I have the following table structured like this:
So basically as you can see, the department goes through name changes every couple of years. Look at number 16 for example. I want a select query that will only get the name when the date is the greatest. How do I do that?
select ID, Name from departments o
where o.thedate=
(select max(i.thedate) from departments i where o.id=i.id)
SELECT ID,
First(Name) AS FirstOfName, First(DateChange) AS FirstOfDateChange
FROM departments
GROUP BY ID
ORDER BY First(DateChange) DESC;
What is the primary key for this table? This does a subquery the same table with a name comparison.
SELECT
id,
name,
date
FROM table
WHERE name = (SELECT TOP 1 name
FROM table AS subtable
WHERE subtable.name = table.name
ORDER BY date DESC)
SELECT d.*
FROM Departments d
INNER JOIN (SELECT pk
FROM Departments
GROUP BY ID
HAVING theDate=MAX(theDate)) m ON m.pk=d.pk
WHERE [Name]="Department"
Related
I have this table called item:
| PERSON_id | ITEM_id |
|------------------|----------------|
|------CP2---------|-----A03--------|
|------CP2---------|-----A02--------|
|------HB3---------|-----A02--------|
|------BW4---------|-----A01--------|
I need an SQL statement that would output the person with the most Items. Not really sure where to start either.
I advice you to use inner query for this purpose. the inner query is going to include group by and order by statement. and outer query will select the first statement which has the most items.
SELECT * FROM
(
SELECT PERSON_ID, COUNT(*) FROM TABLE1
GROUP BY PERSON_ID
ORDER BY 2 DESC
)
WHERE ROWNUM = 1
here is the fiddler link : http://sqlfiddle.com/#!4/4c4228/5
Locating the maximum of an aggregated column requires more than a single calculation, so here you can use a "common table expression" (cte) to hold the result and then re-use that result in a where clause:
with cte as (
select
person_id
, count(item_id) count_items
from mytable
group by
person_id
)
select
*
from cte
where count_items = (select max(count_items) from cte)
Note, if more than one person shares the same maximum count; more than one row will be returned bu this query.
I am looking to query my Access database from Excel (DAO) to determine if any name in the table has more than one record per date. E.g. If Bob has two records on 05/05/17 then I want to return both records as part of a recordset.
Seems like you are looking for something like:
SELECT *
FROM yourtable
INNER JOIN
(
SELECT count(*), name, date
FROM yourtable
GROUP BY name, date
HAVING COUNT(*) > 1
) multi
ON multi.name = yourtable.name
AND multi.date = yourtable.date
The inner select returns rows with more than 1 entry for the same name and date.
In Access you can do
select name, date
from your_table
group by name, date
having count(*) > 1
For instance, I have a table with columns below:
pk_id,address,first_name,last_name
and I have a query like this to display the first name ans last name that are repetitive(duplicates)
select first_name,last_name
from table
group by first_name,last_name
having count(*)>1;
but the above query just returns first and last names but I want to display pk_id and address too that are tied to these duplicate first and last names
Can we use joins to do this on the same table.Please help!!
A simple way of doing is to build a view with the pk_id and the count of duplicates. Once you have it, it is only a matter of using a JOIN on the base table, and a filter to only keep rows having a duplicate:
SELECT T.*
FROM T
JOIN (SELECT "pk_id",
COUNT(*) OVER(PARTITION BY "first_name", "last_name") cnt
FROM T) V
ON T."pk_id" = V."pk_id"
WHERE cnt > 1
See http://sqlfiddle.com/#!4/3ecd0/9
You have to call it from an outer query, like this:
select * from table
where first_name||last_name in
(select first_name||last_name from
(select first_name, last_name, count( * )
from table
group by first_name,last_name
having count( * ) > 1
)
)
note: you may not need to concatenate the 2 fields, but I haven't tested thaT.
with
my_duplicates as
(
select
first_name,
last_name
from
my_table
group by
first_name,
last_name
having
count(*) > 1
)
select
bb.pk_id,
bb.address,
bb.first_name,
bb.last_name
from
my_duplicates aa
join my_table bb on
(
aa.first_name = bb.first_name
and
aa.last_name = bb.last_name
)
order by
bb.last_name,
bb.first_name,
bb.pk_id
Hoe can I do following thing without using a VIEW from one Query.
!--CREATE THE VIEW
CREATE OR REPLACE VIEW BDGTMGR
AS
SELECT MANAGERID,SUM(BUDGET) AS BDGT FROM
N_DEPT GROUP BY MANAGERID ;
!-- THEN GET RESULT FROM THE VIEW
SELECT MANAGERID FROM BDGTMGR WHERE BDGT = (select MAX(BDGT) FROM BDGTMGR);
Here N_DEPT is may original Table which has columns named DID, MANAGERID and BUDGET.
I want to get MANAGERID who controls Maximum Budget. A Manager can control more than one Department. DID is the primary key for this table.
How can I do this?
select MANAGERID,SUM(BDGT)
from N_DEPT
group by MANAGERID
order by SUM(BDGT) desc limit 1
You can do it like this:
SELECT aux.MANAGERID
FROM
(SELECT MANAGERID,
SUM(BUDGET) AS BDGT
FROM N_DEPT
GROUP BY MANAGERID) aux
INNER JOIN BDGTMGR b ON b.MANAGERID = aux.MANAGERID
WHERE b.BDGT = (select MAX(BDGT) FROM BDGTMGR);
The following query will work (modify depending on your flavour of SQL):
SELECT TOP 1 MANAGERID FROM N_DEPT GROUP BY MANAGERID ORDER BY SUM(BUDGET) DESC
i would like your help with my query.I have a table employee.details with the following columns:
branch_name, firstname,lastname, age_float.
I want this query to list all the distinct values of the age_float
attribute, one in each row of the result table, and beside each in the second field show the
number of people in the details table who had ages less than or equal to that value.
Any ideas? Thank you!
You can use OLAP functions:
SELECT DISTINCT age_float,
COUNT(lastname) OVER(ORDER BY age_float) AS number
FROM employee_details
COUNT(lastname) OVER(ORDER BY age_float) AS number orders rows by age, and returns employees count whose age <= current row age
or a simple join:
SELECT A.age_float, count(lastname)
FROM (SELECT DISTINCT age_float FROM employee_details) A
JOIN employee_details AS ED ON ED.age_float <= A.age_float
GROUP BY A.age_float