How to set the first column value of a GROUPING SETS - sql

I have the following request :
SELECT column1, column2, SUM(column3) as total
FROM my_table
GROUP BY GROUPING SETS ((column1, column2), ())
Which returns :
Name1
Name2
QTT
AB
CD
15
ZE
EF
15
None
None
30
So |None|None|30 is the output from the GROUPING BY SETS
But I am wondering how to define the first None to be something else :
|SubTotal|None|30
For example.
The final output would be :
Name1
Name2
QTT
AB
CD
15
ZE
EF
15
SubTotal
None
30

The dialect is not provided, but the corresponding part to GROUPING SETS is GROUPING function:
Describes which of a list of expressions are grouped in a row produced by a GROUP BY query.
GROUPING_ID is not an aggregate function, but rather a utility function that can be used alongside aggregation, to determine the level of aggregation a row was generated for
CREATE TABLE my_table(Name1 TEXT, Name2 TEXT, QTT INT)
AS SELECT 'AB','CD',15
UNION SELECT 'ZE','EF',15;
SELECT CASE WHEN GROUPING_ID(Name1,Name2)=3THEN 'Subtotal' ELSE Name1 END AS Name1
,Name2, SUM(QTT) as total
FROM my_table
GROUP BY GROUPING SETS ((Name1, Name2), ());
Output:
Related:
SQL Server GROUPING_ID
Postgresql GROUPING
MySQL GROUPING

Related

Using IF or Case with multiple in SQL Statement

I want to do something like this
this works
Select ID, number, cost from table order by number
number can be 2-xtimes but the cost and the same
1 A33 66.50
2 A34 73.50
3 A34 73.50
But I want to have
1 A33 66.50
2 A34 73.50
3 A34 0
I want to change it in the Sql to 0
I tried distinct or if then else.
I want to do something like this
declare #oldcost int;
Select ID, number,
if(cost=#oldcost) then
cost=0;
else
cost=cost;
end if
#oldcost=cost;
from table order by number
How can I do it in SQL?
You can use window functions and a case expression:
select ID, number,
(case when row_number() over (partition by number order by id) = 1
then cost else 0
end) as cost
from table
order by number, id;
Note that SQL generally does not take ordering into account, so results can be returned in any order -- and even with an order by, rows with the same keys can be in any order (and in different orders on different executions).
Hence, the order by includes id as well as number so you get the cost on the "first" row for each number.

SQL group table by "leading rows" without pl/sql

I have this table (short example) with two columns
1 a
2 a
3 a3
4 a
5 a
6 a6
7 a
8 a8
9 a
and I would like to group/partition them into groups separated by those leading "a", ideally to add another column like this, so I can address those groups easily.
1 a 0
2 a 0
3 a3 3
4 a 3
5 a 3
6 a6 6
7 a 6
8 a8 8
9 a 8
problem is that setup of the table is dynamic so I can't use staticly lag or lead functions, any ideas how to do this without pl/sql in postgres version 9.5
Assuming the leading part is a single character. Hence the expression right(data, -1) works to extract the group name. Adapt to your actual prefix.
The solution uses two window functions, which can't be nested. So we need a subquery or a CTE.
SELECT id, data
, COALESCE(first_value(grp) OVER (PARTITION BY grp_nr ORDER BY id), '0') AS grp
FROM (
SELECT *, NULLIF(right(data, -1), '') AS grp
, count(NULLIF(right(data, -1), '')) OVER (ORDER BY id) AS grp_nr
FROM tbl
) sub;
Produces your desired result exactly.
NULLIF(right(data, -1), '') to get the effective group name or NULL if none.
count() only counts non-null values, so we get a higher count for every new group in the subquery.
In the outer query, we take the first grp value per grp_nr as group name and default to '0' with COALESCE for the first group without name (which has a NULL as group name so far).
We could use min() or max() as outer window function as well, since there is only one non-null value per partition anyway. first_value() is probably cheapest since the rows are sorted already.
Note the group name grp is data type text. You may want to cast to integer, if those are clean (and reliably) integer numbers.
This can be achieved by setting rows containing a to a specific value and all the other rows to a different value. Then use a cumulative sum to get the desired number for the rows. The group number is set to the next number when a new value in the val column is encountered and all the proceeding rows with a will have the same group number as the one before and this continues.
I assume that you would need a distinct number for each group and the number doesn't matter.
select id, val, sum(ex) over(order by id) cm_sum
from (select t.*
,case when val = 'a' then 0 else 1 end ex
from t) x
The result for the query above with the data in question, would be
id val cm_sum
--------------
1 a 0
2 a 0
3 a3 1
4 a 1
5 a 1
6 a6 2
7 a 2
8 a8 3
9 a 3
With the given data, you can use a cumulative max:
select . . .,
coalesce(max(substr(col2, 2)) over (order by col1), 0)
If you don't strictly want the maximum, then it gets a bit more difficult. The ANSI solution is to use the IGNORE NULLs option on LAG(). However, Postgres does not (yet) support that. An alternative is:
select . . ., coalesce(substr(reft.col2, 2), 0)
from (select . . .,
max(case when col2 like 'a_%' then col1 end) over (order by col1) as ref_col1
from t
) tt join
t reft
on tt.ref_col1 = reft.col1
You can also try this :
with mytable as (select split_part(t,' ',1)::integer id,split_part(t,' ',2) myvalue
from (select unnest(string_to_array($$1 a;2 a;3 a3;4 a;5 a;6 a6;7 a;8 a8;9 a$$,
';'))t) a)
select id,myvalue,myresult from mytable join (
select COALESCE(NULLIF(substr(myvalue,2),''),'0') myresult,idmin id_down
,COALESCE(lead(idmin) over (order by myvalue),999999999999) id_up
from (
select myvalue,min(id) idmin from mytable group by 1
) a) b
on id between id_down and id_up-1

SQL Query Help: Returning distinct values from Count subquery

I've been stuck for quite a while now trying to get this query to work.
Here's the setup:
I have a [Notes] table that contains a nonunique (Number) column and a nonunique (Result) column. I'm looking to create a SELECT statement that will display each distinct (Number) value where the count of the {(Number), (Result)} tuple where Result = 'NA' is > 25.
Number | Result
100 | 'NA'
100 | 'TT'
101 | 'NA'
102 | 'AM'
100 | 'TT'
200 | 'NA'
200 | 'NA'
201 | 'NA'
Basically, have an autodialer that calls a number and returns a code depending on the results of the call. We want to ignore numbers that have had an 'NA'(no answer) code returned more than 25 times.
My basic attempts so far have been similar to:
SELECT DISTINCT n1.Number
FROM Notes n1
WHERE (SELECT COUNT(*) FROM Notes n2
WHERE n1.Number = n2.Number and n1.Result = 'NA') > 25
I know this query isn't correct, but in general I'm not sure how to relate the DISTINCT n1.Number from the initial select to the Number used in the subquery COUNT. Most examples I see aren't actually doing this by adding a condition to the COUNT returned. I haven't had to touch too much SQL in the past half decade, so I'm quite rusty.
you can do it like this :
SELECT Number
FROM Notes
WHERE Result = 'NA'
GROUP BY Number
HAVING COUNT(Result) > 25
Try this:
SELECT Number
FROM (
SELECT Number, Count(Result) as CountNA
FROM Notes
WHERE Result = 'NA'
GROUP BY Number
)
WHERE CountNA > 25
EDIT: depending on SQL product, you may need to give the derived table a table correlation name e.g.
SELECT DT1.Number
FROM (
SELECT Number, Count(Result) as CountNA
FROM Notes
WHERE Result = 'NA'
GROUP
BY Number
) AS DT1 (Number, CountNA)
WHERE DT1.CountNA > 25;

Select values in SQL that do not have other corresponding values except those that i search for

I have a table in my database:
Name | Element
1 2
1 3
4 2
4 3
4 5
I need to make a query that for a number of arguments will select the value of Name that has on the right side these and only these values.
E.g.:
arguments are 2 and 3, the query should return only 1 and not 4 (because 4 also has 5). For arguments 2,3,5 it should return 4.
My query looks like this:
SELECT name FROM aggregations WHERE (element=2 and name in (select name from aggregations where element=3))
What do i have to add to this query to make it not return 4?
A simple way to do it:
SELECT name
FROM aggregations
WHERE element IN (2,3)
GROUP BY name
HAVING COUNT(element) = 2
If you want to add more, you'll need to change both the IN (2,3) part and the HAVING part:
SELECT name
FROM aggregations
WHERE element IN (2,3,5)
GROUP BY name
HAVING COUNT(element) = 3
A more robust way would be to check for everything that isn't not in your set:
SELECT name
FROM aggregations
WHERE NOT EXISTS (
SELECT DISTINCT a.element
FROM aggregations a
WHERE a.element NOT IN (2,3,5)
AND a.name = aggregations.name
)
GROUP BY name
HAVING COUNT(element) = 3
It's not very efficient, though.
Create a temporary table, fill it with your values and query like this:
SELECT name
FROM (
SELECT DISTINCT name
FROM aggregations
) n
WHERE NOT EXISTS
(
SELECT 1
FROM (
SELECT element
FROM aggregations aii
WHERE aii.name = n.name
) ai
FULL OUTER JOIN
temptable tt
ON tt.element = ai.element
WHERE ai.element IS NULL OR tt.element IS NULL
)
This is more efficient than using COUNT(*), since it will stop checking a name as soon as it finds the first row that doesn't have a match (either in aggregations or in temptable)
This isn't tested, but usually I would do this with a query in my where clause for a small amount of data. Note that this is not efficient for large record counts.
SELECT ag1.Name FROM aggregations ag1
WHERE ag1.Element IN (2,3)
AND 0 = (select COUNT(ag2.Name)
FROM aggregatsions ag2
WHERE ag1.Name = ag2.Name
AND ag2.Element NOT IN (2,3)
)
GROUP BY ag1.name;
This says "Give me all of the names that have the elements I want, but have no records with elements I don't want"

Grouping by intervals

Given a table (mytable) containing a numeric field (mynum), how would one go about writing an SQL query which summarizes the table's data based on ranges of values in that field rather than each distinct value?
For the sake of a more concrete example, let's make it intervals of 3 and just "summarize" with a count(*), such that the results tell the number of rows where mynum is 0-2.99, the number of rows where it's 3-5.99, where it's 6-8.99, etc.
The idea is to compute some function of the field that has constant value within each group you want:
select count(*), round(mynum/3.0) foo from mytable group by foo;
I do not know if this is applicable to mySql, anyway in SQL Server I think you can "simply" use group by in both the select list AND the group by list.
Something like:
select
CASE
WHEN id <= 20 THEN 'lessthan20'
WHEN id > 20 and id <= 30 THEN '20and30' ELSE 'morethan30' END,
count(*)
from Profiles
where 1=1
group by
CASE
WHEN id <= 20 THEN 'lessthan20'
WHEN id > 20 and id <= 30 THEN '20and30' ELSE 'morethan30' END
returns something like
column1 column2
---------- ----------
20and30 3
lessthan20 3
morethan30 13