I am trying to find out how many of my rows are duplicates with any other row in my table.
Any help would be really appreciated
Select *
From DB
This gives me a count of all rows but I can’t figure out how to get only duplicates
If you don't provide more details then I can only answer in generic terms. You could create a query like this:
select
custom_key,
count(0) as occurrences
from
table
group by
custom_key
having
occurrences > 1
;
with custom_key being the field or fields which make a record unique or not.
Related
I know there has to be a simple answer to this question, but I am a total SQL noob. In my result set I have multiple results in one column that have one specific value that is repeated several times. In another column there is another value that needs to be added. Please see the attached photo for clarification.
I want to be able to find all of the values in Column B that correspond to 'A' and add them up for one result like shown. I want to be sure to delete the duplicates in Column A. Any help is greatly appreciated.
You're trying to SUM the values in column B and you're trying to group them by (GROUP BY) the value in column A when you do that. This is accomplished like so:
SELECT
col_a,
SUM(col_b)
FROM
My_Table
GROUP BY
col_a
I am new to VBA so I apologize in advance if this seems basic to you experts but I appreciate all of the help I can get.
I have a table containing a column of reference numbers that can grow or shrink weekly. I also have a query pulling back price list data that has changed since last week. The query results vary weekly. What I need to do is assign all of the query results to each reference number and have all of that end up in a make table. For example if there are 10 reference numbers and the query result is 10 rows then 100 lines would be added to the table (adding the reference number to the beginning of each row). This sounds like some sort of loop but your the experts, not me.
Thanks in advance!
You can solve it with a cross join. In a cross join you join two tables without specifying a join clause. Such a query returns all possible combinations of rows of the two tables (this is called a Cartesian product)
SELECT col_a, col_b INTO newTable
FROM table_a, table_b
If table_a contains 10 rows and table_b contains 5 rows, this returns 50 rows.
I have below query and by using that i can find out duplicates on particular
keys. I have 335 columns in table so query will be bigger if mention all column names in the query
select stone_id,charge_title,count(*) from table group by stone_id,charge_title having count(*) > 1
But i want to find out duplicates on all keys from table by better way.
Please suggest solution
I'm new to databases. I want to find the Duplicate records from the database table which is already created i.e. i m not concern about to prevent duplicate insertion but i wanted to know the duplicate records.
i tried with
Distinct
key word but it will show the records by removing duplicate data,
and after that i tried
unique index
which will say the the table name which are having duplicate records but not show or give duplicate records.
thanks in advance.
List the columns that make a record a duplicate and then group by them and count the occourances
select col1. col2
from your_table
group by col1, col2
having count(*) > 1
The having clause lists only those having more than one enry in the table.
Select Null as Empty from (select * from TblMetaData)
Looks like, it is trying to get null rows for the same number of rows in tblMetaData.
EDIT: This could be written as
SELECT Null AS Empty FROM tblMetaData
It will yield a result set with one column named Empty which only contains NULL values. The number of rows will be equal to the number of rows available in TblMetaData.
It looks like the result of one of two possible situations:
The developer was getting paid per line, and threw in that query. It was probably originally structured to take more than one line.
The developer was incompetent and this was the only way they could think of to generate a bunch of null values.
The query returns a null value from each line of the table, so the only real information in the result is the number of records in the table.
This can of course be found out a lot more efficently using:
select count(*) as Count from TblMetaData
It's possible that the developer was not at all aware of the count aggregate (or how to search the web) and tried to get the number of records while making the result as small as possible.
It often used in this expression
select * from TableA where exists
(select null from TableB where TableB.Col1=TableA.Col1)
it can be used to give the number of rows in the table TblMetaData with the column's name denoting the first letter of empty(in this case only).
like suppose you gave
Select Null as Empty from (select * from TblMetaData)
so it will give
E
n rows selected
here n is the number of rows in the table.
suppose you gave
Select Null as XYZ from (select * from TblMetaData)
then it would be same but the column's name would change like
X
n rows selected