I've got a table with 3 separate scores in 3 separate fields:
User / Score 1 / Score 2 / Score 3
Person 1: 10 21 7
Person 2: 17 4 20
Person 3: 1 5 22
Is there a mysql command that will effectively sort each person out by the highest score from the 3 fields.
So here I need it to return:
Person 3: 1 5 22
Person 1: 10 21 8
Person 2: 17 4 20
The only way I can think of doing it would be to put them in an array, check each number for each person against each other to find the highest, then sort them into a different array.
This seems very long-winded and labour intensive though.
Add order by greatest(score1,score2,score3) desc
Manual for GREATEST()
Related
i am having a problem, i am not that good in logic, so i am trying to do this by just using queries only,
i have a list of data, where i need to get their ranking, but the problem is, i need to get the first two upper to me and the last two who is lower to me.
for example
id| name | score
1 bob 20
2 anna 10
3 jose 30
4 boni 30
5 lea 100
6 leo 10
7 qwertina 90
8 josh 50
9 king 40
10 queen 10
imagine that my id value as a user is 7
so if i log in and my id is 7
i need to get the output of
id| name | score
5 lea 100
6 leo 10
7 qwertina 90
8 josh 50
9 king 40
is this possible in mysql query? any help would be really appreciated, i am really stuck with this problem.
You seem to base your logic on id's which is quite strange but here we are :
SELECT id, name, score
FROM yourTable
WHERE id BETWEEN yourId-2 AND yourId+2
Not sure of a MySQL only solution, but in pseudo php code
Grab records ordered by score
set a counter at 0
for loop starting 0, <= count of results
if the id your id?
if the loop index < 3 ? // there aren't two people ahead of you
return rows 0 to 4
elseif the loop index > count -3 ? // you are one of the last
return rows count -4 to count
else
return rows index -2 to index + 2 // you have 2 above and below you
Try that and if you get stuck post your PHP
Need some help in ranking poll options, tried doing by multidimensional arrays but nothing worked.
My data structure is as per below:
**Table** Poll
**Id** **Question** **op1** p1 **op2** p2 **op3** p3 **op4** p4 **op5** p5
1 q1 ? Excellent 5 Better 4 Good 3 Ok 2 Not OK 1
2 q2 ? Sure 5 Perfect 4 Fine 3 Never 2 No 1
**Table** Answer
**id** **poll_id** **users_id** **answer** **resultOrder**
---------------------------------------------------------------
1 1 1 Excellent 1
2 1 1 Better 2
3 1 1 Ok 3
4 1 1 Good 4
5 1 1 Not Ok 5
6 1 2 Excellent 1
7 1 2 Ok 2
8 1 2 Better 3
9 1 2 Not Ok 4
10 1 2 Good 5
Each user will submit five options priorities them as per his suggestion
Option will get ranking as per counts
e.g Excellent selected for 2 times for first preference it will get 100 points and others will get 80,60,40,20 points based on their counts for all priorities.
if count ties matches points will be given on p1, p2 column in table poll
**For Example if my group by [answer] look like below 5 people voted Excellent as first preference, 4 people voted better as second preference and so on till Not Ok preferred by 1 person for fifth preference **
Answer count(answer) it should set point like this
Excellent 5 100
Better 4 80
Good 3 60
Ok 2 40
Not Ok 1 20
Hope this is possible. I tried it many ways, but no luck.
With these tables:
workshops
WorkshopID | WorkshopName | WorkshopLimit
1 Workshop A 10
2 Workshop B 20
3 Workshop C 30
4 Workshop D 40
5 Workshop E 50
workshop_participants
ParticipantID | RegistrantID | WorkshopID
1 1 1
2 1 2
3 2 3
4 3 2
5 3 5
6 4 1
7 4 4
8 5 4
Is it faster to just subtract and update the number of WorkshopLimit for each registration, or count the total number of participants of a certain workshop then subtract it to the WorkshopLimit (without updating WorkshopLimit) ?
An example of usage for this is when I will check the remaining slot of a certain workshop.
It is faster to run a simple select statement like SELECT WorkshopLimit FROM workshops WHERE id = 42 to read a simple value from a datarow to check the remaining open seats in a workshop than to use a more complex query involving an aggregate function like COUNT(...) to calculate the remaining open seats on demand all the time.
However, it is most likely not speed-wise relevant at all if you update the remaining open seats value in the workshops table at each registration OR if you calculate the remaining seats on the fly when needed. They are both too fast to be relevant for your decision to use one approach or the other.
TL;DR = It doesn't matter.
It depends on how strict of your WorkshopLimit. If over-registration is prohibited, updating WorkshopLimit is an easy way to guard the rule. Make registration and updating WorkshopLimit in a transaction, if WorkshopLimit is less than 0, rollback the transaction and cancel the registration.
If over-registration is allowed, both solution is acceptable. As if you don't have huge data volume, performance difference should be minor.
I've done some digging and I can't find an effective way to prevent duplicate entries based on my needs. I need columns 2 (proj_id) and column 4 (dept_id) never to be the same, as each dept would only work on a project once. So, rows 1 and 4, 6 and 7, and 14 and 15 shouldn't be allowed. I'll keep digging as well.
summary_id proj_id hours_id dept_id date_entered
1 8 3 6 9/9/2012
2 2 2 6 9/9/2012
3 1 6 19 9/9/2012
4 8 3 6 9/9/2012
5 2 5 17 9/9/2012
6 7 2 5 9/9/2012
7 7 2 5 9/9/2012
8 2 5 17 9/9/2012
9 7 4 17 10/10/2012
10 3 6 1 10/10/2012
11 5 1 15 10/10/2012
12 4 4 3 10/10/2012
13 3 5 1 10/10/2012
14 8 2 13 10/10/2012
15 8 2 13 10/10/2012
Before applying unique combine key to your table, you have to remove duplicate records first then apply the following sql command:
ALTER TABLE your_table_name ADD UNIQUE (proj_id, dept_id);
Define an unique key on both columns
ALTER TABLE `your_table` ADD UNIQUE (`proj_id`, `dept_id`);
Looks like you are new to php and mysql. So here's the easiest way to do it.
Log on to PHPMyAdmin
Select your DB and your table.
View the Structure of it (clicking the button on top of the screen).
Check the two fields (proj_id and dept_id) using the check box on the left.
At the bottom of the table you should find the the words "With selected" and in front of it some actions. Select the option to make "Primary".
Of course, if you have duplicate entries first delete them.
I have a problem trying to apply rules about direct matches in a football[soccer] app. I have read this tread and it was very heplful on creating the standing positions table by the points criteria, difference and scored goals.
But i would like to know if is possible to order the teams position by direct matches:
look this positions table:
Pos Team Pld W D L F A GD Pts
1 FC Barcelona 5 2 3 0 8 5 3 9
2 **Inter Milan** 6 2 2 2 11 10 1 8
3 *Real Madrid* 6 2 2 2 8 8 0 8
4 AC Milan 5 0 3 2 8 12 -4 3
As you may see Inter Milan and Real Madrid are tied by points, and the Inter is heading real madrid because its goal difference. The result that i want to get is this :
Pos Team Pld W D L F A GD Pts
1 FC Barcelona 5 2 3 0 8 5 3 9
2 **Real Madrid** 6 2 2 2 8 8 0 8
3 *Inter Milan* 6 2 2 2 11 10 1 8
4 AC Milan 5 0 3 2 8 12 -4 3
Notice that in this time the real madrid is in front the inter milan because it won the two direct matches between them.
i have a table for teams and other for the results.
I would like to achive this using a query in mysql if is possible. Or maybe it would be better if i do this ordering on the server side (PHP).
Thanks any help would be appreciated.
It is impossible to efficiently do what you request in a single query that would return the results you ask for and sort the ties in points with that criteria.
The reasoning is simple: lets assume that you could get a column in your query that would provide or help with the kind of sorting you want. That is to say, it would order teams that are tied in points according to which one has more victories over the others (as this is very likely to happen to more than 2 teams). To make that calculation by hand you would need a double-entry table that shows the amount of matches won between those teams as follows:
| TeamA | TeamB | TeamC
------------------------------
TeamA | 0 | XAB | XAC
TeamB | XBA | 0 | XBC
TeamC | XCA | XCB | 0
So you would just add up each column row and sorting in descending order would provide you the needed data.
The problem is that you don't know which teams are tied before you actually get the data. So creating that column for the general case would mean you need to create the whole table of every team against every team (which is no small task); and then you need to add the logic to the query to only add up the columns of a team against those that are tied with it in points... for which you need the original result set (that you should be creating with the same query anyhow).
It may be possible to get that information in a single query, but it will surely be way too heavy on the DB. You're better off adding that logic in code afterwards getting the data you know you will need (getting the amount of games won by TeamA against TeamB or TeamC is not too complicated). You would still need to be careful about how you build that query and how many you run; after all, during the first few games of a league you will have lots of teams tied up against each other so getting the data will effectively be the same as building the whole double-entry table I used as an example before for all teams against all teams.
create temporary in a stored procedure and call to procedure...
create temporary table tab1 (position int not null auto_increment ,
team_name varchar(200),
points int,
goal_pt int,
primary key(position));
insert into tab1(team_name,
points,
goal_pt)
select team_name,
points,
goal_pt
from team
order by points desc,
goal_pt desc ;