 else 1 end new_group
from
( select id, x, lag(x) over (order by id) prev_x
from mytable
)
);
I get the correct answer for your data with that query.
SQL> create table mytable (id,x)
2 as
3 select 1, 1 from dual union all
4 select 2, 2 from dual union all
5 select 3, 5 from dual union all
6 select 4, 6 from dual union all
7 select 5, 7 from dual union all
8 select 6, 9 from dual
9 /
Table created.
SQL> select id
2 , x
3 , sum(y) over (order by id) n
4 from ( select id
5 , x
6 , case x - lag(x) over (order by id)
7 when 1 then 0
8 else 1
9 end y
10 from mytable
11 )
12 order by id
13 /
ID X N
---------- ---------- ----------
1 1 1
2 2 1
3 5 2
4 6 2
5 7 2
6 9 3
6 rows selected.
Which is essentially the same as Tony's answer, only one inline view less.
Regards,
Rob.
Using basic operations only:
create table test(id int, x int);
insert into test values(1, 1), (2, 2), (3, 5), (4, 6), (5, 7), (6, 9);
create table temp as
select rownum() r, 0 min, x max
from test t
where not exists(select * from test t2 where t2.x = t.x + 1);
update temp t set min = select max + 1 from temp t2 where t2.r = t.r - 1;
update temp t set min = 0 where min is null;
select * from temp order by r;
select t.id, t.x, x.r from test t, temp x where t.x between x.min and x.max;
drop table test;
drop table temp;