I have three columns:
Course event
Name, supervisor, place
AAAA martha 3
BBBB josh 2
AAAA evelyn 1
AAAA martha 4
AAAA josh 5
Course
code, price
Place
id, name
I want to find courseevents that has been held at atleast 4 different places. Not including duplicates.
You can use count(distinct place) to count the # of unique places per event and only select those that have at least 4:
select name
from course_event ce
group by name
having count(distinct place) >= 4
Update:
select
user_id
, count(*) as count_distinct_places
from
( select distinct
name,
place
from course_events
) t
group by name
having count(*) >= 4
Related
Consider this table:
id name department email
1 Alex IT blah#gmail.com
1 Alex IT blah#gmail.com
2 Jay HR jay#gmail.com
2 Jay Marketing zou#gmail.com
If I group byid,name and count I get:
id name count(*)
1 Alex 2
2 Jay 2
With this query:
select id,name,count(*) from tb group by id,name;
However I would like to count only records that diverge from department,email, so as to have:
id name count(*)
1 Alex 0
2 Jay 1
This time the count for the first group 1,Alex is 0 because department,email have the same values (duplicated) , on the other hand 2,Jay is one because department,email has one different value.
If you meant "two different values" for "Jay", you can use distinct:
select id,name,count(*) from (SELECT distinct * FROM tb) group by id,name;
You can use count(*) - 1 to get similar results in your question.
Currently I have a table this :
Roll no. Names
------------------
1 Sam
1 Sam
2 Sasha
2 Sasha
3 Joe
4 Jack
5 Jack
5 Julie
I want to write a query in which I get count of the combination in another column
Required output
Combination distinct count
-----------------------------
2-Sasha 1
5-Jack 1
5-Julie 1
Basically, you could group by these columns and use a count function:
SELECT rollno, name, COUNT(*)
FROM mytable
GROUP BY rollno, name
You could also concat the two columns:
SELECT CONCAT(rollno, '-', name), COUNT(*)
FROM mytable
GROUP BY CONCAT(rollno, '-', name)
I am hoping someone can help me with my query.
I have a table with the columns, 'Date', 'ID_Num and 'Name'. What I want to do is add a column at the end to show the total amount of times each ID_Num is within the data but based on the date. So although 'ID_Num' 1001 shows 4 times in total, it is twice on the 20/04/2018 and once on both the 21/04/2018 and 22/04/2018.
EDIT: I should have stipulated that I will be pulling several other columns with information, which I cant use a group by on everything.
Date ID_Num Name Count
20/04/2018 1001 John 2
20/04/2018 1001 John 2
20/04/2018 1002 Paul 2
20/04/2018 1002 Paul 2
20/04/2018 1003 David 2
20/04/2018 1003 David 2
20/04/2018 1004 Stephen 1
21/04/2018 1001 John 1
21/04/2018 1002 Paul 3
21/04/2018 1002 Paul 3
21/04/2018 1002 Paul 3
21/04/2018 1004 Stephen 1
22/04/2018 1001 John 1
22/04/2018 1002 Paul 1
22/04/2018 1003 David 1
22/04/2018 1004 Stephen 1
Thanks
Unless I'm missing something here, a simple group by and count should do it:
SELECT Date, ID_Num, Name, Count(*)
FROM TableName
GROUP BY Date, ID_Num, Name
(That is, assuming there can only be one Name for each ID_Num)
Update
Assuming your rdbms supports it, you can use count with an over clause:
SELECT Date, ID_Num, Name, Count(*) OVER(PARTITION BY Date, Id_Num)
FROM TableName
If not, you can use a sub query:
SELECT Date,
ID_Num,
Name,
(SELECT Count(*)
FROM TableName As t1
WHERE t1.Date = t0.Date
AND t1.ID_NUM = t0.ID_NUM)
FROM TableName As t0
Try this:
SELECT
Date,
Id_num,
count(*) count
FROM
tabel_name
GROUP BY
Date,
Id_num
If you want name as well:
SELECT
Date,
Id_num,
Name
count(*) count
FROM
tabel_name
GROUP BY
Date,
Id_num,
Name
You can use a normal select query and then add a sub query to do a group and show the total. Simple example below
SELECT Date, ID_Num, Name,
(SELECT Count(ID_Num) FROM TableName AS CHILD WHERE CHILD.Id_Num = Parent.Id_Num) AS Total
FROM TableName AS Parent
How can I find if a name is assigned different client number?
For example, how can I find Jude in the dataset was assigned three different client numbers? I've tried to use group by to find the duplicate client numbers.
ID CLIENT_NUMBER NAME START_DT END_DT
1 1 Jude 2017-09-13 NULL
2 2 Jude 2017-09-19 2017-09-26
3 3 Jude 2017-09-26 null
You could count how many distinct client_numbers each name has:
SELECT name
FROM mytable
GROUP BY name
HAVING COUNT(DISTINCT client_name) > 1
Try:
SELECT NAME
FROM
YOUR_TABLE
GROUP BY NAME
HAVING COUNT(DISTINCT CLIENT_NUMBER) > 1;
I got the following records where different people have the same name:
id name category_id birthdate family_id
1 joe 2 2014-05-01 1
2 jack 3 2013-04-01 2
3 joe 2 1964-05-01 1
4 jack 5 1982-05-01 2
5 emma 1 2014-05-01 1
6 joe 3 2003-07-06 3
Now I need a query which results to the following. I want only each name once per family_id. I need all values of each record afterwards including the id. In case the table gets further rows down the road I need them too. So the result should include all values.
id name category_id birthdate family_id
1 joe 2 2014-05-01 1
2 jack 3 2013-04-01 2
5 emma 1 2014-05-01 1
6 joe 3 2003-07-06 3
I tried it with several approaches (GROUP BY, DISTINCT, DISTINCT ON etc.) but none was working out for me.
When I use a GROUP BY clause (GROUP BY name) I get a ERROR: column "deals.id" must appear in the GROUP BY clause or be used in an aggregate function. But when I put id inside the clause I get all records back.
Same with distinct. There I have to choose all fields on which the result set should be distinct. But I need all values of the record. And because of the primary each record is distinct when i include the id.
I tried it with a sub clause which has filtered all distinct names. I used them in a where clause. But I got all values back including (of course) the not distinct name/family_id records.
Has anybody a helping hand for me?
You might not of specified all of the fields in your group by and if you included id, then that would make the rows unique.
Try something like:
SELECT
name, category_id, birthdate, family_id
FROM family
GROUP BY
name, category_id, birthdate, family_id;
It worked with DISTINCT ON.
The following worked quite well:
SELECT DISTINCT ON (table.name, table.family_id) table.* FROM table;
The only thing I have to check is the ordering. But I wanted to share my solution so far.