Year team name lastname goals teamate goals
1875 Philadelphia Athletics George Hall 12 Bill Craver 11
1875 Philadelphia Athletics Bill Craver 11 George Hall 12
I'm getting output like this which is redundant.
I only want one player name and one teammate's name
If you just need one team name or player name, then use a "group by" clause on those columns, and pick the aggregated values of the other columns.
For more details, you may copy and paste your query here and that will help us understand the problem more precisely.
Related
Here's my situation : I have a table that has large amounts of records, I need to pull out a number of these records for each name in the database, note that TOP will not work for my use case. My end user wants the report formatted in such a way that each user shows up only once, and up to 3 different dates are shown for the user.
Table format
AutoID
Enum
TNum
Date
Comments
1
25
18
2/2/22
2
25
18
1/2/21
Blah
3
18
18
1/2/21
4
18
18
1/2/20
5
25
17
1/2/22
6
25
17
1/2/20
Now the Enum and TNum fields are fk with other tables, I have created a join that pulls the correct information from the other tables. In the end my query provides this output
RecordID
Training
CompletedDate
FirstName
LastName
Location
2821
MaP
1/1/21
David
Simpson
123 Sesame St.
2822
1/2/22
Fuller
MaP
Dough
GHI
David
123 Sesame St.
2825
1/1/20
Simpson
The two "Blank fields" represent information that is pulled and may or may not be needed in some future report.
So to my question : How do I manage to get a report, with this query's pull to look like this:
Place
LastName
FirstName
Training
FirstCuttoff
Secondcutoff
ThirdCutoff
Comments
123 Sesame St.
David
Simpson
MaP
1/1/20
1/1/21
123 Sesame St.
John
Dough
MaP
1/1/22
I was originally planning on joining my query to itself using where clauses. But when I tried that it just added two extra columns of the same date. In addition it is possible that each record is not identical; locations may be different but since the report needs the most recent location and the name of the trainee. In addition, to add more complexity, there are a number of people in the company with effectively the same name as far as the database is concerned, so rejoining on the name is out. I did pull the Enum in my query, I can join on that if needed.
Is there an easier way to do this, or do I need to sort out a multiple self-joining query?
I have a project I am working on where I am going to have to do this. Some of the suggestions I received were to use a Pivot query. It wouldn't work in my case but it might for yours. Here is a good example
Pivot Columns
Name Place visited
Ash New york
Bob New york
Ash Chicago
Bob Chicago
Carl Chicago
Carl Detroit
Dan Detroit
Above is the sample table. The output should be two names who visited place together. I.e. the output should be Ash and Bob since the places visited by Ash also visited by Bob.
Output:
Name1 Name2
Ash Bob
What is a query for this using MySQL or even relational algebra?
The simplest method is to use group_concat(). Assuming no duplicates,
select places, group_concat(names) as names
from (select name, group_concat(place order by place) as places
from t
group by name
) t
group by places
having count(*) > 1;
This will return all the names with exactly the same places on a single row. The names will be in a comma-delimited list.
This question already has an answer here:
How to output table results by using cfoutput group by date?
(1 answer)
Closed 7 years ago.
I'm working on outputting values from data base in the table. My table has 5 columns: Date, FirstName, LastName, City, State. Here is example of my data base table:
DateMeeting FirstName LastName City State
2015-12-11 Mike Johns Dallas TX
2015-12-11 John Cook Dallas TX
2015-12-11 Nick Roberts Dallas TX
2015-12-11 Oliver Ryan New York NY
2015-12-11 Michael Best New York NY
2015-12-11 David Holmes New York NY
So I want to have output table that will display just one date for multiple records. I tried to use DISTINCT on the date and that works fine but if I include my WHERE clause for City and State my query breaks. Also I tried to use GROUP BY but same problem, I can get Date values only once as long as I do not include other columns. In this case I need all columns but my Date value only once. Here is my query that I use:
Select Distinct(DateMeeting),FirstName, LastName, City, State
From Customers
Where City = 'Dallas'
and State = 'TX'
This query does not work with all columns that I have in my select, only if I run DISTINCT(DateMeeting). I would like to output my values in the table to look like this:
Date First Name Last Name City State
Mike Johns Dallas TX
John Cook Dallas TX
Nick Roberts Dallas TX
2015-12-11 Oliver Ryan New York NY
Michael Best New York NY
David Holmes New York NY
If anyone knows how this can be done please let me know. Thank you.
Each layer in the technology stack has its strengths and weaknesses.
As for mysql, do not turn it into a report engine as described with blank date columns except for one per date somewhere in the middle of a date chunk as shown. Subsequent dates as ordered will get muddled and confused.
True, one could use slightly interesting mysql variables and dump it just on the first row of a chunk. But for what.
Play to mysql's strengths, return all the data. And have the front-end (coldfusion or whatever), deal with the reporting features you desire for the output.
Book Name Author Name No. of Copies Entry Date
Web Development Er. Gurbax Singh 7 2015-10-07
PHP Mr. Yash Arora 5 2015-10-06
DBMS Mr. Subhash Singla 2 2015-10-30
Data Structure Mr. Balwinder Singh 6 2015-11-14
Multimedia Dr. Latila Bhutani 3 2015-11-23
Graphics Designing Er. Gurpreet Kaur 6 2015-11-23
Note: I want sum of no. of copies
use SUM
SELECT SUM(no_of_copies) AS totalBooks FROM tablename
or Group by sum
SELECT SUM(no_of_copies) AS totalBooks FROM tablename group by BookName
Sorry if the title is not clear. I am a bit confused about how to plan my database schema as given my database design skill level the requirement falls under kind of advanced :) I could really use some help here. Anyway, here it goes ...
I need to track match details for teams. For the sake of simplicity, lets say I need to track the match date, result and the teams that played the match. Now, how do I design my tables so I can make sure all relevant data is returned without having to keep multiple records of the same match. I am not sure if I am explaining clearly, so here's an example below.
match_id team1 team2 result
________ ________ ________ ________
1 Arsenal Chelsea 5-3
2 Manchester Utd Arsenal 1-0
3 Liverpool Newcastle 2-0
4 Arsenal Everton 1-0
From this data, if I search for match_ids for matches played by Arsenal, I should get the below results,
1,2,4.
Now, in the basic designs which I know of, I would normally search for matched in team name for the team name supplied and return the result. But here the team name can be in two different columns and both can be relevant. So, is it something I need to decide on the design level or something that can be done with some sort of query.
(Note: Storing teams as home/away is not an option for my requirement).
You can just query both columns, it's not a problem:
select match_id
from matches
where team1 = 'Arsenal' or team2 = 'Arsenal';
(You could also normalize this schema by placing teams in their separate table and leaving only their ids in the matches table, but that doesn't change much, you still have to query both columns. Read about database normalization, any SQL book covers this).
If there are always two teams per match, then I think you did a good job here, and when querying for a particular team, you'll want to search for one column OR the other (SELECT match_id FROM matches WHERE team1 = "?" OR team2 = "?").
One note though: I would definitely split up the score into two columns:
match_id team1 team2 score1 score2
________ ______________ _________ ______ ______
1 Arsenal Chelsea 5 3
2 Manchester Utd Arsenal 1 0
3 Liverpool Newcastle 2 0
4 Arsenal Everton 1 0
This way you'll be able to query on scores later on, if you need it. (e.g. Big wins = SELECT match_id FROM matches WHERE ABS(score1 - score2) > 3;)
The other option you have should be more scalable if there exists a possibility of having more than two teams per match. If this is the case, then you'd likely want to remove the uniqueness constraint on match_id and cut out the team/score columns from 2 to 1:
match_id team score
________ ________ ____
1 Arsenal 5
1 Chelsea 3
2 Manchester Utd 1
2 Arsenal 0
3 Liverpool 2
3 Newcastle 0
4 Arsenal 1
4 Everton 1
And of course, you're definitely going to want to take Sergio's advice in putting all this stuff into separate tables. "Teams" are likely going to have different attributes (hometown, coach name, etc.), and you're not going to want to duplicate that data.
This will give you the results you want but there may be a better design too.
Select *
from table
where (team1 = 'ARSENAL' or Team2 = 'ARSENAL')
You may want to Separate out scores such as Team1Score Team2Score otherwise you can't easily do math with them.
for star I would not store the time name, I think its better if you store the times in other table and linq then thru an id.
And then you could create a table with columns id, match id and team id, and just search for the team id in that table!
you can used this query and its no problem for your program:
select YOUR_ID_FIELDS
from YOUR_TABLE_NAME
where YOUR_FIELD_NAME(team1) = 'Arsenal' or YOUR_FIELD_NAME(team2) = 'Arsenal';
and for exmale (Chelsea)
select YOUR_ID_FIELDS
from YOUR_TABLE_NAME
where YOUR_FIELD_NAME(team1) = 'Chelsea' or YOUR_FIELD_NAME(team2) = 'Chelsea';