I am trying to write a query to find out whether a record exist more than one or not in a given period of time. And even if it exist, how many times the same record has been repeated.
Now to solve this issue, I have sorted the records.
select * from table_name where date = ? and date > ? order by email
And trying to count the number of times the same record exist.But I am not able to figure out a way to count the number of times the same record exists.
Here is a problem.The image below holds the basic data structure.
Here is the expected output for a year
The table above holds Xyz name and xyz#email.com data three times. And the name Abc and email abc#email.com two times and the third record name Def and email def#email.com two times. Now what I am trying to figure out a way to find out the number of times each records are being repeated in a given period of time using a single query. I am thinking to make use of recursion on a record and count till it didn't find a different record after sorting it. But using recursion on every records seems expensive.
Is there a better solution to solve this problem ?
Regards
Group and count.
SELECT column_to_compare1, column_to_compare2, COUNT(*)
FROM table_name
WHERE [date] BETWEEN #date1 AND #date2
GROUP BY column_to_compare1, column_to_compare2
HAVING COUNT(*) > 1 -- IF YOU WANT TO ONLY INCLUDE RECORDS WITH DUPLICATES
Between is inclusive, so you can adjust your dates with DATEADD if you really want between.
You can use the COUNT function to do this.
To do this using your own query:
SELECT Name, Email, COUNT(*) AS count
FROM table_name
WHERE date BETWEEN '01/01/2005' AND '31/12/2005'
GROUP BY Name, Email
However your example query is poor so I cannot give you a better solution. Here is an example of this working: SQL Fiddle
EDIT: Updated my solution to match you expected output.
Related
I have been struggling with creating a query in Access to select a distinct field with the criteria of having the newest entry in the database.
Heres a brief summary of how what my table conssists of. I have a table with surveying data collected from 2007 to the present. We have field with a survey marks name with corresponding adjustment data. In the corresponding data there is field with the adjusmtent date. Many of the marks have been occupied mutiple times and only want to retrieve the most recent occupation information.
Roughly i want to
SELECT DISTINCT STATUS_POINT_DESIGNATION
FROM __ALL_ADJUSTMENTS
WHERE [__ALL_ADJUSMENTS]![ADJ_DATE]=MAX(ADJ_DATE)
I seem to be getting confused how relate the select a distinct value with a constraint. Any Suggestions?
DH
Seems you could achieve your aim of getting the latest observation for each survey point by a summary function:
SELECT STATUS_POINT_DESIGNATION, Max(ADJ_DATE) AS LatestDate, Count(STATUS_POINT_DESIGNATION) AS Observations
FROM __ALL_ADJUSTMENTS
GROUP BY STATUS_POINT_DESIGNATION;
I'm trying to count the number of actions per account over a period of time. The period of time may be variable. The way I've thought of doing this is by creating a table for each time period, containing records for each account that get upserted on user action. For example, I'd have a table named '12-05-2013' which would contain a record w/ the following attributes:
{
"account_id" = uniqueid12345,
"uploads" = 4
}
The table would basically represent the uploads by all users on that specific day.
I want to be able to find all accounts that had < 2 uploads over the last seven days. This would require me to query over the 7 tables representing the last 7 days. (IE 12-05-2013, 12-04-2013, 12-03-2013, etc). So far I've been unable to find a method of selecting out of these specific tables. Am I modeling the problem wrong? Is there an easy way to do this? I'm new to relational databases so go easy on me :)
Why wouldn't you use a query such as this?
select userid, count(*) as NumActions
from ActionTable
where ActionDate bewteen #date1 and #date2;
I have a table that stores zone_id. Sometimes a zone id is twice in the database. I wrote a query to show only entries that have two or more entries of the same zone_id in the table.
The following query returns the correct result:
select *, count(zone_id)
from proxies.storage_used
group by zone_id desc
having count(zone_id) > 1;
However, if I group by last_updated or company_id, it returns random values. If I don't add a group by clause, it only displays one value as per the screenshot below. First output shows above query string, second output shows same query string without the 'group by' line and returns only one value:
correction: I'm a new member and thus can't post pictures directly, so I added it on minus: http://min.us/m3yrlkSMu#1o
While my query works, I don't understand why. Can somebody help me understand why group by is altering the actual output, instead of only the grouping of the output? I am using MySQL.
A group by divides the resulting rows into groups and performs the aggregate function on the records in each group. If you do a count(*) without a group by you will get a single count of all rows in a table. Since you didn't specify a group by there is only one group, all records in the table. If you do a count(*) with a group by of zone id, you will get a count of how many records there are for each zone id. If you do a count(*) of zone id and last updated date, you will get a count of how many rows were updated on each date in each zone.
Without a group by clause, everything is stored in the same group, so you get a single result. If there are more than one row in your table, then the having will succeed. So, you'll end up counting all the rows in your table...
source
From what I got, you could create a query with having and without group by only in two situations:
You have a where clause, and you want to test a condition on an aggregation of all rows that satisfy that clause.
Same as above, but for all rows in your table (in practice, it doesn't make sense, though).
I need to write a SQL query that pulls from a table that stores records for each time one of our salespeople speaks to a client. The relevant columns are: (1) the salesperson's employee ID, (2) the client's account number, and (2) the date of the conversation.
It's often the case that salespeople have spoken to clients multiple times within the report period (a calendar month) so there will be several entries that are nearly identical except for the date.
Where I'm getting tripped up is that, for the purpose of this query, I need to return only one record per salesperson/client combination, but I can't use DISTINCT because I need to include the date of the most recent conversation within the reporting period.
So, if salesperson John has spoken to client ABC on 10/10, 10/18, and 10/25 I need to pull the 10/25 record but not the others.
It's a Sybase database.
I have the feeling that I may be missing something simple here but I've tried searching and remain stumped. Any help is greatly appreciated.
Thanks for your time,
John
Guessing at the column names...
SELECT employee_id, client_acct_no,
MAX(conversation_date) AS MOST_RECENT_CONV_DATE
FROM mytable
WHERE conversation_date BETWEEN DATE '2010-10-01' AND DATE '2010-10-31'
GROUP BY employee_id, client_acct_no
Documentation for GROUP BY clause.
For a user logging table I have in a SQL database, I track the some of the parameters off of a report request. The report allows multiple ID's to be passed to it and I store all of those in a single column in the database column. If this were to be a normalized set of data, there would definitely be an additional table setup for this, but this is what was inherited...
I've now been asked to give a quick count of the number of times a report was run with more than 2 ID's passed to it. I can easily get the number of records that have more than 1 report requested because they all include a comma.
What I need to do next is count the number of times a comma appears in a column. How do you do this in SQL?
--count the number of times more than 1 report was requested in the record
select
count(*) as cnt
from
[table]
where
RequestedReportParams Like '%,%'
SELECT LEN(RequestedReportParams) - LEN(REPLACE(RequestedReportParams, ',', ''))
FROM YourTable
WHERE .....
This is simply comparing the length of the column with the commas, with the length of the value with the commas removed, to give you the difference (i.e. the number of commas)
It seems the quick and dirty way to answer the question you've been asked would be to do this:
select
count(*) as cnt
FROM
[table]
WHERE
RequestedReportParams Like '%,%,%'