SQL Inner Join related_Mahavir - sql

I have 3 columns ID,NAME,VALUE as 1,2,3,4,5/A,B,C,A,B/9,9,9,9,9 so I want total SUM for particular name e.g. A-18, B-18, C-9...please answer the query in SQL form.

SELECT name, SUM(value) FROM whatevertable GROUP BY name

I assume you are asking to sum the columns & get an output based on your column Name.
Select Name + '-' + ltrim(rtrim(str( sum(Value) ))) from
tablename group by Name

Related

Filter by number of occurrences in a SQL Table

Given the following table where the Name value might be repeated in multiple rows:
How can we determine how many times a Name value exists in the table and can we filter on names that have a specific number of occurrances.
For instance, how can I filter this table to show only names that appear twice?
You can use group by and having to exhibit names that appear twice in the table:
select name, count(*) cnt
from mytable
group by name
having count(*) = 2
Then if you want the overall count of names that appear twice, you can add another level of aggregation:
select count(*) cnt
from (
select name
from mytable
group by name
having count(*) = 2
) t
It sounds like you're looking for a histogram of the frequency of name counts. Something like this
with counts_cte(name, cnt) as (
select name, count(*)
from mytable
group by name)
select cnt, count(*) num_names
from counts_cte
group by cnt
order by 2 desc;
You need to use a GROUP BY clause to find counts of name repeated as
select name, count(*) AS Repeated
from Your_Table_Name
group by name;
If You want to show only those Which are repeated more than one times. Then use the below query which will show those occurrences which are there more than one times.
select name, count(*) AS Repeated
from Your_Table_Name
group by name having count(*) > 1;

How to group an already grouped data-set in oracle sql

I want to first group data as per "Roll" and then further group it as per "Name" with different "Marks".
I have grouped data using Group by and having but I am not sure how to further group it.
Group by two columns :
SELECT Roll,Name FROM table GROUP BY Roll,Name;
If you want to see marks also you have aggegrate(sum) it like :
SELECT Roll,Name,sum(Marks)as 'Total Marks' FROM table GROUP BY Roll,Name;
If you want to see marks also you have aggegrate(average) it like :
SELECT Roll,Name,avg(Marks)as 'Average Marks' FROM table GROUP BY Roll,Name;
Refer this image
If I understand correctly, you want roll/name pairs that have multiple distinct values. You can do this using window functions:
select distinct roll, name, marks
from (select t.*, count(distinct marks) over (partition by roll, name) as cnt
from t
) t
where cnt > 1;

How to check if a person has duplicate date records?

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

Column is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause

I'm trying to select the latest date and group by name and keep other columns.
For example:
name status date
-----------------------
a l 13/19/04
a n 13/09/05
a dd 13/18/03
b l 13/01/01
b dd 13/01/02
b n 13/01/03
and I want the result like:
name status date
-----------------
a n 13/09/05
b n 13/01/03
Here's my code
SELECT
Name,
MAX(DATE) as Date,
Status
FROM
[ST].[dbo].[PS_RC_STATUS_TBL]
GROUP BY
Name
I know that I should put max(status) because There are a lot of possibilities in each case, and nothing in the query makes it clear which value to choose for status in each group. Is there anyway to use inner join ?
It's not clear to me you want the max or min status. Rather it seems to me you want the name and status as of a date certain. That is, you want the rows with the lastest date for each name. So ask for that:
select * from PS_RC_STATUS_TBL as T
where exists (
select 1 from PS_RC_STATUS_TBL
where name = T.name
group by name
having max(date) = T.date
)
Another way to think about it is
select T.*
from PS_RC_STATUS_TBL as T
join (
select name, max(date) as date
from PS_RC_STATUS_TBL
group by name
) as D
on T.name = D.name
and T.date = D.date
SQL Server needs to know what to do with the rows that you are not grouping on (it has multiple rows to show on 1 line - so how?). If you have aggregated on them (MIN, MAX, AVG, etc) then you are telling it what to do with these rows. If not it will not know what to do - and will give you an error like the one you are getting.
From what you are saying though - it sounds like you do not want to group by the status. It sounds like you are not interested in that column at all. Let me know If that assumption is wrong.
SELECT
Name,
MAX(Date) AS 'Date',
FROM
PS_RC_STATUS_TBL
GROUP BY
Name
If you really do want the status, but don't want to group on it - try this:
SELECT
MyTable1.Name,
MyTable2.Status,
MyTable1.Date
FROM
(SELECT Name, MAX(Date) AS 'Date' FROM PS_RC_STATUS_TBL GROUP BY Name) MyTable1
INNER JOIN
(SELECT Name, Date, Status FROM PS_RC_STATUS_TBL) MyTable2
ON MyTable1.Name = MyTable2.Name
AND MyTable1.Date = MyTable2.Date
That gives the exact results you've asked for - so does the method below using a CTE.
OR
WITH cte AS (
SELECT Name, MAX(Date) AS Date
FROM PS_RC_STATUS_TBL
GROUP BY Name)
SELECT cte.Name,
tbl.Status,
cte.Date
FROM cte INNER JOIN
PS_RC_STATUS_TBL tbl ON cte.Name = tbl.Name
AND cte.Date = tbl.Date
SQLFiddle example.
It just means that you need to put all non-aggregated columns in the GROUP BY clause, so in the case you need to put the other one
Select Name ,
MAX(DATE) as Date ,
Status
FROM [ST].[dbo].[PS_RC_STATUS_TBL] PS
Group by Name, Status
This is a common problem with text fields in SQL aggregation scenarios. Using either MAX(Status) or MIN(Status) in your field list is a solution, usually MAX(Status) because of the lexical ordering:
"" < " " < "a"
In cases where you really need a more detailed ordering:
Join to a StatusOrder relation (*Status, OrderSequence) in your main query;
select Max(OrderSequence) in your aggregated query; and
Join back to your StatusOrder relation on OrderSequence to select the correct Status value for display.
Whatever fields you're selecting other than aggregation function, need to mention in group by clause.
SELECT
gf.app_id,
ma.name as name,
count(ma.name) as count
FROM [dbo].[geo_fen_notification_table] as gf
inner join dbo.mobile_applications as ma on gf.app_id = ma.id
GROUP BY app_id,name
Here im accessing app_id and name in select, so i need to mention that after group by clause. otherwise it will throw error.

SQL To get Distinct Name and Number from table

Looking for sql to get distinct names and count of those names from a sql table:
Structure:
id
name
other details
Do I use distinct to get each group and then count through those to get:
name1 count(name1)
name2 count(name2)
etc
Thanks
Rob.
When you want a COUNT() or a SUM(), you're using an AGGREGATE FUNCTION based on a GROUP BY clause.
As GROUP BY brings together all records with the same values specified in the GROUP BY columns, you're already getting the same effect as DISTINCT.
Except that DISTINCT doesn't allow aggregates, and GROUP BY does.
SELECT
name,
COUNT(*) AS count_of_name
FROM
yourTable
GROUP BY
name
Try :
SELECT *, COUNT(*) FROM my_table GROUP BY name
Something like this?
select name,COUNT(name) FROM Persons GROUP BY name
In the end I used:
SELECT DISTINCT `school`,COUNT(`school`) AS cat_num FROM table GROUP BY school order by cat_num DESC