I hava a problem with distinct In every row by id I have 100 results.
I must show results for hearrate for player_id = 1, but it's only show about 250 results. It must be about 400
SELECT city.player_id, city.team_id, country.gender, account.first_name,
account.last_name,
city.position,player.status,GROUP_CONCAT(DISTINCT(playing))
FROM account
JOIN player
ON account.id = player.account_id JOIN city
ON player.id = city.player_id JOIN player_activity
ON player.id = player_activity.player_id JOIN team
ON city.team_id = country.id
GROUP BY player.id;
Any idea why is this doing?
You are only grouping by 1 of the columns that is not being aggregated., MySQL lets you do this but it produces inconsistent results
Try:
select city.player_id, city.team_id, country.gender, account.first_name,
account.last_name,
city.position,player.status,GROUP_CONCAT(DISTINCT(playing))
FROM account
JOIN player
ON account.id = player.account_id JOIN city
ON player.id = city.player_id JOIN player_activity
ON player.id = player_activity.player_id JOIN team
ON city.team_id = country.id
GROUP BY city.player_id, city.team_id, country.gender, account.first_name,
account.last_name,
city.position,player.status
;
Logically, the information you are asking the SQL to give you doesn't make any sense. Your query is asking SQL to return an individual record per player.id, yet you are also specifying that you would like to see several other columns displayed with this information.
How would you expect SQL to display to you a list of rows for (teamId, gender, etc..) that all have multiple rows in the database, when each of their player.id's was lumped into a single result (row)?
In essence, the query you are attempting to execute is invalid for this reason, and SQL is behaving weird/throwing errors because of this. Assuming that you can't aggregate fields like teamId and gender, I think you are a bit confused on what you are wanting SQL to do for you. What you really are wanting is SQL to ORDER BY, not GROUP BY, because you would like to see your results categorized by player.id rather than lumped into it. If you change your "GROUP BY" to an "ORDER BY", I'm betting you will see the results you are asking for. Hope this helps.
Related
I've got a problem with MySQL select statement.
I have a table with different Department and statuses, there are 4 statuses for every department, but for each month there are not always every single status but I would like to show it in the analytics graph that there is '0'.
I have a problem with select statement that it shows only existing statuses ( of course :D ).
Is it possible to create temporary table with all of the Departments , Statuses and amount of statuses as 0, then update it by values from other select?
Select statement and screen how it looks in perfect situation, and how it looks in bad situation :
SELECT utd.Departament,uts.statusDef as statusoforder,Count(uts.statusDef) as Ilosc_Statusow
FROM ur_tasks_details utd
INNER JOIN ur_tasks_status uts on utd.StatusOfOrder = uts.statusNR
WHERE month = 'Sierpien'
GROUP BY uts.statusDef,utd.Departament
Perfect scenario, now bad scenario :
I've tried with "union" statements but i don't know if there is a possibility to take only "the highest value" for every department.
example :
I've also heard about
With CTE tables, but I don't really get how to use it. Would love to get some tips on it!
Thanks for your help.
Use a cross join to generate the rows you want. Then use a left join and aggregation to bring in the data:
select d.Departament, uts.statusDef as statusoforder,
Count(uts.statusDef) as Ilosc_Statusow
from (select distinct utd.Departament
from ur_tasks_details utd
) d cross join
ur_tasks_status uts left join
ur_tasks_details utd
on utd.Departament = d.Departament and
utd.StatusOfOrder = uts.statusNR and
utd.month = 'Sierpien'
group by uts.statusDef, d.Departament;
The first subquery should be your source of all the departments.
I also suspect that month is in the details table, so that should be part of the on clause.
NOTE: Just a practice problem.. NOT looking for free homework answers.
The practice problem I have asks to report the number of flights by plane’s year in ascending order of plane’s year. This requires the joining of two tables, the flights table and planes table. I believe the SQL should be relatively simple, and I think the main issue with mine is the vague select statement I currently have. I have looked at the different join methods, both explicit and implicit, and have also tried a left join with no luck.
If more table information is needed, I can share. The column the two tables share is year.
Also, very new here, so if there is something undesirable or incorrect about this post, please let me know.
select *,
count(*) as n_flights
from flights, planes
where flights.year = planes.year
order by planes.year asc
;
The output I am looking for:
The output I get:
Presumably, there is a column in the flights table that refers to the primary key of the planes table - let me assume plane_id: this is what you would use to join the tables.
Then, you want to aggregate by plane year, using a group by clause, and count the number of rows in each group:
select p.year, count(*) as n_flights
from flights f
inner join planes p on p.plane_id = f.plane_id
group by p.year
order by p.year
select planes.year, count(*)
from flights, planes
where flights.year = planes.year
group by planes.year
order by planes.year asc
I have two tables, one is 'points' which contains ID and points. The other table is 'name' and contains ID, Forename, and Surname.
I'm trying to search for the total number of points someone with the forename Anne, and surname Brown, scored.
Would I have to do a join? If so, is this correct?
SELECT Name.Forename, Name.Surname
FROM Name
FULL OUTER JOIN Points
ON Name.ID=Points.ID
ORDER BY Name.Forename;
But then I also have to add the points, so would I have to use:
SELECT SUM (`points`) FROM Points
Then there is also the WHERE statement so that it only searches for the person with this name:
WHERE `Forename`="Anne" OR `Surname`="Brown";
So how does this all come together (based on the assumption that you do something like this)?
SELECT Name.ID, Forename, Surname, SUM(Points)
FROM Name
INNER JOIN Points ON Name.ID = Points.ID
/* Optional WHERE clause:
WHERE Name.ForeName = 'Anne' AND Name.Surname='Brown'
*/
GROUP BY Name.ID, Name.Forename, Name.Surname
So, first, your answer:
select sum(points) as Points
from
Points
inner join Name on Name.ID = Points.ID
where
Name.Forename ='Anne' and Name.SurName='Brown'
Secondly, FULL JOINS are bad since they pull all values from both sets even those without matches. If you want to only return values that match your criteria (A & B) you must use an INNER JOIN.
Thirdly, here is the MySQL reference documentation on SQL statement syntax. Please consider reading up on it and familiarizing yourself at least with the basics like JOINs, aggregation (including GROUP BY and HAVING), WHERE clauses, UNIONs, some of the basic functions provided, and perhaps subqueries. Having a good base in those will get you 99% of the way through most MySQL queries.
You can write it like this with a subquery.
SELECT Name.Forename, Name.Surname, Name.ID,
(SELECT SUM (`points`) FROM Points where Points.ID = Name.ID) as total_points
FROM Name ORDER BY Name.Forename;
However, I would like to point out, that it appears that your linking of the tables is incorrect. I can not be completely sure without seeing the tables, but I imagine it should be where points.userid = name.id
I have 2 simple tables - Firm and Groups. I also have a table FirmGroupsLink for making connections between them (connection is one to many).
Table Firm has attributes - FirmID, FirmName, City
Table Groups has attributes - GroupID, GroupName
Table FirmGroupsLink has attributes - FrmID, GrpID
Now I want to make a query, which will return all those firms, that have less groups then #num, so I write
SELECT FirmID, FirmName, City
FROM (Firm INNER JOIN FirmGroupsLink ON Firm.FirmID =
FirmGroupsLink.FrmID)
HAVING COUNT(FrmID)<#num
But it doesn't run, I try this in Microsoft Access, but it eventually should work for Sybase. Please show me, what I'm doing wrong.
Thank you in advance.
In order to count properly, you need to provide by which group you are couting.
The having clause, and moreover the count can't work if you are not grouping.
Here you are counting by Firm. In fact, because you need to retrieve information about the Firm, you are grouping by FirmId, FirmName and City, so the query should look like this:
SELECT Firm.FirmID, Firm.FirmName, Firm.City
FROM Firm
LEFT OUTER JOIN FirmGroupsLink
ON Firm.FirmID = FirmGroupsLink.FrmID
GROUP BY Firm.FirmID, Firm.FirmName, Firm.City
HAVING COUNT(FrmID) < #num
Note that I replace the INNER JOIN by a LEFT OUTER JOIN, because you might want Firm which doesn't belongs to any groups too.
I have a database with a table for details of ponies, another for details of contacts (owners and breeders), and then several other small tables for parameters (colours, counties, area codes, etc.). To give me a list of existing pony profiles, with their various details given, i use the following query:
SELECT *
FROM profiles
INNER JOIN prm_breedgender
ON profiles.ProfileGenderID = prm_breedgender.BreedGenderID
LEFT JOIN contacts
ON profiles.ProfileOwnerID = contacts.ContactID
INNER JOIN prm_breedcolour
ON profiles.ProfileAdultColourID = prm_breedcolour.BreedColourID
ORDER BY profiles.ProfileYearOfBirth ASC $limit
In the above sample, the 'profiles' table is my primary table (holding the Ponies info), 'contacts' is second in importance holding as it does the owner and breeder info. The lesser parameter tables can be identified by their prm_ prefix. The above query works fine, but i want to do more.
The first big issue is that I wish to GROUP the results by gender: Stallions, Mares, Geldings... I used << GROUP BY prm_breedgender.BreedGender >> or << GROUP BY ProfileBreedGenderID >> before my ORDER BY line, but than only returns two results from all my available profiles. I have read up on this, and apparantly need to reorganise my query to accomodate GROUP within my primary SELECT clause. How to do this however, gets me verrrrrrry confused. Step by step help here would be fantabulous.
As a further note on the above - You may have noticed the $limit var at the end of my query. This is for pagination, a feature I want to keep. I shouldn't think that's an issue however.
My secondary issue is more of an organisational one. You can see where I have pulled my Owner information from the contacts table here:
LEFT JOIN contacts
ON profiles.ProfileOwnerID = contacts.ContactID
I could add another stipulation:
AND profiles.ProfileBreederID = contacts.ContactID
with the intention of being able to list a pony's Owner and Breeder, where info on either is available. I'm not sure how to echo out this info though, as $row['ContactName'] could apply in either the capacity of owner OR breeder.
Is this a case of simply running two queries rather than one? Assigning a variable $foo to the first run of the query, then just run another separate query altogether and assign $bar to those results? Or is there a smarter way of doing it all in the one query (e.g. $row['ContactName']First-iteration, $row['ContactName']Second-iteration)? Advice here would be much appreciated.
And That's it! I've tried to be as clear as possible, and do really appreciate any help or advice at all you can give. Thanks in advance.
##########################################################################EDIT
My query currently stands as an amalgam of that provided by Cularis and Symcbean:
SELECT *
FROM (
profiles
INNER JOIN prm_breedgender
ON profiles.ProfileGenderID = prm_breedgender.BreedGenderID
LEFT JOIN contacts AS owners
ON profiles.ProfileOwnerID = owners.ContactID
INNER JOIN prm_breedcolour
ON profiles.ProfileAdultColourID = prm_breedcolour.BreedColourID
)
LEFT JOIN contacts AS breeders
ON profiles.ProfileBreederID = breeders.ContactID
ORDER BY prm_breedgender.BreedGender ASC, profiles.ProfileYearOfBirth ASC $limit
It works insofar as the results are being arranged as I had hoped: i.e. by age and gender. However, I cannot seem to get the alias' to work in relation to the contacts queries (breeder and owner). No error is displayed, and neither are any Owners or Breeders. Any further clarification on this would be hugely appreciated.
P.s. I dropped the alias given to the final LEFT JOIN by Symcbean's example, as I could not get the resulting ORDER BY statement to work for me - my own fault, I'm certain. Nonetheless, it works now although this may be what is causing the issue with the contacts query.
GROUP in SQL terms means using aggregate functions over a group of entries. I guess what you want is order by gender:
ORDER BY prm_breedgender.BreedGender ASC, profiles.ProfileYearOfBirth ASC $limit
This will output all Stallions, etc. next to each other.
To also get the breeders contact, you need to join with the contacts table again, using an alias:
LEFT JOIN contacts AS owners
ON profiles.ProfileOwnerID = owners.ContactID
LEFT JOIN contacts AS breeders
ON profiles.ProfileBreederID = breeders.ContactID
To further expand on what #cularis stated, group by is for aggregations down to the lowest level of "grouping" criteria. For example, and I'm not doing per your specific tables, but you'll see the impact. Say you want to show a page grouped by Breed. Then, a user picks a breed and they can see all entries of that breed.
PonyID ProfileGenderID Breeder
1 1 1
2 1 1
3 2 2
4 3 3
5 1 2
6 1 3
7 2 3
Assuming your Gender table is a lookup where ex:
BreedGenderID Description
1 Stallion
2 Mare
3 Geldings
SELECT *
FROM profiles
INNER JOIN prm_breedgender
ON profiles.ProfileGenderID = prm_breedgender.BreedGenderID
select
BG.Description,
count(*) as CountPerBreed
from
Profiles P
join prm_BreedGender BG
on p.ProfileGenderID = BG.BreedGenderID
group by
BG.Description
order by
BG.Description
would result in something like (counts are only coincidentally sequential)
Description CountPerBreed
Geldings 1
Mare 2
Stallion 4
change the "order by" clause to "order by CountsPerBreed Desc" (for descending) and you would get
Description CountPerBreed
Stallion 4
Mare 2
Geldings 1
To expand, if you wanted the aggregations to be broken down per breeder... It is a best practice to group by all things that are NOT AGGREGATES (such as MIN(), MAX(), AVG(), COUNT(), SUM(), etc)
select
BG.Description,
BR.BreaderName,
count(*) as CountPerBreed
from
Profiles P
join prm_BreedGender BG
on p.ProfileGenderID = BG.BreedGenderID
join Breeders BR
on p.Breeder = BR.BreaderID
group by
BG.Description,
BR.BreaderName
order by
BG.Description
would result in something like (counts are only coincidentally sequential)
Description BreaderName CountPerBreed
Geldings Bill 1
Mare John 1
Mare Sally 1
Stallion George 2
Stallion Tom 1
Stallion Wayne 1
As you can see, the more granularity you provide to the group by, the aggregation per that level is smaller.
Your join conditions otherwise are obviously understood from what you've provided. Hopefully this sample clearly provides what the querying process will do. Your group by does not have to be the same as the final order... its just common to see so someone looking at the results is not trying to guess how the data was organized.
In your sample, you had an order by the birth year. When doing an aggregation, you will never have the specific birth year of a single pony to so order by... UNLESS.... You included the YEAR( ProfileYearOfBirth ) as BirthYear as a column, and included that WITH your group by... Such as having 100 ponies 1 yr old and 37 at 2 yrs old of a given breed.
It would have been helpful if you'd provided details of the table structure and approximate numbers of rows. Also using '*' for a SELECT is a messy practice - and will cause you problems later (see below).
What version of MySQL is this?
apparantly need to reorganise my query to accomodate GROUP within my primary SELECT clause
Not necessarily since v4 (? IIRC), you could just wrap your query in a consolidating select (but move the limit into the outer select:
SELECT ProfileGenderID, COUNT(*)
FROM (
[your query without the LIMIT]
) ilv
GROUP BY ProfileGenderID
LIMIT $limit;
(note you can't ORDER BY ilv.ProfileYearOfBirth since it is not a selected column / group by expression)
How many records/columns do you have in prm_breedgender? Is it just Stallions, Mares, Geldings...? Do you think this list is likely to change? Do you have ponies with multiple genders? I suspect that this domain would be better represented by an enum in the profiles table.
with the intention of being able to list a pony's Owner and Breeder,
Using the code you suggest, you'll only get returned instances where the owner and breeder are the same! You need to add a second instance of the contacts table with a different alias to get them all, e.g.
SELECT *
FROM (
SELECT *
FROM profiles
INNER JOIN prm_breedgender
ON profiles.ProfileGenderID = prm_breedgender.BreedGenderID
LEFT JOIN contacts ownerContact
ON profiles.ProfileOwnerID = ownerContact.ContactID
INNER JOIN prm_breedcolour
ON profiles.ProfileAdultColourID = prm_breedcolour.BreedColourID
) ilv LEFT JOIN contacts breederContact
ON ilv.ProfileBreederID = breederContact.ContactID
ORDER BY ilv.ProfileYearOfBirth ASC $limit