I've got 2 columns filled with names. The list is seemingly random and a person's name could show up in column A or column B (but never in both at the same instance). I want to write a query that will tell me all the names and the number of times each person is in either list. Here's an example of what I'm talking about
Col A
Col B
Mark
Cheryl
Andy
Tom
James
Mark
Tom
Ann
Cheryl
Jeff
Andy
Mark
I'm looking for a query/function that will give me the list of names and the number of times they were seen in either column.
Any help is always appreciated!
Assuming your table name is names and your columns are a,b then this should work:
select n.name, count(n.name)
from (
select a as name from names
union all
select b as name from names
) n
group by n.name;
SELECT
Name,
COUNT(1) as cnt
FROM (
SELECT ColA As Name FROM my_table UNION ALL
SELECT ColB As Name FROM my_table
) t
GROUP BY
Name
db fiddle
Related
I want to select from a table where a name appears twice.
For example I have a table like this,
ID Name
---- ------
1 Jane John
2 Kevin Smith
3 Jane John
What I want is for the output to show where Jane John appear twice so it should look something like this:
ID Name
---- ------
1 Jane John
3 Jane John
I tried looking around on stackoverflow but couldn't find an exact and easy answer.
I'm using oracle SQL Developer.
You ask for a record that appears twice. If a row appears three times it won't show unless you modify the having clause as commented.
SELECT id
,NAME
FROM tablen
WHERE NAME IN (
SELECT NAME
FROM TableN n
GROUP BY (NAME)
HAVING counT(NAME) = 2 --Use >1 instead of =2 for more than one record
)
EDIT
I'll add a new solution in regard to your last comment.
As you can only ask for one field in IN() I'll use a special character or string making sure it does not belongs to valid values in any field.
Look at this: http://sqlfiddle.com/#!6/2af55/3
SELECT id
,NAME
,name2
FROM tablen
WHERE concat(NAME,'=',name2) IN (
SELECT concat(NAME,'=',name2)
FROM TableN n
GROUP BY concat(NAME,'=',name2)
HAVING count(concat(NAME,'=',name2)) = 2
)
Note I wrote this thinking in SQL Server, not sure if concat function works as well in Oracle or look for an alternative.
I have an SQL Server 2012 table with ID, First Name and Last name. The ID is unique per person but due to an error in the historical feed, different people were assigned the same id.
------------------------------
ID FirstName LastName
------------------------------
1 ABC M
1 ABC M
1 ABC M
1 ABC N
2 BCD S
3 CDE T
4 DEF T
4 DEG T
In this case, the people with ID’s 1 are different (their last name is clearly different) but they have the same ID. How do I query and get the result? The table in this case has millions of rows. If it was a smaller table, I would probably have queried all ID’s with a count > 1 and filtered them in an excel.
What I am trying to do is, get a list of all such ID's which have been assigned to two different users.
Any ideas or help would be very appreciated.
Edit: I dont think I framed the question very well.
There are two ID's which are present multiple time. 1 and 4. The rows with id 4 are identical. I dont want this in my result. The rows with ID 1, although the first name is same, the last name is different for 1 row. I want only those ID's whose ID is same but one of the first or last names is different.
I tried loading ID's which have multiple occurrences into a temp table and tried to compare it against the parent table albeit unsuccessfully. Any other ideas that I can try and implement?
SELECT
ID
FROM
<<Table>>
GROUP BY
ID
HAVING
COUNT(*) > 1;
SELECT *
FROM myTable
WHERE ID IN (
SELECT ID
FROM myTable
GROUP BY ID
HAVING MAX(LastName) <> MIN(LastName) OR MAX(FirstName) <> MIN(FirstName)
)
ORDER BY ID, LASTNAME
this question was probably asked somewhere but I can't seem to phrase it correctly in the search to find an accurate answer.
I'm doing a query on a Postgres DB, it has quite a few joins, the results are something like this:
WON | name | item
1 Joe A
1 Joe B
2 Smith A
So one row for each entry, I need to somehow get the result back as such:
WON | name | item
1 Joe A, B
2 Smith A
This can be done in the query or with NodeJS, there are hundreds to thousands of results for the query, so getting a distinct row (WON 1) then searching the DB for all entries that match it then repeating for the rest isn't feasible, so this may be better done in Node / Javascript, but I'm somewhat new to that, what would be a (somewhat) efficient way to do this?
If there IS a way to do this in the query itself then that would be my preference though.
Thanks
A sql approach:
SELECT won, name
,STRING_AGG(item, ',' ORDER BY item) AS items
FROM myTable
GROUP BY won, name
ORDER BY won, name
You can use GROUP BY and string_agg to cancat rows, somelike this:
Create table:
CREATE TABLE test
(
won int,
name character varying(255),
item character varying(255)
);
insert into test (won, name, item) values (1,'Joe', 'A'),(1, 'Joe', 'B'),(2, 'Smith', 'A')
And do this in the query:
select won, name, string_agg(item, ',') from test group by won, name order by won
See this example in sqlFiddle
I have this situation in a certain table:
id | name
1 'Test'
2 'Test'
3 'Test'
How can I make a query to SELECT by distinct the name? I also need the ID column, even if I get the first occurrence of the element, e.g. "if the name column repeats, give me the first record with this repetition."
select name, MIN(ID)
from aCertainTable
group by name
Let's say I have a table with 2 columns number and name.
number name
--------------
0 name1
3 name4
3 name2
5 name1
So the number column has repeats in it and one or more (distinct) names assigned to each number. But for example, number 3 could have the same name as number 5.
How do I show all the distinct names for each number using group by in such a way that I get as a result both number and name.
I am trying to do this but I can't figure it due to must having the columns in SELECT in GROUP BY also.
Is this what you want?
SELECT NUMBER, NAME
FROM TABLENAME
GROUP BY NUMBER, NAME
ORDER BY NUMBER
First Thing 'Number' is a reserved word in sql so don't use it as a column name
Suppose your 'Number' column name is 'Number1"
then try this
select name, number1 from tableName
GROUP BY name, number1