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I have table like
id status other columns
-- ------ -------------
1 f
2 f
3 t
4 t
5 t
6 f
Now, when I select the table I wan to add specific column and to check when status has change. The result should be something like:
id status other columns status_index
-- ------ ------------- ------------
1 f 1
2 f 1
3 t 2
4 t 2
5 t 2
6 f 3
Query should be for postgres.
with cte as (
select
*,
row_number() over(order by id) as rn1,
row_number() over(partition by status order by id) as rn2
from Table1
)
select
id, status,
dense_rank() over(order by rn1 - rn2) as status_index
from cte
order by id
sql fiddle demo
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Need to write SQL query for getting below output with the given input table:
Input Table:
Col1
1
2
3
Output:
Col1
1
2
2
3
3
3
WITH CTE(NN)AS
(
SELECT 1 UNION ALL
SELECT 2 UNION ALL
SELECT 3 UNION ALL
SELECT 4 UNION ALL
SELECT 5
)
SELECT C.NN
FROM CTE AS C
CROSS JOIN CTE C2
WHERE C2.NN<=C.NN
CTE is your input table
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I have
id value
1 12
1 15
1 17
1 22
1 22
1 23
And I need like this
id value
1 --
1 3
1 2
1 5
1 0
1 1
Could you tell me, how to achive this?
You can try the below -
select id,
value-max(value) over(order by id rows between 1 preceding and 1 preceding) as value
from tablename
You seem to want lag(), which I'm guessing is per id and based on the ordering of value:
select t.*,
(value - lag(value) over (partition by id order by value)) as diff
from t
order by value;
That said, your sample data has exact duplicates. That is unusual in a SQL table.
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Populate sequence by group in sql server:
Input:-
ID data
1 0
1 0
1 0
2 0
2 0
2 0
Output:-
ID data
1 0
1 1
1 2
2 0
2 1
2 2
As it stands, per your sample data, you need to use ROW_NUMBER() along with partitioning.
SELECT ID, ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID) as DATA
FROM <table>
But because the ID column is not unique, the ORDER BY will not know how to discern between the first row with 1 and the third row with 1.
Which is why, I recommend in the ORDER BY ID part, to also add a unique/primary key column which will give you a deterministic order, so that you can always determine what value a certain row will have, in a fixed set of data.
So, if your table also contains a "PK" (primary key) or unique column:
PK ID data
1 1 0
2 1 1
3 1 2
4 2 0
5 2 1
6 2 2
then your select can turn into:
SELECT ID, ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID, PK) as DATA
FROM <table>
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I have a table named COURSE another table STUDENT.
COURSE_ID COURSE_NAME STUDENT_ID
1 HISTORY 11
2 BIOLOGY 11
3 BOTNY 11
STUDENT_ID STUDENT_NAME
11 AAA
22 BBB
33 CCC
Now i have to write a SQL query which returns result as below,
STUDENT_ID COURSE_NAME_1 COURSE_NAME_2 COURSE_NAME_3
11 HISTORY BIOLOGY BOTNY
Help me how to write a oracle sql query for this.how do i iterate the course name for the corresponding students.
This is a pivot query, but you want the courses enumerated. You can use row_number() to enumerate the values and then conditional aggregation to put the values in separate columns:
select student_id,
max(case when seqnum = 1 then course_name end) as course_1,
max(case when seqnum = 2 then course_name end) as course_2,
max(case when seqnum = 3 then course_name end) as course_3
from (select c.*, row_number() over (partition by student_id order by course_id) as seqnum
from course c
) c
group by student_id;
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This might be SQL 101, but it's stumping me.
I have data like this:
ID ZipCode Value
1 12345 1
2 12346 Null
3 12347 Null
4 12348 2
5 12349 3
6 12350 Null
7 12351 Null
8 12352 4
I need a way to update records that have a null 'value' is updated to the NEXT available value.
ie:
ID ZipCode Value
1 12345 1
2 12346 2
3 12347 2
4 12348 2
5 12349 3
6 12350 4
7 12351 4
8 12352 4
I think this can be done easily enough with a cursor, but there has to be a better way.
There is no need to use cursor.
Updating the table in a single statement can be tricky.
So for safety I would first get the result set with the values to assign for all NULL values:
WITH B AS
(
SELECT ID, (SELECT MIN(Value)
FROM MyTable
WHERE ID > A.ID AND MyTable.Value IS NOT NULL) ValueToAssign
FROM MyTable A
WHERE Value IS NULL
)
UPDATE MyTable
SET Value = B.ValueToAssign
FROM MyTable JOIN B ON MyTable.ID = B.ID
It works if there are gaps between ID.
Here's a Demo on SqlFiddle.
;with cte
as
(
select ID, ZipCode, Value, ROW_NUMBER() OVER(ORDER BY ID) rn
from tb o
)
, ct
as
(
select top 1 *
from cte
order by rn desc
union all
select t.ID, t.ZipCode,
case when t.Value is null then o.Value else t.Value end 'Value', t.rn
from cte t inner join ct o on t.rn = o.rn - 1
)
update tb
set Value = ct.Value
from tb inner join ct on tb.ID = ct.ID
where tb.Value is null