How to specify WHERE in a JOIN statement? - php

This is my first attempt at a JOIN MySQL statement...
I have 2 tables..games and games_ratings
both tables have an id column. the id represents the id of the game. and i only want to get the average of the ints in the rating column where the id in games_ratings is equal to the id from the games table.
SELECT a.id, a.name, AVG(b.rating) AS average FROM games a LEFT JOIN games_ratings b GROUP BY a.id ORDER BY average DESC LIMIT 50;
any ideas?

Try this:
SELECT a.id, a.name, AVG(b.rating) AS average
FROM games a
LEFT JOIN games_ratings b
ON a.id = b.id # <-- You need this line I believe
GROUP BY a.id
ORDER BY average DESC LIMIT 50;
Edit: This is a bit hard without your complete schema, but you can try something like this.
SELECT a.id, a.name, AVG(b.rating) AS average, COUNT( b.id) as votes
FROM games a
LEFT JOIN games_ratings b
ON a.id = b.id
GROUP BY a.id
ORDER BY votes DESC, average DESC LIMIT 50; # <-- You may need to modify this line

Don't forget the WHERE clause he asked for:
where the id in games_ratings is equal to the id from the games table
> SELECT a.id, a.name, AVG(b.rating) AS average
> FROM games a
> LEFT JOIN games_ratings b
> ON a.id = b.id # <-- You need this line I believe
> **WHERE a.id = b.id**
> GROUP BY a.id
> ORDER BY average DESC LIMIT 50;

Related

LIMIT LEFT join to last updated row from multiple rows

This is my code i am trying to left join the latest team data, not every piece of data. i have tried just using limit 1 but doesnt return anything
ORDER BY updated DESC LIMIT 1
this doesnt work
Any ideas?
$sql = "SELECT
events.id, events.time,events.status, events.home_team,events.away_team,events.league,
ht.id as home_id,ht.name as home_name,at.name as away_name,
statistics.home_goals,statistics.away_goals,statistics.time as game_time,
leagues.id as league_id,leagues.name as league_name,leagues.type as league_type,
country.name as country_name,country.logo,
hts.home_scored, ats.away_scored,
hts.home_conceeded,ats.away_conceeded,
hts.home_win,ats.away_win,
hts.home_15,ats.away_15,
hts.home_25,ats.away_25,
hts.home_btts, ats.away_btts,
hts.home_fts, ats.away_fts,
hts.home_cs, ats.away_cs,
hts.home_corners_for, ats.away_corners_for,
hts.home_corners_against, ats.away_corners_against,
hts.home_cards, ats.away_cards
FROM events
LEFT JOIN teams ht
ON ht.id = events.home_team
LEFT JOIN teams at
ON at.id = events.away_team
LEFT JOIN leagues
ON leagues.id = events.league
LEFT JOIN country
ON country.id=leagues.country
LEFT JOIN ( SELECT team,home_scored,home_conceeded,home_win,home_15,home_25,home_btts,home_fts,home_cs,home_corners_for,home_corners_against,home_cards FROM team_quick_stats ORDER BY updated DESC) hts
ON ht.id=hts.team
LEFT JOIN ( SELECT team,away_scored,away_conceeded,away_win,away_15,away_25,away_btts,away_fts,away_cs,away_corners_for,away_corners_against,away_cards FROM team_quick_stats ORDER BY updated DESC) ats
ON at.id=ats.team
LEFT JOIN statistics
ON statistics.event_id=events.id
WHERE (events.time BETWEEN $start AND $end) ORDER BY country.list_order, leagues.country ASC , leagues.id ASC, events.time ASC, home_name ASC";
Here's one way. Replace LEFT JOIN (SELECT team... etc....) ats with...
LEFT
JOIN
( SELECT x.team
, x.etc...
FROM team_quick_stats x
JOIN
( SELECT team
, MAX(updated) updated
FROM team_quick_stats
GROUP
BY team
) y
ON y.team = x.team
AND y.updated = x.updated
) ats...

How to show name of course in INNER JOIN?

I have two tables: users and courses. Inside users table i have filed course where i have course id. Inside courses table i have just ID and NAME.
I need to get popular course. I do request:
SELECT u.course, COUNT(*) as freq FROM users u INNER JOIN courses c ON u.course = c.id GROUP BY u.course
As a result: id => freq. But i need to replace ID to NAME of course. How?
Thanks.
You don't say what database you use, but I would assume you can use CTEs since most modern databases do. Your query can be written as:
with x as (
select course, count(*) as freq from users group by course
),
y as (
select max(freq) as max_freq from x
)
select c.name, x.freq
from x
join y on x.freq = y.max_freq
join courses c on c.id = x.course
This query has the [desirable?] side effect that it shows more than one course, if there are more than one tied in first place.
Add c.name to both the SELECT clause and the GROUP BY clause.
SELECT u.course, c.name, COUNT(*) as freq
FROM users u
INNER JOIN courses c
ON u.course = c.id
GROUP BY u.course, c.name;
Demo: https://dbfiddle.uk/?rdbms=mariadb_10.3&fiddle=02a41e0f1e6407e516e91c49b4bdc1d2
SELECT u.course, COUNT(*) as freq, c.name FROM users u INNER JOIN courses c ON u.course = c.id GROUP BY u.course
If your DBMS supports row_number this will be suitable:
select t.id, c.name, t.cnt
from course c
join (
select c.id, count(1) cnt, ROW_NUMBER() over(order by count(1) desc) rn
from users u
join course c on c.id = u.course
group by id
)t on t.id = c.id and t.rn = 1

Multiple Counts in MYSQL PHP Query

I'm trying to create a leaderboard but i'm not sure how to do the mysql query.
I would like to count all the levels from a player in the skills table and get the total Level and count all the experience from a player in the experience table and get the Total Exp along with displaying the persons name from the users column.
There is 3 tables factions_mcmmo_users, factions_mcmmo_experience, factions_mcmmo_skills.
This is what i have so far but it doesn't work:
$sql = ("SELECT a.id,
(SELECT COUNT(*) FROM factions_mcmmo_experience WHERE user_id = a.id) as TotalXP,
(SELECT COUNT(*) FROM factions_mcmmo_skills WHERE user_id = a.id) as TotalLevel
FROM (SELECT DISTINCT id FROM factions_mcmmo_users) a LIMIT 10;");
Any help would be very appreciated
EDIT: I have it working now but i'm unsure if its the most efficient way to do things so if anyone could help me out if theres a better way, it would mean a lot.
I would also like to know if it's possible to display the total exp and level with commas if the number is in the thousands for example: total level 5,882 and total xp 582,882
EDIT 2:
I have figured out how to format the numbers but still don't know if my code is efficient
$sql = ("SELECT id, user,
(SELECT FORMAT(Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy),0) FROM factions_mcmmo_skills b WHERE b.user_id = a.id) as TotalLevel,
(SELECT FORMAT(Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy),0) FROM factions_mcmmo_experience c WHERE c.user_id = a.id) as TotalXP
FROM (SELECT id, user FROM factions_mcmmo_users) a group by id ORDER BY TotalLevel DESC, TotalXP DESC LIMIT 10;");
EDIT 3
Updated code from scaisEdge but was displaying everyones level as 1 and XP as 1, so i changed count(*) changed to sum, added an order By TotalLevel in Descending order and that seems to have worked but i can't get it to display the persons name (user column) in the user table? not sure if i was supposed to change to sum because it didn't work the other way.
$sql = ("SELECT a.id, b.TotalXP, c.TotalLevel
FROM (SELECT DISTINCT id FROM factions_mcmmo_users) a
INNER JOIN (
SELECT user_id, Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy) as TotalXP
FROM factions_mcmmo_experience
GROUP By user_id
) b on b.user_id = a.id
INNER JOIN (
SELECT user_id, Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy) as TotalLevel
FROM factions_mcmmo_skills
GROUP by user_id
) c on c.user_id = a.id
ORDER BY TotalLevel DESC
LIMIT 10;");
EDIT 4
Everything working but when i try to format the totals using "FORMAT(Sum(Columns), 0) on the inner joins, the EXP Total appears to work but the main Total Level is not displaying results that are over 1,000 and it breaks the leaderboard positioning, it should be sorting them on total level but it appears to be random, when u remove the format,0 it goes back to working
I would like it to display commas if the number number is the thousands for example: Total Level: 5,532 and Total EXP 5882,882
See live demo: http://mcbuffalo.com/playground/leaderboards/server/factions-mcmmo.php
Updated Code trying to use Format:
$sql = ("SELECT a.id, a.user, b.TotalXP, c.TotalLevel
FROM (SELECT id, user FROM factions_mcmmo_users) a
INNER JOIN (
SELECT user_id, FORMAT(Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy), 0) as TotalXP
FROM factions_mcmmo_experience
GROUP By user_id
) b on b.user_id = a.id
INNER JOIN (
SELECT user_id, FORMAT(Sum(taming)+Sum(mining)+Sum(woodcutting)+Sum(repair)+Sum(unarmed)+Sum(herbalism)+Sum(excavation)+Sum(archery)+Sum(swords)+Sum(axes)+Sum(acrobatics)+Sum(fishing)+Sum(alchemy), 0) as TotalLevel
FROM factions_mcmmo_skills
GROUP by user_id
) c on c.user_id = a.id
ORDER BY TotalLevel DESC;");
EDIT 5
Changed number with PHP, everything works
Original Images
you could use an couple of inner join
$sql = ("SELECT a.id, a.name, b.TotalXP, c.TotalLevel
FROM (SELECT DISTINCT id, name FROM factions_mcmmo_users) a
INNER JOIN (
SELECT user_id, COUNT(*) as TotalXP
FROM factions_mcmmo_experience
GROUP By user_id
) b on b.user_id = a.id
INNER JOIN (
SELECT user_id, COUNT(*) as TotalLevel
FROM factions_mcmmo_skills
GROUP by user_id
) c on c.user_id = a.id
LIMIT 10

LEFT JOIN Query With Condition

I have a query that LEFT JOINS another table to group rows. I am trying to only select records from the first table "googleimage" where the user_id is a certain number. (user_id is a column in "googleimage" table.
SELECT g.*
FROM googleimage g
LEFT JOIN (SELECT image_id, COUNT(*) AS cnt
FROM googleimagefound WHERE status = 0
GROUP BY image_id) gf ON gf.image_id = g.id
ORDER BY COALESCE(cnt, 0) DESC");
I have tried adding a new ON statement beiside the
gf ON gf.image_id = g.id
I have also tried changing
SELECT g.*
FROM googleimage g
to
SELECT g.*
FROM googleimage WHERE user_id = 1 g
but none of them seem to work, any help will be appriciated
Try changing you query a bit like below
SELECT g.*
FROM googleimage g
LEFT JOIN (SELECT image_id, COUNT(*) AS cnt
FROM googleimagefound WHERE status = 0
GROUP BY image_id) gf ON gf.image_id = g.id
WHERE g.user_id = 1 <-- add this condition
ORDER BY COALESCE(gf.cnt, 0) DESC;

Issue with group by and order by clause with inner join

I have two tables namely locations and pilots. I have been trying to fetch data based on location_id i.e selecting pilots who are flying in a particular location_id order by date(date of schedule).
I am using group by as i need only distinct pilots to be displayed.
select B.*,
A.rather_to_be_flying_now,
A.here_now,
A.flying,
A.when,
A.my_favorite,
A.start,
A.end,
A.Locationid
from locations A
inner join pilots B
on A.Pilotid=B.pilot_id
where A.VenueID='$venueid'
and (A.flying='1' or A.here_now='1')
group by A.Pilotid
ORDER BY A.start
The query works good if i wont include a group by clause. It returns the following result
with out group by clause
with group by clause
But the above table shows wrong order, as the output must return start time as 2013-01-24 02:00:00 for pilotid 1 (Chronological order).
You can use MIN()
select B.*,
A.rather_to_be_flying_now,
A.here_now,
A.flying,
A.when,
A.my_favorite,
MIN(A.start) as start,
A.end,
A.Locationid
from locations A
inner join pilots B
on A.Pilotid=B.pilot_id
where A.VenueID='$venueid'
and (A.flying='1' or A.here_now='1')
group by A.Pilotid
ORDER BY A.start
Try this instead:
SELECT
B.*,
A.rather_to_be_flying_now,
A.here_now,
A.flying,
A.when,
A.my_favorite,
A.start,
A.end,
A.Locationid
FROM locations A
INNER JOIN
(
SELECT pilotid, MIN(start) MinStart
FROM locations
GROUP BY pilotid
) a2 ON A.pilotId = a2.pilotId
AND a.start = a2.minStart
INNER JOIN pilots B on A.Pilotid = B.pilot_id
WHERE A.VenueID = '$venueid'
AND (A.flying='1' OR A.here_now='1');
ORDER BY A.start ;
This will give you only those pilots with the minimum start date.
Try this query -
SELECT
p.pilit_id, l.location_id, l.start
FROM pilots p
JOIN (SELECT l1.*
FROM locations l1
JOIN (SELECT location_id, MIN(start) start
FROM locations
GROUP BY locations) l2
ON l1.id = l2.id AND l1.start = l2.start
) l
ON l.pilot_id = p.pilot_id
GROUP BY p.pilot_id
Add your WHERE condition.

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