When I run both queries individually, they run correctly. But when I try to combine both result sets into one table using the UNION operator, it doesn't run and I get the error message : "Syntax error: Top N option is not allowed in a query connected by set operators."
select
top 1
city,
count(*)
from unicorns
where city is not null and industry = 'Edtech'
group by city
order by 2 desc
union
select
top 1
city,
count(*)
from unicorns
where city is not null and industry = 'Internet software & services'
group by city
order by 2 desc
I would appreciate any help,
Thanks.
Instead you can use window functions to achieve the same:
select
city,
count(*) ccount
from unicorns
where city is not null and industry = 'Edtech'
group by city
QUALIFY ROW_NUMBER() OVER (ORDER BY ccount DESC) = 1
union
select
city,
count(*) ccount
from unicorns
where city is not null and industry = 'Internet software & services'
group by city
QUALIFY ROW_NUMBER() OVER (ORDER BY ccount DESC) = 1
This way you aren't relying on ordering/top an interim result set (outside of partition ordering) and Teradata will be ok with it.
It's probably because the optimizer doesn't know if the 2nd ORDER BY is part of the top or the final ORDER BY of the UNION.
The common workaround for this type of error is to wrap the Selects in Derived Tables/CTEs:
select *
from
(
select
top 1
city,
count(*)
from unicorns
where city is not null and industry = 'Edtech'
group by city
order by 2 desc
) as dt
union
select *
from
(
select
top 1
city,
count(*)
from unicorns
where city is not null and industry = 'Internet software & services'
group by city
order by 2 desc
) as dt
Related
I have a database with 58 customers(58 rows) with a column(country). How do I group up all the rows where a country only appears once and change its name to "Other" using a CASE Statement
SELECT
CASE
WHEN (SELECT COUNT(country) FROM customer GROUP BY country)=1 THEN 'Other'
ELSE country
END country
FROM customer
The problem is that when I run my query, all the countries become Other. I only want the countries that appear once to be called Other.
Here's how to do it.
SELECT
CASE WHEN COUNT(country) = 1 THEN 'Other' ELSE country END
FROM customer
GROUP BY country;
To update the actual table:
WITH map AS
(SELECT country,
CASE WHEN COUNT(country) = 1 THEN 'Other'
ELSE country END mapped
FROM customer
GROUP BY country)
UPDATE customer
SET country = (SELECT mapped FROM map WHERE map.country = customer.country);
With a subquery that counts how many times a country appears in the table:
SELECT
CASE
WHEN (SELECT COUNT(*) FROM customer WHERE country = c.country) = 1 THEN 'Other'
ELSE c.country
END country
FROM customer c
Or with a join of the table to the subquery that returns all the counter of all the countries:
SELECT
CASE
WHEN g.counter = 1 THEN 'Other'
ELSE c.country
END country
FROM customer c INNER JOIN (
SELECT country, COUNT(*) counter
FROM customer
GROUP BY country
) g ON g.country = c.country
If you want your table grouped by the result of this CASE statement use an alias to distinguish from the table's column country:
SELECT
CASE
WHEN (SELECT COUNT(*) FROM customer WHERE country = c.country) = 1 THEN 'Other'
ELSE c.country
END _country
FROM customer c
GROUP BY _country
Case statement with select statement as loops in where condition
need to bring values by referring two tables. if the value doesn't exist in table a it has to refer the 2nd table
Sel * from Table A
where city = (case when (sel distinct city from Table A) is null
then (sel city from Table B) end)
expected output is as shown below
Sel * from Table A
where City = 'XYZ'
if value is not present in table A it has to refer Table B statement and show the value in where condition
The one thing you need to be careful with here is to make sure you return a single value in your scalar sub-queries -- (sel distinct city from Table A) and (sel city from Table B). If you can always guarantee that then I think your query will work as is.
A safer way to do it is guarantee you always get one row. Here's one option:
SELECT *
FROM TableA
WHERE City = (
SELECT city
FROM (
-- Get all cities from TableA
SELECT city, 1 AS table_priority
FROM tableA
UNION ALL
-- Get all cities from TableB
SELECT city, 2
FROM tableB
) src
QUALIFY ROW_NUMBER() OVER(ORDER BY src.table_priority, src.city) = 1 -- Return one row
)
I have two subqueries. as shown below. the first query works fine but the second query which is basically the first query that I modified to use AND & OR, doesn't work in the sense that it doesn't return ID as expected. any suggestions on what is happening here?
1. (SELECT * FROM (SELECT EMPID FROM EVENT_F
INNER JOIN WCINFORMATION_D
ON EVENT_F.JOB_INFO_ROW_WID= WCINFORMATION_D.ROW_WID
INNER JOIN WCANDIDATE_D ON WCCANDIDATE_D.ROW_WID = VENT_F.CANDIDATE_ROW_WID
WHERE STEP_NAME = 'Offer'
AND WCINFORMATION_D.JOB_FAMILY_NAME IN ('MDP','ELP','Emerging Leader Program','Other')
AND TITLE NOT IN ('Student Ambassador Program for Eligible Summer Interns','Student Ambassador')
AND PI_CANDIDATE_NUM = OUTERAPP.PI_CANDIDATE_NUM
--limit 1
ORDER BY CREATION_DT ASC
) T1 WHERE ROWNUM=1) AS A_ID,
2.(SELECT * FROM (SELECT EMPID FROM EVENT_F
INNER JOIN WCINFORMATION_D
ON EVENT_F.JOB_INFO_ROW_WID= WCINFORMATION_D.ROW_WID
INNER JOIN WCANDIDATE_D ON WCCANDIDATE_D.ROW_WID = VENT_F.CANDIDATE_ROW_WID
WHERE STEP_NAME = 'Offer'
AND WCINFORMATION_D.JOB_FAMILY_NAME IN ('MDP','ELP','Emerging Leader Program','Other') or WCINFORMATION_D.JOB_FAMILY_NAME NOT IN ('MDP','ELP','Emerging Leader Program','Other')
AND TITLE NOT IN ('Student Ambassador Program for Eligible Summer Interns','Student Ambassador')
AND PI_CANDIDATE_NUM = OUTERAPP.PI_CANDIDATE_NUM
--limit 1
ORDER BY CREATION_DT ASC
) T1 WHERE ROWNUM=1) AS A_ID,
If you're wanting to get the count of people in one set of job families, plus a count of people in another set, you need to use a conditional count, e.g. something along the lines of:
SELECT COUNT(CASE WHEN wid.job_family_name IN ('MDP', 'ELP', 'Emerging Leader Program', 'Other') THEN 1 END) job_family_grp1,
COUNT(CASE WHEN wid.job_family_name IS NULL OR wid.job_family_name NOT IN ('MDP', 'ELP', 'Emerging Leader Program', 'Other') THEN 1 END) job_family_grp2
FROM event_f ef
INNER JOIN wcinformation_d wid
ON ef.job_info_row_wid = wid.row_wid
INNER JOIN wcandidate_d wcd
ON wcd.row_wid = ef.candidate_row_wid
WHERE step_name = 'Offer' -- alias this column name
AND title NOT IN ('Student Ambassador Program for Eligible Summer Interns', 'Student Ambassador') -- alias this column name;
You will most likely need to amend this to work for your particular case (it'll have to go as a join into your main query, given there are two columns being selected) since you didn't provide enough information in your question to give us the wider context.
select company,
case when ((select count() from ftmuser where active='0' group by company)>5) Then (select count() from ftmuser where active='0' group by company)
ELSE '0'
END
From ftmuser
I want to display only those records having count > 5 but above query fails and says ERROR: more than one row returned by a subquery used as an expression
SQL state: 21000
Please guide me on this.
Thanks.
Try this:
select company, case when ((select count(*) from ftmuser where active='0'
group by company where company=ft.company)>5)
Then (select count() from ftmuser <br>where active='0'
group by company where company=ft.company )
ELSE '0' END
From ftmuser ft
I am trying to assign 'A' to [Student Details].group based on this SELECT statement.
SELECT TOP (10) PERCENT [Person Id], [Given Names], Surname, Gpa, [Location Cd]
FROM [Student Details]
WHERE ([Location Cd] = 'PAR')
ORDER BY Gpa DESC
I can't figure out how to use a SELECT statement in an UPDATE statement.
Can someone please explain how to accomplish this?
I am using ASP .NET and MsSQL Server if it makes a difference.
Thanks
I'm assuming you want to update these records and then return them :
SELECT TOP (10) PERCENT [Person Id], [Given Names], Surname, Gpa, [Location Cd]
INTO #temp
FROM [Student Details]
WHERE ([Location Cd] = 'PAR')
ORDER BY Gpa DESC
update [Student Details] set group='A' where [person id] in(select [person id] from #temp)
select * from #temp
I'm also assuming person id is the PK of student details
Try this using CTE (Common Table Expression):
;WITH CTE AS
(
SELECT TOP 10 PERCENT [Group]
FROM [Student Details]
WHERE ([Location Cd] = 'PAR')
ORDER BY Gpa DESC
)
UPDATE CTE SET [Group] = 'A'
Is this you want?
Update top (10) Percent [Student Details] set [group] = 'A'
where [Location Cd] = 'PAR' AND [group] is null