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
Related
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;
I want to count the number of ABC group using id.
SELECT group, count(id) as total FROM `user` WHERE group=`ABC`;
What's wrong?
Many thanks.
Include the columns in the select list in group by clause when using aggregate functions.
SELECT group, count(id) as total FROM user
WHERE group=`ABC`
GROUP BY group
Else simply get the count with out using other columns in the select statement.
SELECT count(id) as total FROM user
WHERE group=`ABC`
Try this:
SELECT group, count(id) as total FROM `user`
group by group having group like 'ABC';
If you want to get COUNT of users, who has the "group" field = "ABC"
SELECT count(id) as total FROM user WHERE group='ABC';
Also, it's better to avoid using SQL keywords in column names (GROUP is an SQL keyword)
I want to know how many items of distinct name I have in my database.
When I use:
select count(distinct name) from products
I obviously gain only number of different, distinct names I have in my
database. I was experimenting with group by, but as a total beginner I
failed. I'll appreciate any help.
Group by name and use count() to get the counts for each group
select name, count(*)
from products
group by name
select count(name) as ct, name from products group by name
SELECT NAME, COUNT(*) FROM products GROUP BY name
I'm concatenating two fields and I only want to order by the second field (p.organizationname). Is that possible?
I'm displaying this field so I need a solution that doesn't include me having to select the fields separately.
Here is what i have so far:
SELECT distinct Concat(Concat(f.REFERENCEFILE, ','),p.ORGANIZATIONNAME)
FROM PEOPLE p,FOLDER f,FOLDERPEOPLE fp,folderinfo fi...
Order By concat(Concat(f.REFERENCEFILE, ','),p.ORGANIZATIONNAME)
Use GROUP BY and ORDER BY an aggregate instead of DISTINCT:
SELECT Concat(Concat(f.REFERENCEFILE, ','),p.ORGANIZATIONNAME)
FROM PEOPLE p,FOLDER f,FOLDERPEOPLE fp,folderinfo fi...
GROUP BY Concat(Concat(f.REFERENCEFILE, ','),p.ORGANIZATIONNAME)
Order By MAX(p.ORGANIZATIONNAME)
The problem can be illustrated with an example:
ID Col1
1 Dog
1 Cat
2 Horse
Distinct ID? Easy: 1,2
Distinct ID Order by Col1... wait.. which value of Col1 should SQL use? SQL is confused and angry.
Since you are using a concatenation of two fields and want to sort by one of those fields, you could also include the sort field in a DISTINCT subquery and then ORDER BY the sort field without including it in your SELECT list.
Since you have a DISTINCT your ORDER BY clause should be specified in the SELECT, you can use a subquery to achieve the same result in your case since the Distinct values will be the same when you add P.ORGANIZATIONNAME
SELECT col
FROM( SELECT distinct Concat(Concat(f.REFERENCEFILE, ','),p.ORGANIZATIONNAME) a,
p.ORGANIZATIONNAME b
FROM PEOPLE p,FOLDER f,FOLDERPEOPLE fp,folderinfo fi... ) t
order by b
When I try to use the following SELECT statement:
SELECT [lots of columns]
FROM Client, Customer, Document, Group
WHERE [some conditions]
GROUP BY Group.id
SQL Server complains that the columns I selected are not part of the GROUP BY statement nor an aggregate function. Am I using GROUP BY wrong? What should I be using instead?
To return all single occurences of a group by field, together with associated field values, write a query like:
select group_field,
max(other_field1),
max(other_field2),
...
from mytable1
join mytable2 on ...
group by group_field
having count(*) = 1;
Yes, you are using GROUP BY incorrectly. The point of using GROUP BY is to use aggregate functions. If you have no aggregrate functions you probably want SELECT DISTINCT instead.
SELECT DISTINCT
col1,
col2,
-- etc
coln
FROM Client
JOIN Customer ON ...
JOIN Document ON ...
JOIN [Group] ON ...
WHERE ...
My first guess would be that the problem is that you have table called Group, which I believe is a reserved word in SQL. Try wrapping the Group name with ' '
You want to group by all columns you are selecting that is not in an aggregate funcion.
SELECT ProductName, ProductCategory, SUM(ProductAmount)
FROM Products
GROUP BY ProductName, ProductCategory
This will give you a disticnt result of Product names and categories with the sum total of product amount in all aggregate child records for that group.