I've four tables:
characters
guid
name
gender
class
race
online
character_arena_stats
guid
personal_rating
matchmaker_rating
arena_team_member
arenateamid
played_season
played_week
wons_season
wons_week
arena_team
arenateamid
captain_guid
and I need to get character details(race,class,name,gender,online) and team information(personal_rating,matchmaker_rating,played_season,played_week,wons_season,wons_week,captain_guid), but can't get it working. My query is:
$result=mysql_query("SELECT
c.guid,
c.name,
c.gender,
c.class,
c.online,
c.race,
atm.guid,
atm.played_season,
atm.played_week,
atm.wons_season,
atm.wons_week,
atm.arenateamid,
cas.personal_rating,
cas.guid,
cas.matchmaker_rating,
at.arenateamid,
at.captainguid
FROM
character_arena_stats cas,
arena_team_member atm,
characters c,
arena_team at
WHERE c.guid = cas.guid AND atm.arenateamid = ".$entry." AND at.arenateamid = ".$entry."");
It should return only members whose guid is equal to c.guid, cas.guid, atm,guid and those, whose atm.arenateamid is equal to at.arenateamid. Insted, it returns a lot of random members.
Thanks and sorry for my english.
Since you're not specifying how records in the arena tables should join to records in the character tables, you're getting a cross join, which returns every combination of character records with arena records.
When you say "I want to get them all," what exactly do you mean? Find a starting point for your query. For example: are you looking for all characters, organized by team, with their details and arena stats? Or, for each character, all the teams on which they participate?
Defining the requirements a little more clearly will help us suggest solutions. :)
Update: Actually, having read the query a little more closely, I believe I can infer what you're looking for:
SELECT
c.guid,
c.name,
c.gender,
c.class,
c.online,
c.race,
atm.guid
atm.played_season,
atm.played_week,
atm.wons_season,
atm.wons_week,
atm.arenateamid,
cas.personal_rating,
cas.guid,
cas.matchmaker_rating,
at.arenateamid,
at.captainguid
FROM
character_arena_stats cas,
arena_team_member atm,
characters c,
arena_team at
WHERE c.guid = cas.guid
and c.guid = atm.guid
and atm.arenateamid = at.arenateamid
AND at.arenateamid = ".$entry."
Note that the Arena Team and Character tables are now joined based on the team captain's GUID - this will avoid the cross join ("random rows") problem. Also, Arena Team Members is now joined to Arena Teams, and the filter parameter is only checked against the Teams table.
Not sure this will give you precisely what you want without knowing more about your data and requirements - I believe what it will give you is a list of each team captain, their arena stats, along with their team and team members' stats. Hopefully this will move you forward. Good luck!
uhh mate not sure what you got there,... to lazy myself to write the query for you, have a look again at dev.mysql.com refs should be straight forwared.
also your character_arena_stats table, shouldn't there be a ref to a arena table or something?
guid
arena_id ?
personal_rating
matchmaker_rating
see more here for normalization
Yeah, I am not really sure exactly what you're trying to do, but based on the description ...
Your Model seems to be all wrong and will never produce the results you are looking for. For instance, there are no Keys tying arena_team and arena_team_member to characters and character_arena_stats.
Secondly, this condition:
"WHERE c.guid = cas.guid AND atm.arenateamid = ".$entry." AND at.arenateamid = ".$entry);
is incorrect for this statement: "It should return only members ... whose atm.arenateamid is equal to at.arenateamid".
Rather, it could be rewritten as follows:
"WHERE c.guid = cas.guid AND atm.arenateamid = at.arenateamid AND atm.arenateamid = ".$entry);
Regardless though, because of the aforementioned reasons, the query will never returned expected results, at least based on what I understood from your post.
SIDE NOTE: This is PHP code, so I do not know why you are tagging it as jQuery.
Good Luck,
Related
I have the following SQL-code in my (SAP IdM) Application:
Select mcmskeyvalue as MKV,v1.searchvalue as STARTDATE, v2.avalue as Running_Changes_flag
from idmv_entry_simple
inner join idmv_value_basic_active v1 on mskey = mcmskey and attrname = 'Start_of_company_change'
and mcentrytype = 'MX_PERSON' and to_date(v1.searchvalue,'YYYY-MM-DD')<= sysdate+3
left join idmv_value_basic v2 on v2.mskey = mcmskey and v2.attrname = 'Running_Changes_flag'
where mcmskey not in (Select mskey from idmv_value_basic_active where attrname = 'Company_change_running_flag')
I already found the solution for the ORA-01841 problem, as it could either be a solution similar to MSSQLs try_to_date as mentioned here: How to handle to_date exceptions in a SELECT statment to ignore those rows?
or a solution where I change the code to something like this, to work soly on strings:
Select mcmskeyvalue as MKV,v1.searchvalue as STARTDATE, v2.avalue as Running_Changes_flag
from idmv_entry_simple
inner join idmv_value_basic_active v1 on mskey = mcmskey and attrname = 'Start_of_company_change'
and mcentrytype = 'MX_PERSON' and v1.searchvalue<= to_char(sysdate+3,'YYYY-MM-DD')
left join idmv_value_basic v2 on v2.mskey = mcmskey and v2.attrname = 'Running_Changes_flag'
where mcmskey not in (Select mskey from idmv_value_basic_active where attrname = 'Company_change_running_flag')
So for the actually problem I have a solution.
But now I came into discussion with my customers and teammates why the error happens at all.
Basically for all entries of idmv_value_basic_activ that comply to the requirement of "attrname = 'Start_of_company_change'" we can be sure that those are dates. In addition, if we execute the query to check all values that would be delivered, all are in a valid format.
I learned in university that the DB-Engine could decide in which order it will run individual segments of a query. So for me the most logical explanation would be that, on the development environment (where we face the problem), the section " to_date(v1.searchvalue,'YYYY-MM-DD')<= sysdate+3” is executed before the section “attrname = 'Start_of_company_change'”
Whereas on the productive environment, where everything works like a charm, the segments are executed in the order that is descripted by the SQL Statement.
Now my Question is:
First: do I remember that right, since the teacher said that only once and at that time I could not really make sense out of it
And Second: Is this assumption of mine correct or is there another reason for the problem?
Borderinformation:
The Tool uses a kind of shifted data structure which is why there can be quite a few different types in the actual “Searchvalue” column of the idmv_value_basic_activ view. The datatype on the database layer is always a varchar one.
"the DB-Engine could decide in which order it will run individual segments of a query"
This is correct. A SQL query is just a description of the data you want and where it's stored. Oracle will calculate an execution plan to retrieve that data as best it can. That plan will vary based on any number of factors, like the number of actual rows in the table and the presence of indexes, so it will vary from environment to environment.
So it sounds like you have an invalid date somewhere in your table, so to_date raises an exception. You can use validate_conversion to find it.
here are my tables, im using sql developer oracle
Carowner(Carowner id, carowner-name,)
Car (Carid, car-name, carowner-id*)
Driver(driver_licenceno, driver-name)
Race(Race no, race-name, prize-money, race-date)
RaceEntry(Race no*, Car id*, Driver_licenceno*, finishing_position)
im trying to list to do the query below
which drivers have come second in races from the start of this year.
lncluding race name, driver name, and the name of the car in the output
i have attempted
select r.racename, d.driver-name, c.carowner-name
from race r, driver d, car c, raceentry re
where re.finishing_position = 2 and r.race-date is ...
Something like:
select r.racename, d.driver-name, c.carowner-name
from race r
join raceentry re on r.race_no = re.race_no
join car c on re.car_Id = c.car_id
join driver d on re.driverliscenceNo = d.driverliscenceNo
where re.finishing_position = 2 and r.race-date >='20130101'
This assumes only one car and one driver with a finsih place of 2nd in a particular race. You may need more conditions otherwise. If this is your own table design, you need to start right now learning to be consistent in your nameing between tables. It is important. Fields that are in multiple tables should have the same name and data type. Also you need to stop using implicit syntax. This ia aSQL antipattern and a very poor programming technique. It leads to mistakes such as accidental cross joins and is harder to read and maintain when things get more complex. As you are clearly learning, you need to stop this bad habit right now.
First off, multiple joins in the where clause are hard to get used to when you define more than 3 or 4 tables IMHO.
Do this instead:
Select
a.columnfroma
, b.columnfromb
, c.columnfromc
from tablea a
join tableb b on a.columnAandBShare = b.columnAandBShare
join tablec c on b.columnBandCShare = c.columnBandCShare
This while no one would say is a method you have to use, it is a much more readable method of performing joins.
Otherwise you are doing the joins in the where clause and if you have other predicates with your joins you are going to have to comment out which is which if you ever need to go back and look at it.
I have been given a database, the structure and data values are all unchangable and have been provided with a question.
Produce a query to list the holiday code, holiday description, holiday duration and site description for all holidays which visit site code 101. Your answer must not assume that site code 101 will always have the same site description.
I am confused on how to tackle this question. I have tried Multiple joins, different dot notation and googled the question to hell and back. Any help?
Table 1 - Holiday_Details
Holiday_Code - Country_Visited - Holiday_Duration - Holiday_Desc - Rating_Code - Cost
Table 2 - Site_Of_Holiday
Site_Description - Site_Code
Table 3 - Site_Visited
Holiday_Code - Site_Code
Comments have asked for previous attempts. This was my first.
SELECT holiday_code,
holiday_desc,
holiday_duration site_of_holiday.Site_Name
FROM holiday_details
JOIN site_visited
ON holiday_code = site_visited.holiday_code
JOIN site_of_holiday
ON site_visited.site_code = site_of_holiday.site_code
WHERE site_of_holiday.site_code = 101;
For future reference, you'll get a better response if you post a lot more detail about your failed attempts. By that, I mean code. Using SO to solve your homework assignments is frowned upon but, like a commenter said, once you've wracked your brain we're willing to help.
You seem like you may have actually tried real hard, so I'll throw you a bone...
The trick to navigating multiple tables is to find the "pairs" of matching columns. In this case you want to find a path between the tables Site_Of_Holiday (which has Site_Description) and Holiday_Details (which has everything else).
The columns that match between each pair of tables are:
Holiday_Code is found in both Site_Visited and Holiday_Details
Site_Code is found in both Site_Of_Holiday and Site_Visited
This allows you to build a path between the tables that contain all of the columns we want in the output. You would do this, in this case, using INNER JOINs across those matching column pairs.
Once you've joined the tables, think of the result like a giant table whose columns include all columns from all three tables (prefixed with whatever you 'name' the table during the joins). Now you just filter on the Site_Code with the usual WHERE clause.
Here's the full example - let me know if it works for you:
SELECT hd.Holiday_Code, hd.Holiday_Desc, hd.Holiday_Duration, soh.Site_Description
FROM Holiday_Details hd
INNER JOIN Site_Visited sv ON hd.Holiday_Code = sv.Holiday_Code
INNER JOIN Site_Of_Holiday soh ON sv.Site_Code = soh.Site_Code
WHERE sv.Site_Code = 101
Good luck!
P.S. In case any Americans get a similar assignment, here's the translation ;-)
SELECT vd.Vacation_Code, vd.Vacation_Desc, vd.Vacation_Duration, sov.Site_Description
FROM Vacation_Details vd
INNER JOIN Site_Visited sv ON vd.Vacation_Code = sv.Vacation_Code
INNER JOIN Site_Of_Vacation sov ON sv.Site_Code = sov.Site_Code
WHERE sv.Site_Code = 101
I am new to this portal. I have a very simple problem to be solved. It is related to the ANSI SQL. I am writing a reports using BIRT and I am fetching the data from several tables. I understand how the SQL joins work but maybe not fully. I researched google for hours and I could not find relevant answer.
My problem is that one of the relationships in the code produce a duplicate result (the same row is copied - duplicated). I was so determined to solve it I used every type of join available. Some of this SQL was produced already. I shall post my code below. I know that one of the solutions to my problem is use of the 'DISTINCT' keyword. I have used it and it does not solve my problem.
Can anyone propose any solution to that?
Sample code:
SELECT DISTINCT
partmaster.partdesc,
partmaster.uom,
traders.name AS tradername,
worksorders.id AS worksorderno,
worksorders.partid,
worksorders.quantity,
worksorders.duedate,
worksorders.traderid,
worksorders.orderid,
routingoperations.partid,
routingoperations.methodid,
routingoperations.operationnumber,
routingoperations.workcentreid,
routingoperations.settime,
routingoperations.runtime,
routingoperations.perquantity,
routingoperations.description,
routingoperations.alternativeoperation,
routingoperations.alternativeoperationpreference,
machines.macdesc,
machines.msection,
allpartmaster.partnum,
allpartmaster.nbq,
allpartmaster.partdesc,
routingoperationtools.toolid,
tools.tooldesc,
CAST (emediadetails.data as VARCHAR(MAX)) AS cplandata
FROM worksorders
INNER JOIN partmaster ON worksorders.partid = partmaster.partnum
INNER JOIN traders traders ON worksorders.traderid = traders.id
INNER JOIN routingoperations routingoperations ON worksorders.partid = routingoperations.partid
AND worksorders.routingmethod = routingoperations.methodid
INNER JOIN allpartmaster allpartmaster ON routingoperations.partid = allpartmaster.partnum
LEFT OUTER JOIN machines machines ON routingoperations.workcentreid = machines.macid
LEFT OUTER JOIN routingoperationtools routingoperationtools ON routingoperationtools.partid = routingoperations.partid
AND routingoperationtools.routingmethod = routingoperations.methodid
AND routingoperationtools.operationnumber = routingoperations.operationnumber
LEFT OUTER JOIN tools tools ON tools.toolid = routingoperationtools.toolid
LEFT OUTER JOIN emediadetails ON emediadetails.keyvalue1 = worksorders.id
AND emediadetails.keyvalue2 = routingoperations.operationnumber
AND emediadetails.emediaid = 'worksorderoperation'
I do not have too much of the test data but I know that one row is copied twice as the result of the query below even tho I used DISTINCT keyword. I know that my problem is rather specific and not general but the solution that someone will propose may help others with the similar problem.
I can't solve your problem for you without some test data, but I have some helpful hints.
In principle, you should be really careful with DISTINCT - its a great way of hiding bugs in your query. Only use DISTINCT if you are confident that the underlying data contains legitimate duplicates. If your joins are wrong, and you're getting a cartesian product, you can remove the duplicates from the results with DISTINCT - but that doesn't stop the cartesian product being generated. You'll get very poor performance, and possibly incorrect data.
Secondly, I am pretty sure that DISTINCT works properly - you are almost certainly not getting duplicates, but it may be hard to spot the difference between two rows. Leading or trailing spaces in text columns, for instance could be to blame.
Finally, to work through this problem, I'd recommend building the query up join by join, and seeing where you get the duplicate - that's the join that's to blame.
So, start with:
SELECT
traders.name AS tradername,
worksorders.id AS worksorderno,
worksorders.partid,
worksorders.quantity,
worksorders.duedate,
worksorders.traderid,
worksorders.orderid
FROM worksorders
INNER JOIN traders traders ON
worksorders.traderid = traders.id
and build up to the next join.
Are you sure the results are exact duplicates? Makes sure there isn't one column that actually has a different value.
I have the following query in HQL :
public IEnumerable<Player> PlayersNotInTeam(Team team)
{
return Session.CreateQuery("from Player p where p.Sex = :teamSex and p.Visible and p.Id not in (select pit.Player from PlayerInTeam as pit join pit.Roster as roster join roster.Team as team where team = :teamId)")
.SetParameter("teamId", team.Id)
.SetParameter("teamSex", team.Sex)
.Enumerable<Player>();
}
When I run this query with NHibernate, it will return 2 rows.
If I run the SQL script generated by NH in my database browser (SQLite Explorer):
select player0_.Id as Id26_, player0_.Sex as Sex26_, player0_.FirstName as FirstName26_, player0_.LastName as LastName26_, player0_.DefaultNumber as DefaultN5_26_, player0_.Visible as Visible26_, player0_.DefaultPosition_id as DefaultP7_26_
from Players player0_
where player0_.Sex='Male'
and player0_.Visible=1
and (player0_.Id not in
(select playerinte1_.Player_id
from "PlayerInTeam" playerinte1_
inner join "Roster" roster2_ on playerinte1_.Roster_id=roster2_.Id
inner join Teams team3_ on roster2_.Team_id=team3_.Id,
Players player4_
where playerinte1_.Player_id=player4_.Id
and team3_.Id=2));
I have 3 rows, which is what I should have.
Why are my results different?
Thanks in advance
Mike
I have noticed that sometimes the logged SQL is not exactly the same as the one being really used against the database. The last time I had this issue, it was a problem with trimming the Id value, e.g., where the generated SQL has something like and team3_.Id=2, the SQL being used was actually and team3_.Id='2 ' (or perhaps, player_0.Sex='Male '), which would always fail.
I would suggest you try this HQL:
string hql = #"from Player p where p.Sex = 'Male'
and p.Visible and p.Id not in
(select pit.Player from PlayerInTeam as pit join pit.Roster as roster join roster.Team as team where team = 2)";
return Session.CreateQuery(hql).Enumerable<Player>();
If that works, you need to check if your values have spare whitespaces in them.
I've changed my query like this:
return Session.CreateQuery("from Player p where p.Sex = :teamSex and p.Visible and not exists (from PlayerInTeam pit where pit.Player = p and pit.Roster.Team = :teamId)")
.SetParameter("teamId", team.Id)
.SetParameter("teamSex", team.Sex)
.Enumerable<Player>();
And it now works. I had the idea to use "not exists" after I changed my mappings to try to use LINQ, which gave me the hint.
If you ask why I don't keep LINQ, that's because currently I hide the relationships between my entities as private fields, to force the users of the entities to use the helper functions which associate them. But the wrong thing is that in most cases, that forbids me to use LINQ in my repositories.
But I'm wondering if this wouldn't be better to "un-hide" my relationships and expose them as public properties, but keep my helper functions. This would allow me to use LINQ in my queries.
What do you do in your apps using NH?
Do you think this would be an acceptable trade-off to maintain easy mappings and queries (with the use of LINQ), but with the cost of some potential misuses of the entities if the user doesn't use the helper functions which keep the relationships?