I am aiming to produce code that generates an independent total check. As per the below table:
column1 Column2 Column3 value independent total check
A B C 10 Null
A B E 11 Null
A B total 21 21
x y z 10 Null
x y p 20 Null
x y total 30 30
I am trying to employ a conditional sum, but with no success! What I have at the moment is:
IF OBJECT_ID('tempdb..#Temp') IS NOT NULL DROP Table #Temp
select t2.Column1, t2.Column2, t2.Column3,t2.value, independanttotal =
case
when t2.Column1 ='A' and t2.Column2= 'B'and t2.T_subdesk = 'Total' then sum(t2.value)
when t2.Column1 ='x' and t2.Column2= 'y'and t2.T_subdesk = 'Total' then sum(t2.value)
end
into #Temp
from #Temp_A t2
group by t2.Column1,t2.Column2,t2.Column3,t2.value
but this is clearly incorrect, although it produces the correct result actually I am just reproducing the total value. Do I need some kind of nested sum? Do I need to separate out this into different table? this is really frustrating me
thanks for your help in advance!
You seem to want:
select t.*,
sum(case when column3 <> 'total' then value end) over (partition by column1, column2) as independent_total
from #temp t;
This puts the computation on all rows. I don't think that is a problem, but you can use a case expression outside the sum() if that is really an issue.
If you only want this on the "total" row, you can do:
select t.*,
(case when column3 = 'total'
then sum(case when column3 <> 'total' then value end) over (partition by column1, column2)
end) as independent_total
from #temp t;
Or, you slightly simplify the logic:
select t.*,
(case when column3 = 'total'
then sum(value) over (partition by column1, column2) - value
end) as independent_total
from #temp t;
This gets the total sum for the two columns and then subtracts the value on the 'total' row.
Related
I am looking to essentially create a pivot view using PostgreSQL, such that the table below:
Column A
Column B
Happy
Sad
Sad
Happy
Happy
Sad
becomes
Count
Column A
Column B
Happy
2
1
Sad
1
2
I've been able to use case/when operators far enough such that I can see the counts under independent columns,
SELECT
COUNT(CASE WHEN column1 = 'Happy' THEN 1 END) AS column1_Happy_count,
COUNT(CASE WHEN column1 = 'Sad' THEN 1 END) AS column1_Sad_count,
COUNT(CASE WHEN column2 = 'Happy' THEN 1 END) AS column2_Happy_count,
COUNT(CASE WHEN column2 = 'Sad' THEN 1 END) AS column2_Sad_count,
COUNT(CASE WHEN column3 = 'Happy' THEN 1 END) AS column3_Happy_count,
COUNT(CASE WHEN column3 = 'Sad' THEN 1 END) AS column3_Sad_count
FROM your_table;
but am missing the step to essentially each the pair of columns vertically.
I'm unable to use extensions such as tablefunc and crosstab.
Try this:
CREATE TABLE my_table (
column_a varchar(10),
column_b varchar(10)
);
INSERT INTO my_table (column_a, column_b)
VALUES ('Happy', 'Sad'),
('Sad', 'Happy'),
('Happy', 'Sad'),
('Good', 'Bad');
WITH DataSource (col, val) AS
(
SELECT 'a', column_a
FROM my_table
UNION ALL
SELECT 'b', column_b
FROM my_table
)
SELECT uniq.val AS "Count"
,MAX(case when counts.col = 'a' then counts end) AS "Column A"
,MAX(case when counts.col = 'b' then counts end) AS "Column B"
FROM
(
SELECT DISTINCT val
FROM DataSource
) uniq
INNER JOIN
(
SELECT col
,val
,COUNT(*) counts
FROM DataSource
GROUP BY col
,val
) counts
ON uniq.val = counts.val
GROUP BY uniq.val
will give you this:
You may aggregate for ColumnA, aggregate for ColumnB then do a full join as the following:
select coalesce(A.ColumnA ,B.ColumnB) as "Count",
A.cnt as "Column A",
B.cnt as "Column B"
from
(
select ColumnA, count(*) cnt
from tbl_name
group by ColumnA
) A
full join
(
select ColumnB, count(*) cnt
from tbl_name
group by ColumnB
) B
on A.ColumnA = B.ColumnB
If the distinct values in ColumnA are the same as the distinct values of ColumnB then you can use join instead of the full join.
See demo.
My data is like below, it's in a single table
Column1 Column2
abc 100
abc 200
Now I need like below
abc 100 //here 200-100
I am banging my head on how to achieve this.
I have tried to use the row_number and then subtract using case statement like
Select
column1,
sum(
case when rownum=1
then column2
end
-
case when rownum=2
then column2
end
)
from table
group by column1
But this is giving me null.
Assuming there is no attribute which can define row ordering -
;with cte as(
select
row_number() over (order by (select null)) as IndexId,
Column1,
Column2
from #xyz
)
select sum(case when IndexID=1 then (-1 * Column2) else Column2 end), Column1
from cte
group by Column1
Input data-
declare #xyz table(Column1 varchar(10),Column2 int)
insert into #xyz
select 'abc' ,100 union all
select 'abc' ,200
Assuming you have an attribute rownum in table which is always 1 or 2 (it can be generated by some row_number() as you suggest in question, according to any order that is suitable for you)
Column1 Column2 Rownum
------------------------
abc 100 1
abc 200 2
then you can simply use
Select
column1,
sum(
case when rownum=1
then column2
else -column2
end
)
from table
group by column1
It performs a sum of the Column2 per Column1, however, in the row having rownum = 2 the Column2 value is negated. Therefore in our example you end up with 100 + (-200) = -100
You could do:
select column1, max(column2) - min(column2)
from t
group by column1;
Here is a short form of the answer above if you care:
SELECT
column1,
SUM(IIF(rownum=1,column2,-column2))
FROM table
GROUP BY column1
I am trying to write a procedure that inserts calculated table data into another table.
The problem I have is that I need each row's calculated column to be influenced by the result of the previous row's calculated column. I tried to lag the calculation itself but this does not work!
Such as:
(Max is a function I created that returns the highest of two values)
Id Product Model Column1 Column2
1 A 1 5 =MAX(Column1*2, Lag(Column2))
2 A 2 2 =MAX(Column1*2, Lag(Column2))
3 B 1 3 =MAX(Column1*2, Lag(Column2))
If I try the above in SQL:
SELECT
Column1,
MyMAX(Column1,LAG(Column2, 1, 0) OVER (PARTITION BY Product ORDER BY Model ASC) As Column2
FROM Source
...it says column2 is unknown.
Output I get if I LAG the Column2 calculation:
Select Column1, MyMAX(Column1,LAG(Column1*2, 1, 0) OVER (PARTITION BY Product ORDER BY Model ASC) As Column2
Id Column1 Column2
1 5 10
2 2 10
3 3 6
Why 6 on row 3? Because 3*2 > 2*2.
Output that I want:
Id Column1 Column2
1 5 10
2 2 10
3 3 10
Why 10 on row 3? Because previous result of 10 > 3*2
The problem is I can't lag the result of Column2 - I can only lag other columns or calculations of them!
Is there a technique of achieving this with LAG or must I use Recursive CTE? I read that LAG succeeds CTE so I assumed it would be possible. If not, what would this 'CTE' look like?
Edit: Or alternatively - what else could I do to resolve this calculation?
Edit
In hindsight, this problem is a running partitioned maximum over Column1 * 2. It can be done as simply as
SELECT Id, Column1, Model, Product,
MAX(Column1 * 2) OVER (Partition BY Model, Product Order BY ID ASC) AS Column2
FROM Table1;
Fiddle
Original Answer
Here's a way to do this with a recursive CTE, without LAG at all, by joining on incrementing row numbers. I haven't assumed that your Id is contiguous, hence have added an additional ROW_NUMBER(). You haven't mentioned any partitioning, so haven't applied same. The query simply starts at the first row, and then projects the greater of the current Column1 * 2, or the preceding Column2
WITH IncrementingRowNums AS
(
SELECT Id, Column1, Column1 * 2 AS Column2,
ROW_NUMBER() OVER (Order BY ID ASC) AS RowNum
FROM Table1
),
lagged AS
(
SELECT Id, Column1, Column2, RowNum
FROM IncrementingRowNums
WHERE RowNum = 1
UNION ALL
SELECT i.Id, i.Column1,
CASE WHEN (i.Column2 > l.Column2)
THEN i.Column2
ELSE l.Column2
END,
i.RowNum
FROM IncrementingRowNums i
INNER JOIN lagged l
ON i.RowNum = l.RowNum + 1
)
SELECT Id, Column1, Column2
FROM lagged;
SqlFiddle here
Edit, Re Partitions
Partitioning is much the same, by just dragging the Model + Product columns through, then partitioning by these in the row numbering (i.e. starting back at 1 each time the Product or Model resets), including these in the CTE JOIN condition and also in the final ordering.
WITH IncrementingRowNums AS
(
SELECT Id, Column1, Column1 * 2 AS Column2, Model, Product,
ROW_NUMBER() OVER (Partition BY Model, Product Order BY ID ASC) AS RowNum
FROM Table1
),
lagged AS
(
SELECT Id, Column1, Column2, Model, Product, RowNum
FROM IncrementingRowNums
WHERE RowNum = 1
UNION ALL
SELECT i.Id, i.Column1,
CASE WHEN (i.Column2 > l.Column2)
THEN i.Column2
ELSE l.Column2
END,
i.Model, i.Product,
i.RowNum
FROM IncrementingRowNums i
INNER JOIN lagged l
ON i.RowNum = l.RowNum + 1
AND i.Model = l.Model AND i.Product = l.Product
)
SELECT Id, Column1, Column2, Model, Product
FROM lagged
ORDER BY Model, Product, Id;
Updated Fiddle
I have SQL query as below:
SELECT a.ID as AID, a.Amt as AAmt
FROM
(SELECT
ID,
CASE
WHEN Col1 = 0
THEN SUM (Col2 + Col3)
ELSE 0
END AS Amt
FROM table1
GROUP BY ID, Amt) AS a
I get an error:
Invalid column name 'Amt'.
(note: this applies to the GROUP BY clause).
You cannot GROUP BY the alias,
Try
SELECT a.ID as AID, a.Amt as AAmt
FROM
(SELECT
ID,
CASE
WHEN Col1 = 0
THEN SUM (Col2 + Col3)
ELSE 0
END AS Amt
FROM table1
GROUP BY ID, Col1) AS a
If you have a look at SQL Query Order of Operations you will note the the order of operations are
1.FROM clause
2.WHERE clause
3.GROUP BY clause
4.HAVING clause
5.SELECT clause
6.ORDER BY clause
This means that the GROUP BY is processed before the SELECT, which is where you defined the alias.
This also explains why you can order by an alias.
Your query seems a bit overly complicated, and the intention doesn't fully make sense. I suspect you want conditional aggregation:
SELECT ID, SUM(CASE WHEN col1 = 0 THEN col2 + col3 ELSE 0 END)
FROM table1
GROUP BY ID;
I have data in following way....
ColumnA ColumnB
7675 22838
7675 24907
7675 NULL
I want the results in following way.....
ColumnA ColumnB
7675 2 (need total count for Not Null value)
7675 0 (need count 0 for NULL value)
SELECT ColumnA, COUNT(ColumnB) ColumnB
FROM YourTable
GROUP BY ColumnA
UNION ALL
SELECT ColumnA, 0
FROM YourTable
WHERE ColumnB IS NULL
GROUP BY ColumnA
You could introduce a calculated column indicating whether ColumnB is null or not and use it as a grouping criterion together with ColumnA:
SELECT
t.ColumnA,
ColumnB = COUNT(t.ColumnB)
FROM
dbo.YourTable AS t
CROSS APPLY
(SELECT CASE WHEN t.ColumnB IS NULL THEN 1 ELSE 0 END) AS x (SubGroup)
GROUP BY
t.ColumnA,
x.SubGroup
ORDER BY
t.ColumnA,
x.SubGroup
;
The COUNT(t.ColumnB) expression would always be NULL for a null subgroup, and for the corresponding non-null subgroup it would return the number of the non-null entries.
select columnA,
count(columnB) as non_null_count,
sum(columnB is null) as null_count
from your_table
group by ColumnA
you could easily do with a count and sum which may be faster if there are a lot of rows rather than selecting all of the rows twice with a UNION
SELECT columna, columnb, SUM(mycount)
FROM
( SELECT *, COUNT(columnb) as mycount
FROM test
GROUP BY columnb
)t
GROUP BY mycount
ORDER BY CASE WHEN mycount = 0 THEN 1 ELSE 2 END DESC;
Fiddle Demo