I am validating a table which has a transaction level data of an eCommerce site and find the exact errors.
I want your help to find duplicate records in a 50 column table on SQL Server.
Suppose my data is:
OrderNo shoppername amountpayed city Item
1 Sam 10 A Iphone
1 Sam 10 A Iphone--->>Duplication to be detected
1 Sam 5 A Ipod
2 John 20 B Macbook
3 John 25 B Macbookair
4 Jack 5 A Ipod
Suppose I use the below query:
Select shoppername,count(*) as cnt
from dbo.sales
having count(*) > 1
group by shoppername
will return me
Sam 2
John 2
But I don't want to find duplicate just over 1 or 2 columns. I want to find the duplicate over all the columns together in my data. I want the result as:
1 Sam 10 A Iphone
with x as (select *,rn = row_number()
over(PARTITION BY OrderNo,item order by OrderNo)
from #temp1)
select * from x
where rn > 1
you can remove duplicates by replacing select statement by
delete x where rn > 1
SELECT OrderNo, shoppername, amountPayed, city, item, count(*) as cnt
FROM dbo.sales
GROUP BY OrderNo, shoppername, amountPayed, city, item
HAVING COUNT(*) > 1
SQL> SELECT JOB,COUNT(JOB) FROM EMP GROUP BY JOB;
JOB COUNT(JOB)
--------- ----------
ANALYST 2
CLERK 4
MANAGER 3
PRESIDENT 1
SALESMAN 4
Just add all fields to the query and remember to add them to Group By as well.
Select shoppername, a, b, amountpayed, item, count(*) as cnt
from dbo.sales
group by shoppername, a, b, amountpayed, item
having count(*) > 1
To get the list of multiple records use following command
select field1,field2,field3, count(*)
from table_name
group by field1,field2,field3
having count(*) > 1
Try this instead
SELECT MAX(shoppername), COUNT(*) AS cnt
FROM dbo.sales
GROUP BY CHECKSUM(*)
HAVING COUNT(*) > 1
Read about the CHECKSUM function first, as there can be duplicates.
Try this
with T1 AS
(
SELECT LASTNAME, COUNT(1) AS 'COUNT' FROM Employees GROUP BY LastName HAVING COUNT(1) > 1
)
SELECT E.*,T1.[COUNT] FROM Employees E INNER JOIN T1 ON T1.LastName = E.LastName
with x as (
select shoppername,count(shoppername)
from sales
having count(shoppername)>1
group by shoppername)
select t.* from x,win_gp_pin1510 t
where x.shoppername=t.shoppername
order by t.shoppername
First of all, I doubt that the result it not accurate? Seem like there are Three 'Sam' from the original table. But it is not critical to the question.
Then here we come for the question itself. Based on your table, the best way to show duplicate value is to use count(*) and Group by clause. The query would look like this
SELECT OrderNo, shoppername, amountPayed, city, item, count(*) as RepeatTimes FROM dbo.sales GROUP BY OrderNo, shoppername, amountPayed, city, item HAVING COUNT(*) > 1
The reason is that all columns together from your table uniquely identified each record, which means the records will be considered as duplicate only when all values from each column are exactly the same, also you want to show all fields for duplicate records, so the group by will not miss any column, otherwise yes because you can only select columns that participate in the 'group by' clause.
Now I would like to give you any example for With...Row_Number()Over(...), which is using table expression together with Row_Number function.
Suppose you have a nearly same table but with one extra column called Shipping Date, and the value may change even the rest are the same. Here it is:
OrderNo shoppername amountpayed city Item Shipping Date
1 Sam 10 A Iphone 2016-01-01
1 Sam 10 A Iphone 2016-02-02
1 Sam 5 A Ipod 2016-03-03
2 John 20 B Macbook 2016-04-04
3 John 25 B Macbookair 2016-05-05
4 Jack 5 A Ipod 2016-06-06
Notice that row# 2 is not a duplicate one if you still take all columns as a unit. But what if you want to treat them as duplicate as well in this case? You should use With...Row_Number()Over(...), and the query would look like this:
WITH TABLEEXPRESSION
AS
(SELECT *,ROW_NUMBER() OVER (PARTITION BY OrderNo, shoppername, amountPayed, city, item ORDER BY [Shipping Date] as Identifier) --if you consider the one with late shipping date as the duplicate
FROM dbo.sales)
SELECT * FROM TABLEEXPRESSION
WHERE Identifier !=1 --or use '>1'
The above query will give result together with Shipping Date, for example:
OrderNo shoppername amountpayed city Item Shipping Date Identifier
1 Sam 10 A Iphone 2016-02-02 2
Note this one is different from the one with 2016-01-01, and the reason why 2016-02-02 has been filtered out is PARTITION BY OrderNo, shoppername, amountPayed, city, item ORDER BY [Shipping Date] as Identifier, and Shipping Date is NOT one of the column that need to be took care of for duplicate records, which means the one with 2016-02-02 still could be a perfect result for your question.
Now summarize it little bit, using count(*) and Group by clause together is the best choice when you only want to show all columns from Group byclause as the result, otherwise you will miss the columns that do not participate in group by.
While For With...Row_Number()Over(...), it is suitable in every scenario that you want to find duplicate records, however, it is little bit complicated to write the query and little bit over engineered compared to the former one.
If your purpose is to delete duplicate records from table, you have to use the later WITH...ROW_NUMBER()OVER(...)...DELETE FROM...WHERE one.
Hope this helps!
You can use below methods to find the output
with Ctec AS
(
select *,Row_number() over(partition by name order by Name)Rnk
from Table_A
)
select Name from ctec
where rnk>1
select name from Table_A
group by name
having count(*)>1
Select *
from dbo.sales
group by shoppername
having(count(Item) > 1)
Select EventID,count() as cnt
from dbo.EventInstances
group by EventID
having count() > 1
The following is running code:
SELECT abnno, COUNT(abnno)
FROM tbl_Name
GROUP BY abnno
HAVING ( COUNT(abnno) > 1 )
Related
Given this data
id Name group
1 Jhon 001
2 Paul 002
3 Mary 001
How can I get the duplicates values showing all the fields? The duplicate is only on group, id and name won't be duplicates.
Should end up looking like one of those (any would be valid):
:::::::::::::::::::::::::::::::::::::::::::::::
group count values
001 2 1,3
:::::::::::::::::::::::::::::::::::::::::::::::
id name group
1 Jhon 001
3 Mary 001
I tried with
SELECT
group, COUNT(*)
FROM
people
GROUP BY
group
HAVING
COUNT(*) > 1
But if I try to add id and name to the group by, it won´t find any duplicate.
Thanks in advance.
Try this.
SELECT Id, Name, [Group]
FROM people
WHERE [Group] IN(
SELECT [Group]
FROM people
GROUP BY [Group]
HAVING COUNT(*) > 1)
I would do an inner query to find the groups with more than one member, and then use that inner query to bring back a list of the names.
For example:
SELECT Id, Name, group
FROM people
WHERE group in
(SELECT group
FROM people
GROUP BY group
HAVING count(*) > 1);
Avoid using Group because it is a reserved keyword in SQL :
SELECT *
FROM MyTable
WHERE groups IN(
SELECT groups
FROM MyTable
GROUP BY groups
HAVING COUNT(*) > 1)
Check Execution here
Just use exists:
select p.*
from people p
where exists (select 1
from people p2
where p2.group = p.group and
p2.id <> p.id
);
This should be the most performant solution. With an index on people(group, id), it should have very good performance.
Note: All the advice to avoid using group as a column name is good advice. You should change the name.
In below table, I need to select duplicate records where all columns are duplicate except Customer Type and Price for a particular week.
For e.g
Week Customer Product Customer Type Price
1 Alex Cycle Consumer 100
1 Alex Cycle Reseller 101
2 John Motor Consumer 200
3 John Motor Consumer 200
3 John Motor Reseller 201
I am using below query but this query doesn't show me both costumer type, it just shows me consumer count(*) for a combination.
select Week, Customer, product, count(distinct Customer Type)
from table
group by Week, Customer, product
having count(distinct Customer Type) > 1
I would like to see below result, that shows me duplicate values and not just the count(*) of duplicate row. I am trying to see customers assigned to multiple customer types in a particular week for a product and at the same time show me all columns. It doesn't matter if the price is different.
Week Customer Product Customer Type Price
1 Alex Cycle Consumer 100
1 Alex Cycle Reseller 101
3 John Motor Consumer 200
3 John Motor Reseller 201
Thanks
Shaki
WITH CustomerDistribution_CTE (WeekC ,CustomerC, ProductC)
AS
(
select Week, Customer, product
from Your_Table_Name group by Week, Customer,
product having count(distinct CustomerType) > 1
)
SELECT Y.*
FROM CustomerDistribution_CTE C
inner join Your_Table_Name Y on C.WeekC =Y.Week
and C.CustomerC =Y.Customer and C.productC =Y.product
Note :Please replace "Your_Table_Name" with exact table name and Try.
One way to achieve this, using generic SQL, is to use a "derived table" like this:
select x.*
from tablex x
inner join (
select Week, Customer, Product
from tablex
group by Week, Customer, Product
having count(*) > 1
) d on x.Week = d.Week and x.Customer = d.Customer and x.Product = d.Product
You can do that by using DISTINCT like
select DISTINCT Customer,Product,Customer_Type,Price from Your_Table_Name
will look for DISTINCT combination.
Note: This query if of SQL Server
From the expected result that you have pasted, it looks like you are not concerned about the week.
If you have a ID (incremental PK), it would be much simpler like below
select * from table where ID not in
(select max(ID) from table group by Customer, Product, CustomerType having count(*) > 1 )
This is tested on MySQL. Do you have a ID column?
In case you don't have a ID column, try the below:
select max(week) week, Customer, Product, CustomerType, max(price) from device group by Customer, Product, CustomerType;
I have not verified this one.
This will return your expected result set:
select *
from table
-- Teradata syntax to filter the result of an OLAP-function
-- (similar to HAVING after GROUP BY)
qualify
count(*)
over (partition by Week, Customer, product) > 1
For other DBMSes you will need to nest your query:
select *
from
(
select ...,
count(*)
over (partition by Week, Customer, product) as cnt
from table
) as dt
where cnt > 1
Edit:
After re-reading your description above Select might be not exactly what you want, because it will also return rows with a single type. Then switch to:
select *
from table
-- Teradata syntax to filter the result of an OLAP-function
-- (similar to HAVING after GROUP BY)
qualify -- at least two different types:
min(Customer_Type) over (partition by Week, Customer, product)
<> max(Customer_Type) over (partition by Week, Customer, product)
I have an sql table with the below columns
OrderNo, GroupNum, ShipMethod, TrackingNo
I want to find number of orders that have multiple 'ShipMethod' for same groupnum?
Sample records wourld be:
Order123 1 DHL
Order123 2 DHL1
Order123 2 Fedex
Then i need to get result stating 2 or if possible output as below:
OrderNumer GroupNum Count
---------- ------- -----
Order123 2 2 (Because 2 shipmethods)
Group by the columns you want to be unique, use count() to get each groups count and use having to limit the output to only the relevant groups
select ordernum, groupnum, count(*) as cnt
from your_table
group by ordernum, groupnum
having count(*) > 1
If I understand correctly:
select OrderNumer, groupnum, count(*)
from t
group by OrderNumer, groupnum
having count(*) > 1;
You may also want count(distinct shipmethod), if you want to count the distinct values rather than the number of rows.
I have a table employee with columns (state_cd,emp_id,emp_name,ai_cd) how can i display disticnt state_cd with 3 different values from ai_cd
the answer should be
state_cd ai_cd
------- --------
TX 1
2
5
CA 9
10
11
This type of operation is normally better done in the application. But, you can do it in the query, if you really want to:
select (case when row_number() over (partition by state_cd order by ai_cd) = 1
then state_cd
end) as state_cd,
ai_cd
from employee e
order by e.state_cd, e.ai_cd;
The order by is very important, because SQL result sets are unordered. Your result requires ordering in order to make sense.
Just group by state_id and then count using count(Distinct column_name_)
select state_id from (select state_id,COUNT(DISTINCT ai_cd) as cnt from employee group by state_id) where cnt==3
Does anyone happen to know a way of basically taking the 'Distinct' command but only using it on a single column. For lack of example, something similar to this:
Select (Distinct ID), Name, Term from Table
So it would get rid of row with duplicate ID's but still use the other column information. I would use distinct on the full query but the rows are all different due to certain columns data set. And I would need to output only the top most term between the two duplicates:
ID Name Term
1 Suzy A
1 Suzy B
2 John A
2 John B
3 Pete A
4 Carl A
5 Sally B
Any suggestions would be helpful.
select t.Id, t.Name, t.Term
from (select distinct ID from Table order by id, term) t
You can use row number for this
Select ID, Name, Term from(
Select ID, Name, Term, ROW_NUMBER ( )
OVER ( PARTITION BY ID order by Name) as rn from Table
Where rn = 1)
as tbl
Order by determines the order from which the first row will be picked.