I have a table with data
ID Name
1 John
2 Robert
3 John
4 Sam
5 Jack
6 Sam
Now i want ony the the duplicate names ony through query
ie..,
Name
John
Sam
SELECT Name
FROM YourTable
GROUP BY Name
HAVING COUNT(*) > 1
CREATE TABLE MyTable (
ID int
, Name nvarchar(50)
)
INSERT MyTable VALUES ( 1, 'John' )
INSERT MyTable VALUES ( 2, 'Robert' )
INSERT MyTable VALUES ( 3, 'John' )
INSERT MyTable VALUES ( 4, 'Sam' )
INSERT MyTable VALUES ( 5, 'Jack' )
INSERT MyTable VALUES ( 6, 'Sam' )
SELECT
Name
FROM
MyTable
GROUP BY
Name
HAVING
COUNT(*) > 1
DROP TABLE MyTable
Results:
Name
--------------------------------------------------
John
Sam
with temp as (
select Name, count(Name) as countOfNames
from myTable
group by Name
)
select Name from temp
where countOfNames > 1
select columnname,count(column name) from tablename group by column name having count(*)>1
Related
This question already has answers here:
Is there a way to access the "previous row" value in a SELECT statement?
(9 answers)
Closed 4 months ago.
Lets say I have a table like this;
Id
Name
1
John
2
Doe
5
Rose
11
Michael
15
Pedro
and my select query like this;
Id
Name
1
John
5
Rose
I want to select next rows according to my query which like this;
Id
Name
2
Doe
11
Michael
1 Johns next row is 2 Doe and 5 Roes's next row 11 Michael
One of many ways to do this:
WITH
RowNumbers AS (
SELECT
*,
ROW_NUMBER() OVER (ORDER BY ID) AS RowNumber
FROM
TableName -- replace with your table name
)
SELECT
Id,
Name
FROM
RowNumbers
WHERE
RowNumber IN (
SELECT
RowNumber+1
FROM
RowNumbers
WHERE
Name IN ('John', 'Rose')
)
;
You could use a CTE to create row_numbers and then select and join to it.
create table my_data (
id integer,
name varchar(20)
);
insert into my_data (id, name) values
(1, 'john'),
(2, 'doe'),
(5, 'rose'),
(11, 'michael'),
(15, 'pedro');
with row_data as (
select id, name,
row_number() over (order by id) as rn
from my_data
)
select b.id, b.name
from row_data a
join row_data b
on a.rn + 1 = b.rn
where a.name in ('john','rose')
id
name
2
doe
11
michael
fiddle
I have the following simple table (Table1), where each row is a student_ID and their name, and each student has one or multiple wins (Wins). I would like to output: Student_ID, Student_name, count of Wins, sorted by count of Wins (descending) and then Student_ID (ascending), excluding those students who have the same count of Wins which is less than the max of the Wins (i.e.5). In other words, Lizzy and Mark have the same count of wins, and 3 is lower than 5, so the output will exclude the two students, Lizzy and Mark.
From comments: "Betty, David and Cathy should be excluded", also.
Table1:
student_id
student_name
wins
1
John
YES
1
John
YES
1
John
YES
1
John
YES
1
John
YES
2
Brandon
YES
2
Brandon
YES
2
Brandon
YES
2
Brandon
YES
2
Brandon
YES
3
Lizzy
YES
3
Lizzy
YES
3
Lizzy
YES
4
Mark
YES
4
Mark
YES
4
Mark
YES
5
Betty
YES
6
David
YES
7
Cathy
YES
8
Joe
YES
8
Joe
YES
Desired output:
student_id
student_name
cnt_wins
1
John
5
2
Brandon
5
8
Joe
2
Here is my SQL in Oracle. I can't figure out what went wrong. The log says "(SELECT b.cnt_wins, count(b.student_id) has too many values".
WITH st_cte AS
(SELECT student_id, student_name, count(wins) cnt_wins
FROM Table1
GROUP BY student_id, student_name
ORDER BY count(wins) DESC, student_id)
SELECT *
FROM st_cte a
WHERE a.cnt_wins not in
(SELECT b.cnt_wins, count(b.student_id)
FROM st_cte b
WHERE b.cnt_wins <
(SELECT max(c.cnt_wins) FROM st_cte c)
GROUP BY b.cnt_wins
HAVING count(b.student_id) > 1);
There are too many values selected inside the 'in' select:
WHERE a.cnt_wins -- 1 value
not in
(SELECT b.cnt_wins, count(b.student_id) -- 2 values
FROM st_cte b
you shoud either do :
WHERE a.cnt_wins not in
(SELECT b.cnt_wins
FROM st_cte ...
or
WHERE (a.cnt_wins, count(something)) not in
(SELECT b.cnt_wins, count(b.student_id)
FROM st_cte ...
Updated based on updated requirements...
The requirement was ambiguous in that Betty, David, and Cathy seem to also meet the criteria to be removed from the result. This requirement was clarified and those rows should have been removed.
Logic has been added to allow only all max_cnt rows, plus any students with a unique count.
Also note that if wins can be any other non-null value, COUNT(wins) is not correct.
Given all that, maybe something like this is a starting point:
Fiddle
WITH cte AS (
SELECT student_id, student_name
, COUNT(wins) cnt_wins
, MAX(COUNT(wins)) OVER () AS max_cnt
FROM Table1
GROUP BY student_id, student_name
)
, cte2 AS (
SELECT cte.*
, COUNT(*) OVER (PARTITION BY cnt_wins) AS cnt_students
FROM cte
)
SELECT student_id, student_name, cnt_wins
FROM cte2
WHERE max_cnt = cnt_wins
OR cnt_students = 1
ORDER BY cnt_wins DESC, student_id
;
and to handle wins that can be other non-null values:
WITH cte AS (
SELECT student_id, student_name
, COUNT(CASE WHEN wins = 'YES' THEN 1 END) cnt_wins
, MAX(COUNT(CASE WHEN wins = 'YES' THEN 1 END)) OVER () AS max_cnt
FROM Table1
GROUP BY student_id, student_name
)
, cte2 AS (
SELECT cte.*
, COUNT(*) OVER (PARTITION BY cnt_wins) AS cnt_students
FROM cte
)
SELECT student_id, student_name, cnt_wins
FROM cte2
WHERE max_cnt = cnt_wins
OR cnt_students = 1
ORDER BY cnt_wins DESC, student_id
;
Result (with data to test the new requirement, one student (Joe) with unique counts (2)):
STUDENT_ID
STUDENT_NAME
CNT_WINS
1
John
5
2
Brandon
5
8
Joe
2
Setup:
CREATE TABLE table1 (
Student_ID int
, Student_Name VARCHAR2(20)
, Wins VARCHAR2(10)
);
BEGIN
-- Assume only wins are stored.
INSERT INTO table1 VALUES ( 1, 'John', 'YES');
INSERT INTO table1 VALUES ( 1, 'John', 'YES');
INSERT INTO table1 VALUES ( 1, 'John', 'YES');
INSERT INTO table1 VALUES ( 1, 'John', 'YES');
INSERT INTO table1 VALUES ( 1, 'John', 'YES');
INSERT INTO table1 VALUES ( 2, 'Brandon', 'YES');
INSERT INTO table1 VALUES ( 2, 'Brandon', 'YES');
INSERT INTO table1 VALUES ( 2, 'Brandon', 'YES');
INSERT INTO table1 VALUES ( 2, 'Brandon', 'YES');
INSERT INTO table1 VALUES ( 2, 'Brandon', 'YES');
INSERT INTO table1 VALUES ( 3, 'Lizzy', 'YES');
INSERT INTO table1 VALUES ( 3, 'Lizzy', 'YES');
INSERT INTO table1 VALUES ( 3, 'Lizzy', 'YES');
INSERT INTO table1 VALUES ( 4, 'Mark', 'YES');
INSERT INTO table1 VALUES ( 4, 'Mark', 'YES');
INSERT INTO table1 VALUES ( 4, 'Mark', 'YES');
INSERT INTO table1 VALUES ( 5, 'Betty', 'YES');
INSERT INTO table1 VALUES ( 6, 'David', 'YES');
INSERT INTO table1 VALUES ( 7, 'Cathy', 'YES');
INSERT INTO table1 VALUES ( 8, 'Joe', 'YES');
INSERT INTO table1 VALUES ( 8, 'Joe', 'YES');
END;
/
Correction to the original query in the question:
WITH st_cte AS
(SELECT student_id, student_name, count(wins) cnt_wins
FROM Table1
GROUP BY student_id, student_name
ORDER BY count(wins) DESC, student_id
)
SELECT *
FROM st_cte a
WHERE a.cnt_wins not in
(SELECT b.cnt_wins
FROM st_cte b
WHERE b.cnt_wins < (SELECT max(c.cnt_wins) FROM st_cte c)
GROUP BY b.cnt_wins
HAVING count(b.student_id) > 1
)
;
I have a table with the columns below, and I need to get the values if COD is duplicated, get the non NULL on VALUE column. If is not duplicated, it can get a NULL VALUE. Like the example:
I'm using SQL SERVER.
This is what I get:
COD ID VALUE
28 1 NULL
28 2 Supermarket
29 1 NULL
29 2 School
29 3 NULL
30 1 NULL
This is what I want:
COD ID VALUE
28 2 Supermarket
29 2 School
30 1 NULL
What I'm tryin' to do:
;with A as (
(select DISTINCT COD,ID,VALUE from CodId where ID = 2)
UNION
(select DISTINCT COD,ID,NULL from CodId where ID != 2)
)select * from A order by COD
You can try this.
DECLARE #T TABLE (COD INT, ID INT, VALUE VARCHAR(20))
INSERT INTO #T
VALUES(28, 1, NULL),
(28, 2 ,'Supermarket'),
(29, 1 ,NULL),
(29, 2 ,'School'),
(29, 3 ,NULL),
(30, 1 ,NULL)
;WITH CTE AS (
SELECT *, RN= ROW_NUMBER() OVER (PARTITION BY COD ORDER BY VALUE DESC) FROM #T
)
SELECT COD, ID ,VALUE FROM CTE
WHERE RN = 1
Result:
COD ID VALUE
----------- ----------- --------------------
28 2 Supermarket
29 2 School
30 1 NULL
Another option is to use the WITH TIES clause in concert with Row_Number()
Example
Select top 1 with ties *
from YourTable
Order By Row_Number() over (Partition By [COD] order by Value Desc)
Returns
COD ID VALUE
28 2 Supermarket
29 2 School
30 1 NULL
I would use GROUP BY and JOIN. If there is no NOT NULL value for a COD than it should be resolved using the OR in JOIN clause.
SELECT your_table.*
FROM your_table
JOIN (
SELECT COD, MAX(value) value
FROM your_table
GROUP BY COD
) gt ON your_table.COD = gt.COD and (your_table.value = gt.value OR gt.value IS NULL)
If you may have more than one non null value for a COD this will work
drop table MyTable
CREATE TABLE MyTable
(
COD INT,
ID INT,
VALUE VARCHAR(20)
)
INSERT INTO MyTable
VALUES (28,1, NULL),
(28,2,'Supermarket'),
(28,3,'School'),
(29,1,NULL),
(29,2,'School'),
(29,3,NULL),
(30,1,NULL);
WITH Dups AS
(SELECT COD FROM MyTable GROUP BY COD HAVING count (*) > 1 )
SELECT MyTable.COD,MyTable.ID,MyTable.VALUE FROM MyTable
INNER JOIN dups ON MyTable.COD = Dups.COD
WHERE value IS NOT NULL
UNION
SELECT MyTable.COD,MyTable.ID,MyTable.VALUE FROM MyTable
LEFT JOIN dups ON MyTable.COD = Dups.COD
WHERE dups.cod IS NULL
I have the following table:
Name | Col1 | Col2 | Col3
John A B C
John A D A
Bill A A D
Bill F A A
Steve F A B
Steve C C A
I want to know a total of how many As John, Bill, and Steve have...
e.g. John: 3, Bill: 4, Steve: 2
How could I do this using T-SQL? Thanks.
You can use the UNPIVOT function:
select name, count(val) TotalAs
from yourtable
unpivot
(
val
for col in (col1, col2, col3)
) u
where val = 'A'
group by name
See SQL Fiddle with Demo
Try this SQL Fiddle For below:
declare #table table (name varchar(10), c1 char(1), c2 char(1), c3 char(1))
insert into #table
SELECT 'John','A','B','C' UNION
SELECT 'John','A','D','A' UNION
SELECT 'Bill','A','A','D' UNION
SELECT 'Bill','F','A','A' UNION
SELECT 'Steve','F','A','B' UNION
SELECT 'Steve','C','C','A'
; WITH CTE AS
(
SELECT name,
(SELECT Count(CASE WHEN val = 'A' Then 1 ELse Null end)
FROM (VALUES (c1),(c2),(c3)) AS value(val)) As ACOL
from #table
)
SELECT Name, SUM(ACOL) ACount FROM CTE GROUP BY NAME
How about this for SQL Server 2012? It may be faster.
select name,sum(datalength(concat(col1,col2,col3))-
datalength(replace(concat(col1,col2,col3),'A','')))
from yourtable
group by name;
I have a following example - table with name, department and country. I need to create a select statement that lists all records and assigns unique number to each group of department and country (column Group in the example):
Name Department Country Group
====== ============ ========= =====
James HR UK 1
John HR UK 1
Alice Finance UK 2
Bob Finance DE 3
Frank Finance DE 3
I thought of some select with analytic function but I found only row_number() over (partition by department, country) which numbers records inside the group and not groups themselves. Do you have any idea how to solve this problem? Thank you!
SELECT t.*, q.grp
FROM (
SELECT q.*, rownum AS grp
FROM (
SELECT DISTINCT department, country
FROM mytable
ORDER BY
department, country
) q
) q
JOIN mytable t
ON t.department = q.department
AND t.country = q.country
or
SELECT t.*, DENSE_RANK() OVER (ORDER BY department desc, country desc) AS grp
FROM mytable
Its a bit clunky, but you could do a a sub query ( or in this case using the with clause ) on the table to get the distinct department per country then get the rownum from that.
set echo on
DROP TABLE TESTXX
DROP TABLE TESTXX succeeded.
CREATE
TABLE TESTXX
(
NAME VARCHAR2 ( 10 )
, DEPARTMENT VARCHAR2 ( 15 )
, COUNTRY VARCHAR2 ( 2 )
)
CREATE succeeded.
INSERT INTO TESTXX VALUES
( 'James', 'HR', 'UK'
)
1 rows inserted
INSERT INTO TESTXX VALUES
( 'John', 'HR', 'UK'
)
1 rows inserted
INSERT INTO TESTXX VALUES
( 'Alice', 'FI', 'UK'
)
1 rows inserted
INSERT INTO TESTXX VALUES
( 'Bob', 'FI', 'DE'
)
1 rows inserted
INSERT INTO TESTXX VALUES
( 'Frank', 'FI', 'DE'
)
1 rows inserted
.
WITH
X AS
(SELECT
XX.*
, ROWNUM R
FROM
(SELECT
DEPARTMENT
, COUNTRY
FROM
TESTXX
GROUP BY
COUNTRY
, DEPARTMENT
ORDER BY
COUNTRY DESC
, DEPARTMENT DESC
) XX
)
SELECT
T.*
, X.R
FROM
TESTXX T
INNER JOIN X
ON
T.DEPARTMENT = X.DEPARTMENT
AND T.COUNTRY = X.COUNTRY
ORDER BY
T.COUNTRY DESC
, T.DEPARTMENT DESC
NAME DEPARTMENT COUNTRY R
---------- --------------- ------- ----------------------
James HR UK 1
John HR UK 1
Alice FI UK 2
Bob FI DE 3
Frank FI DE 3
5 rows selected