I have a simple question that I wasn't really sure how to search for (or title!). I apologize if this has been asked a million times. For the following table, how do I generate a report that will detail the number of companies that a person has worked for and how many people have also worked for that same number? So, for example, this table should return:
people, companiesperperson
1, 1
2, 2
1, 3
for the following table called personalinfo:
id_number first last company
1 John Doe Intel
2 John Doe Microsoft
3 Phil Jenkins Amgen
4 Phil Jenkins Bayer
5 Phil Jenkins Sanofi
6 Josh Edwards Walgreens
7 Amy Dill URS
8 Amy Dill ARCADIS
Let me know if this is still confusing and if I can further clarify what I am looking to do.
Thanks!
This is a rough estimate of the query but
SELECT count as companiesperperson, COUNT(first, last) as people FROM
(SELECT COUNT(company) as count, first, last FROM personalinfo GROUP BY (first, last)) as a
GROUP BY count
To explain the query first in the subquery we are asking for the names and count of companies after splitting up all the rows by names
Then in the outer query we split up all the rows by their count and ask how many unique names can be found in each group.
There may be a few syntax errors I've left straggling but the group by feature is really what's essential to understanding how to solve this question.
Related
id_no doc_id item_no product customer
123 2 1 A Daisy
123 2 9 A Ben
123 4 3 A Daisy
123 4 4 A Ben
123 6 11 B Daisy
123 6 13 B Ben
when I put it in my report it results to
Daisy Daisy
Ben
And it is also the result in mysql
select distinct customer from receipt where id_no like '123'
result:
Daisy
Daisy
Ben
Another query that I tried:
select distinct id_no, customer, product from receipt where id_no like '123'
result:
123 Daisy A
123 Daisy B
123 Daisy A
123 Ben A
123 Ben B
desired result:
Daisy
Ben
Please help me please.
Thank you guys for the help I found out why the other one keeps on showing. It is because the other Daisy is spelled as Daissy that's why.
Most likely your Customer name contains additional characters between the two records. Depending on how the datatype is implemented, spaces could matter and have contributed to the difference.
Try concatenating a character before and after customer.
I am unfamiliar with the concepts in Crystal Reports, but from what I understand, you would have to create a formula like so:
"XXX" & {Receipt.Customer} & "XXX"
If you run it again, you might recognize there is additional space like so:
XXXDaisyXXX
XXXDaisy XXX
^____ Additional Space
There is no chance of error while you using distinct ..it should return distinct value ...any way you can try another way
SELECT customer FROM receipt WHERE id_no like '123' GROUP BY customer
I don't see why you are fetching three records. I tried implementing your database and ran your query. It returned the result as expected.
See the above pic. There may be some issue with the data type you used. You may try grouping via customer, but I don't think it should affect your result anyway.
Also Check if the data types match.
The selection you made from customer id and id_no is unique and with distinct it should return only two rows
plase try this code
i get solution
select distinct `customer` from receipt where `id_no`='123'
this is right
i tryied this is my past project
best of luck
My table lists every character from all 5 of George R. R. Martin's currently published A Song of Ice and Fire novels. Each row contains a record indicating which book in the series the character is from (numbered 1-5) and a single letter indicating the character's gender (M/F). For example:
A B C
1 Character Book Gender
------------------------------
2 Arya Stark - 1 - F
3 Eddard Stark - 1 - M
4 Davos Seaworth - 2 - M
5 Lynesse Hightower - 2 - F
6 Xaro Xhoan Daxos - 2 - M
7 Elinor Tyrell - 3 - F
I can use COUNTIF to find out that there are three females and three males in this table, but I want to know, for example, how many males there are in book 2. How could I write a formula that would make this count? Here is a pseudocode of what I'm trying to achieve:
=COUNTIF(C2:C7, Column B = '2' AND Column C = 'M')
This would output 2.
I'm aware that this task is far better suited to databases and a SELECT query, but I'd like to know how to solve this problem within the constraints of a LibreOffice Calc spreadsheet, without using a macro. Excel-based solutions are fine, so long as they also work in Calc. If there's no solution that uses COUNTIF, it doesn't matter, so long as it works.
I worked it out, thanks to a prompt by assylias. The COUNTIFS formula produces the result I want by counting multiple search criteria. For example, this formula works out how many male characters are in Book 1 (A Game of Thrones).
=COUNTIFS($A$2:$A$2102, "=1", $L$2:$L$2102, "=M")
My question about SEARCH query performance.
I've flattened out data into a read-only Person table (MySQL) that exists purely for search. The table has about 20 columns of data (mostly limited text values, dates and booleans and a few columns containing unlimited text).
Person
=============================================================
id First Last DOB etc (20+ columns)...
1 John Doe 05/02/1969
2 Sara Jones 04/02/1982
3 Dave Moore 10/11/1984
Another two tables support the relationship between Person and Activity.
Activity
===================================
id activity
1 hiking
2 skiing
3 snowboarding
4 bird watching
5 etc...
PersonActivity
===================================
id PersonId ActivityId
1 2 1
2 2 3
3 2 10
4 2 16
5 2 34
6 2 37
7 2 38
8 etc…
Search considerations:
Person table has potentially 200-300k+ rows
Each person potentially has 50+ activities
Search may include Activity filter (e.g., select persons with one and/or more activities)
Returned results are displayed with person details and activities as bulleted list
If the Person table is used only for search, I'm wondering if I should add the activities as comma separated values to the Person table instead of joining to the Activity and PersonActivity tables:
Person
===========================================================================
id First Last DOB Activity
2 Sara Jones 04/02/1982 hiking, snowboarding, golf, etc.
Given the search considerations above, would this help or hurt search performance?
Thanks for the input.
Horrible idea. You will lose the ability to use indexes in querying. Do not under any circumstances store data in a comma delimited list if you ever want to search on that column. Realtional database are designed to have good performance with tables joined together. Your database is relatively small and should have no performance issues at all if you index properly.
You may still want to display the results in a comma delimted fashion. I think MYSQL has a function called GROUP_CONCAT for that.
I have a little problem that I can´t solve. It´s really simple, but I just can´t figure it out and have search some time but not found any good answers.
I have two tables:
Transaction
t_nr (Primary) a_nr quantity
1 1 10
2 2 10
Customer
c_nr (PRIMARY) name city
1 Mario Tokyo
2 Luigi Beijing
And want to insert values from the two above into another table with one query looking
Account
a_nr (primary) c_nr
Problem is that when just making a regular select-from-statement it returns:
a_nr c_nr
1 1
1 2
2 1
2 2
i.e. not just merges them together in the account table.
a_nr c_nr
1 1
2 2
How do I do this?
Does a_nr correlate to c_nr (are they equal)?
If so,
insert into account (a_nr,c_nr)
SELECT transaction.a_nr, customer.c_nr from transaction, customer
WHERE transaction.a_nr = customer.c_nr
Although this seems completely pointless to only insert two values that are the same.
What is the desired output of Account?
My users answer two different questions, they are added to my answers_table as one row each. I'm trying to count how many users have answered my questions which seems simple at first. Count(*) and divide by 2. YES! But: the users can add new questions as they go, so suddenly there might be three questions, all answers/3 becomes an incorrect number of users if there was two questions for a while and then three, for example!
Can anyone figure out a query for doing this? So far I've got
SELECT COUNT(DISTINCT date) as totNum FROM login_answers
But it doesn't take the time in consideration. Meaning i just get the amount of answers in total for that day, not knowing how many questions was available that day.
Here's my table:
qid is the QuestionID so i guess thats somewhere to start?
id qid answer date deviceID
1502 2 2 2012-10-19 08:42:41 7
1503 1 3 2012-10-19 08:51:53 7
1504 2 2 2012-10-19 08:51:53 7
1505 1 4 2012-10-19 09:05:23 7
1506 2 2 2012-10-19 09:05:23 7
1507 1 4 2012-10-19 09:40:59 7
My proposed solution would be to store a session Id or some auto-generated key against the answers to uniquely identify a "session" of 2, 3 or more answers from a single person.
The query would simply be
SELECT COUNT(DISTINCT session_id) totNum
FROM login_answers
With your current schema with no identifiable key, it's quite hard to answer your question correctly if at all possible.