PostgreSQL how to add aggregated column to existing query - mysql

I have project to analyze premier league stats 2011/12 and I wanna operate on one column (scored goals) when playerd from start(1) or substituted(0) and I wanna show name,surname and sum of scored goal when player started game and substituted. which looks like this only for score at home:
and I wanna make this looks like this
I know that this subquery is wrong because it summing all goals not by the player.
How to make it looks separate like for van persie 28 scored from start(1) and from bench (0) supposed to be 2?
erd diagram if you wanna see:
https://postimg.org/image/u46b6lve3/

Your sub query counts all the goals because you are not passing player id to it, try changing the query to the following:
select player_id as pid, //other columns
select sum(goals) from projekt.statictics where starts = 0 and player_id = pid) as wyjazd
from //conditions
You may need to change the column names based on what they are named in the tables.

Related

How to create this dynamic PIVOT view where the price of 3 fruits are not changing simultaneously?

The Initial Data View, we have
Lets consider this table as Table A.
Here we can see that there are 3 markets: A,B,C and there are 3 fruits: Apple, Banana, Strawberry.
There is Start Date and End Date for each of the fruits of each market. These dates imply that the price of the fruit is applicable b/w that interval of dates. If the End Date is empty that means the rate is still applicable.
Now from this table, we want a transposed view of the table. And the final output we want is:
The View, we want
Lets consider this table as Table B.
This looks like a simple PIVOT function in SQL to transpose the rates and we tried that. But the result we are getting is not expected. The output is coming out to be:
The Output, we are getting
Lets consider this table as Table C.
The problem is that as in markets A and B, the rates of the 3 fruits are not simultaneously changing, the PIVOT function is not giving expected results.
We have tried the simple pivot function on the Table A:
The code we are using for the PIVOT-
PIVOT(MAX(PRICE/kg)) FOR FRUIT IN
('Apple_Price', 'Banana_Price', 'Strawberry_Price')
AS (MARKET, START_DATE, END_DATE, Apple_Price, Banana_Price, Strawberry_Price)
We have also tried another method where we tried to join 3 times separately Table A. But it is also not working.

MySQL Query - Lowest Values with Multiple Tables / Joins

i am requesting some help for a query to be used on a custom golf website.
what i need is to find the lowest score per player per course. my club has 3 nine hole loops, 27 holes in total, but i want to find the lowest per 9 holes (i.e. course as i am describing it).
i have the following database structure (note, i haven’t put in all rows, only those that are pertinent to the query i am stuggling with).
Golf DB ERP Diagram
a query to get the full set of data would be (note some field names are different - the diagram was trying to better descriptive…):
select * from round r, round_hole rh, player p, course_nine c, course_hole ch
where r.r_id = rh.rh_rid
and p.id = r.r_pid
and c.cn_nine = r.r_nine
and ch.ch_nine = c.cn_nine
and rh.rh_hid = ch.ch_no
a snapshot of the results are:
Full query ouput
however, i then need to filter it as above, into "per player, per course”
i am presuming this is some subquery, join, temp table or “in” type statement, but struggling, particularly as it spans multiple tables.
any help is appreciated
This can be accomplished using some simple aggregation. As long as you are able to properly join all of your tables, you can do this:
SELECT player, course, MIN(score) AS lowestScore
FROM myTables
GROUP BY player, course;

count number of repeating entries

I am fairly new to Databases and I am just beginning to understand the DML/queries, I have two tables, one named customer this contain customer data and one named requested_games, this contains games requested by the customers, I would like to write a query that will return the customers that have requested more than two games, so far when I run the query, I don't get the desired result, not sure if I'm doing it right.
Can anyone assist with this thanks,
Below is a snippet of the query
select customers.customer_name, wants_list.requested_game, wants_list.wantslists_id,count(wants_list.customers_ID)
from customers, wants_list
where customers.customers_ID = wants_list.customers_id
and wants_list.wantslists_id = wants_list.wantslists_id
and wants_list.requested_game > '2';
just include a HAVING clause
GROUP BY customers_ID
HAVING COUNT(*) > 2
depending on how you have your data setup you may need to do
HAVING COUNT(wants_list.requested_game) > 2
This is how I like to describe how a query works maybe itll help you visualize how the query executes :)
SELECT is making an order at a restaurant....
FROM is the menu you want to order from....
JOIN is what sections of the menu you want to include
WHERE is any customization you want to make to your order (aka no mushrooms)....
GROUP BY (and anything after) is after the order has been completed and is at your table...
GROUP BY tells your server to bring your types of food together in groups
ORDER BY is saying what dishes you want first (aka i want my entree then dessert then appetizer ).
HAVING can be used to pick out any mushrooms that were accidentally left on the plate....
etc..
I would like to write a query that will return the customers that
have requested more than two games
For this to happen you need to do the following
First you need to use GROUP BY to group the games based on customers (customers_id)
Then you need to use HAVING clause to get customers who requested more than two games
Then make this a SUBQUERY if you need more information on the customer like name
Finally you use a JOIN between customers and the sub query (temp) to display more information on the customer
Like the following query
SELECT customers.customer_id, customers.customer_name, game_count
FROM (SELECT customer_id, count(wantslists_id) AS game_count
FROM wants_list
GROUP BY customer_id
HAVING count(requested_game) > '2') temp
JOIN customers ON customers.customer_id = temp.customer_id

MySQL Union (or similar) query

I have some booking data from a pair of views in MySQL. They match columns perfectly, and the main difference is a booking code that is placed in one of these rows.
The context is as follows: this is for calculating numbers for a sports camp. People are booked in, but can do extra activities.
View 1: All specialist bookings (say: a football class).
View 2: A general group.
Due to the old software, the booking process results in many people booking for the general group and then are upgraded to the old class. This is further complicated by some things elsewhere in the business.
To be clear - View 1 actually contains some (but are not exclusively all) people from within View 2. There's an intersection of the two groups. Obviously people can't be in two groups at once (there's only one of them!).
Finding all people who are in View 2 is of course easy... as is View 1. BUT, I need to produce a report which is basically:
"View 1" overwriting "View 2"... or put another way:
"View 1" [sort of] UNION "View 2"
However: I'm not sure the best way of doing this as there are added complications:
Each row is as approximately (with other stuff omitted) as follows:
User ID Timeslot Activity
1 A Football
1 A General
2 A General
3 A Football
As you can see, these rows all concern timeslot A:
- User 2 does general activities.
- User 3 does football.
- User 1 does football AND general.
AS these items are non unique, the above is a UNION (distinct), as there are no truly distinct rows.
The output I need is as follows:
User ID Timeslot Activity
1 A Football
2 A General
3 A Football
Here, Football has taken "precedence" over "general", and thus I get the picture of where people are at any time.
This UNION has a distinct clause on a number of fields, but ignores others.
So: does anyone know how to do what amounts to:
"add two tables together and overwrite one of them if it's the same timeslot"
Or something like a:
"selective distinct on UNION DISTINCT".
Cheers
Rick
Try this:
SELECT *
FROM
(SELECT *,
IF(Activity='General',1,0) AS order_column
FROM `Table1`
ORDER BY order_column) AS tmp
GROUP BY UserId
This will add an order_column to your original table that as value 1 if the Activity value is general; Doing this we can select this temporary table ordering by this column (ascending order) and all record with general activity comes after all others. After that we can simply select the result of this temporary table grouping by user id. The group by clouse without any aggregate function takes the first record that match.
EDIT:
If you don't to use group by without aggregate function this is an 'ugly' alternative:
SELECT UserId,
Timeslot,
SUBSTRING(MAX(CASE Activity WHEN "General" THEN "00General" WHEN "Football" THEN "01Football" ELSE Activity END) , 3)
FROM `Table1`
GROUP BY UserId,
Timeslot LIMIT 0 ,
30
Here we need to define each possible value for Activity.

Soccer SQL Query Home- and Roadteam Issue

In a soccer environment I want to display the current standings. Meaning: points and goals per team. The relevant tables look similar to the following (simplified).
Match Table
uid (PK) hometeamid roadteamid
------------------------------------------------------------------
Result Table
uid (PK) hometeamscore roadteamscore resulttype (45min, 90min, ..)
-------------------------------------------------------------------
Team Table
uid (PK) name shortname icon
------------------------------------------------------------------
Now I don't get my head around it, how to write the standings in one query. What I managed was to write a query, which returns the "homegames"-standings only. I guess that's the easy part. Anyway here is how it looks:
SELECT ht.name,
Count(*) As matches,
SUM(res.hometeamscore) AS goals,
SUM(res.roadteamscore) AS opponentgoals,
SUM(res.hometeamscore - res.roadteamscore) AS goalDifference,
SUM(res.hometeamscore > res.roadteamscore) * 3 + SUM(res.hometeamscore = res.roadteamscore) As Points
FROM league_league l
JOIN league_gameday gd
ON gd.leagueid = l.uid
JOIN league_match m
ON m.gamedayid = gd.uid
JOIN league_result res
ON res.matchid = m.uid
AND res.resulttype = 2
JOIN league_team ht
ON m.hometeamid = ht.uid
Where l.uid = 1
Group By ht.uid
Order By points DESC, goalDifference DESC
Any idea how to modify this, that it will return home- and roadgames would be big time appreciated.
Many thanks,
Robin
Create views. If your data does not change often and you need performance, create one or more pre-computed tables.
Views in MySQL are juste pseudo-tables that are dynamically computed from a SELECT query. Using the SQL in your question, you can create a view of the teams results at home: CREATE VIEW homegames AS SELECT ...
Then do the same for road games. Then it will be easy to synthesize both views in a third one (you just need to sum up the columns).
Views have at least one flaw: they are slow. A view built on views is like using complex subqueries, and MySQL is quite bad at this. I don't think it's a problem for you as you're probably dealing with hundreds of games at most. But if you find these views to be too slow to query, and provided you don't use any kind of cache that could mitigate this, then use simple tables instead of views. Of course, you'll need to keep them in sync. You can TRUNCATE and INSERT INTO homegames SELECT ... each time you have a new game, or you can be smarter and just UPDATE the tables. Both are right, depending on your needs.
Could you not abstract this out into a stored procedure or stored function to call rather than constructing such a big-ass complicated query?