I have a table of player performance:
CREATE TABLE TopTen (
id INT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
home INT UNSIGNED NOT NULL,
`datetime`DATETIME NOT NULL,
player VARCHAR(6) NOT NULL,
resource INT NOT NULL
);
What query will return the rows for each distinct home holding its maximum value of datetime? In other words, how can I filter by the maximum datetime (grouped by home) and still include other non-grouped, non-aggregate columns (such as player) in the result?
For this sample data:
INSERT INTO TopTen
(id, home, `datetime`, player, resource)
VALUES
(1, 10, '04/03/2009', 'john', 399),
(2, 11, '04/03/2009', 'juliet', 244),
(5, 12, '04/03/2009', 'borat', 555),
(3, 10, '03/03/2009', 'john', 300),
(4, 11, '03/03/2009', 'juliet', 200),
(6, 12, '03/03/2009', 'borat', 500),
(7, 13, '24/12/2008', 'borat', 600),
(8, 13, '01/01/2009', 'borat', 700)
;
the result should be:
id
home
datetime
player
resource
1
10
04/03/2009
john
399
2
11
04/03/2009
juliet
244
5
12
04/03/2009
borat
555
8
13
01/01/2009
borat
700
I tried a subquery getting the maximum datetime for each home:
-- 1 ..by the MySQL manual:
SELECT DISTINCT
home,
id,
datetime AS dt,
player,
resource
FROM TopTen t1
WHERE `datetime` = (SELECT
MAX(t2.datetime)
FROM TopTen t2
GROUP BY home)
GROUP BY `datetime`
ORDER BY `datetime` DESC
The result-set has 130 rows although database holds 187, indicating the result includes some duplicates of home.
Then I tried joining to a subquery that gets the maximum datetime for each row id:
-- 2 ..join
SELECT
s1.id,
s1.home,
s1.datetime,
s1.player,
s1.resource
FROM TopTen s1
JOIN (SELECT
id,
MAX(`datetime`) AS dt
FROM TopTen
GROUP BY id) AS s2
ON s1.id = s2.id
ORDER BY `datetime`
Nope. Gives all the records.
I tried various exotic queries, each with various results, but nothing that got me any closer to solving this problem.
You are so close! All you need to do is select BOTH the home and its max date time, then join back to the topten table on BOTH fields:
SELECT tt.*
FROM topten tt
INNER JOIN
(SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt
ON tt.home = groupedtt.home
AND tt.datetime = groupedtt.MaxDateTime
The fastest MySQL solution, without inner queries and without GROUP BY:
SELECT m.* -- get the row that contains the max value
FROM topten m -- "m" from "max"
LEFT JOIN topten b -- "b" from "bigger"
ON m.home = b.home -- match "max" row with "bigger" row by `home`
AND m.datetime < b.datetime -- want "bigger" than "max"
WHERE b.datetime IS NULL -- keep only if there is no bigger than max
Explanation:
Join the table with itself using the home column. The use of LEFT JOIN ensures all the rows from table m appear in the result set. Those that don't have a match in table b will have NULLs for the columns of b.
The other condition on the JOIN asks to match only the rows from b that have bigger value on the datetime column than the row from m.
Using the data posted in the question, the LEFT JOIN will produce this pairs:
+------------------------------------------+--------------------------------+
| the row from `m` | the matching row from `b` |
|------------------------------------------|--------------------------------|
| id home datetime player resource | id home datetime ... |
|----|-----|------------|--------|---------|------|------|------------|-----|
| 1 | 10 | 04/03/2009 | john | 399 | NULL | NULL | NULL | ... | *
| 2 | 11 | 04/03/2009 | juliet | 244 | NULL | NULL | NULL | ... | *
| 5 | 12 | 04/03/2009 | borat | 555 | NULL | NULL | NULL | ... | *
| 3 | 10 | 03/03/2009 | john | 300 | 1 | 10 | 04/03/2009 | ... |
| 4 | 11 | 03/03/2009 | juliet | 200 | 2 | 11 | 04/03/2009 | ... |
| 6 | 12 | 03/03/2009 | borat | 500 | 5 | 12 | 04/03/2009 | ... |
| 7 | 13 | 24/12/2008 | borat | 600 | 8 | 13 | 01/01/2009 | ... |
| 8 | 13 | 01/01/2009 | borat | 700 | NULL | NULL | NULL | ... | *
+------------------------------------------+--------------------------------+
Finally, the WHERE clause keeps only the pairs that have NULLs in the columns of b (they are marked with * in the table above); this means, due to the second condition from the JOIN clause, the row selected from m has the biggest value in column datetime.
Read the SQL Antipatterns: Avoiding the Pitfalls of Database Programming book for other SQL tips.
Here goes T-SQL version:
-- Test data
DECLARE #TestTable TABLE (id INT, home INT, date DATETIME,
player VARCHAR(20), resource INT)
INSERT INTO #TestTable
SELECT 1, 10, '2009-03-04', 'john', 399 UNION
SELECT 2, 11, '2009-03-04', 'juliet', 244 UNION
SELECT 5, 12, '2009-03-04', 'borat', 555 UNION
SELECT 3, 10, '2009-03-03', 'john', 300 UNION
SELECT 4, 11, '2009-03-03', 'juliet', 200 UNION
SELECT 6, 12, '2009-03-03', 'borat', 500 UNION
SELECT 7, 13, '2008-12-24', 'borat', 600 UNION
SELECT 8, 13, '2009-01-01', 'borat', 700
-- Answer
SELECT id, home, date, player, resource
FROM (SELECT id, home, date, player, resource,
RANK() OVER (PARTITION BY home ORDER BY date DESC) N
FROM #TestTable
)M WHERE N = 1
-- and if you really want only home with max date
SELECT T.id, T.home, T.date, T.player, T.resource
FROM #TestTable T
INNER JOIN
( SELECT TI.id, TI.home, TI.date,
RANK() OVER (PARTITION BY TI.home ORDER BY TI.date) N
FROM #TestTable TI
WHERE TI.date IN (SELECT MAX(TM.date) FROM #TestTable TM)
)TJ ON TJ.N = 1 AND T.id = TJ.id
EDIT
Unfortunately, there are no RANK() OVER function in MySQL.
But it can be emulated, see Emulating Analytic (AKA Ranking) Functions with MySQL.
So this is MySQL version:
SELECT id, home, date, player, resource
FROM TestTable AS t1
WHERE
(SELECT COUNT(*)
FROM TestTable AS t2
WHERE t2.home = t1.home AND t2.date > t1.date
) = 0
This will work even if you have two or more rows for each home with equal DATETIME's:
SELECT id, home, datetime, player, resource
FROM (
SELECT (
SELECT id
FROM topten ti
WHERE ti.home = t1.home
ORDER BY
ti.datetime DESC
LIMIT 1
) lid
FROM (
SELECT DISTINCT home
FROM topten
) t1
) ro, topten t2
WHERE t2.id = ro.lid
I think this will give you the desired result:
SELECT home, MAX(datetime)
FROM my_table
GROUP BY home
BUT if you need other columns as well, just make a join with the original table (check Michael La Voie answer)
Best regards.
Since people seem to keep running into this thread (comment date ranges from 1.5 year) isn't this much simpler:
SELECT * FROM (SELECT * FROM topten ORDER BY datetime DESC) tmp GROUP BY home
No aggregation functions needed...
Cheers.
You can also try this one and for large tables query performance will be better. It works when there no more than two records for each home and their dates are different. Better general MySQL query is one from Michael La Voie above.
SELECT t1.id, t1.home, t1.date, t1.player, t1.resource
FROM t_scores_1 t1
INNER JOIN t_scores_1 t2
ON t1.home = t2.home
WHERE t1.date > t2.date
Or in case of Postgres or those dbs that provide analytic functions try
SELECT t.* FROM
(SELECT t1.id, t1.home, t1.date, t1.player, t1.resource
, row_number() over (partition by t1.home order by t1.date desc) rw
FROM topten t1
INNER JOIN topten t2
ON t1.home = t2.home
WHERE t1.date > t2.date
) t
WHERE t.rw = 1
SELECT tt.*
FROM TestTable tt
INNER JOIN
(
SELECT coord, MAX(datetime) AS MaxDateTime
FROM rapsa
GROUP BY
krd
) groupedtt
ON tt.coord = groupedtt.coord
AND tt.datetime = groupedtt.MaxDateTime
This works on Oracle:
with table_max as(
select id
, home
, datetime
, player
, resource
, max(home) over (partition by home) maxhome
from table
)
select id
, home
, datetime
, player
, resource
from table_max
where home = maxhome
Try this for SQL Server:
WITH cte AS (
SELECT home, MAX(year) AS year FROM Table1 GROUP BY home
)
SELECT * FROM Table1 a INNER JOIN cte ON a.home = cte.home AND a.year = cte.year
Here is MySQL version which prints only one entry where there are duplicates MAX(datetime) in a group.
You could test here http://www.sqlfiddle.com/#!2/0a4ae/1
Sample Data
mysql> SELECT * from topten;
+------+------+---------------------+--------+----------+
| id | home | datetime | player | resource |
+------+------+---------------------+--------+----------+
| 1 | 10 | 2009-04-03 00:00:00 | john | 399 |
| 2 | 11 | 2009-04-03 00:00:00 | juliet | 244 |
| 3 | 10 | 2009-03-03 00:00:00 | john | 300 |
| 4 | 11 | 2009-03-03 00:00:00 | juliet | 200 |
| 5 | 12 | 2009-04-03 00:00:00 | borat | 555 |
| 6 | 12 | 2009-03-03 00:00:00 | borat | 500 |
| 7 | 13 | 2008-12-24 00:00:00 | borat | 600 |
| 8 | 13 | 2009-01-01 00:00:00 | borat | 700 |
| 9 | 10 | 2009-04-03 00:00:00 | borat | 700 |
| 10 | 11 | 2009-04-03 00:00:00 | borat | 700 |
| 12 | 12 | 2009-04-03 00:00:00 | borat | 700 |
+------+------+---------------------+--------+----------+
MySQL Version with User variable
SELECT *
FROM (
SELECT ord.*,
IF (#prev_home = ord.home, 0, 1) AS is_first_appear,
#prev_home := ord.home
FROM (
SELECT t1.id, t1.home, t1.player, t1.resource
FROM topten t1
INNER JOIN (
SELECT home, MAX(datetime) AS mx_dt
FROM topten
GROUP BY home
) x ON t1.home = x.home AND t1.datetime = x.mx_dt
ORDER BY home
) ord, (SELECT #prev_home := 0, #seq := 0) init
) y
WHERE is_first_appear = 1;
+------+------+--------+----------+-----------------+------------------------+
| id | home | player | resource | is_first_appear | #prev_home := ord.home |
+------+------+--------+----------+-----------------+------------------------+
| 9 | 10 | borat | 700 | 1 | 10 |
| 10 | 11 | borat | 700 | 1 | 11 |
| 12 | 12 | borat | 700 | 1 | 12 |
| 8 | 13 | borat | 700 | 1 | 13 |
+------+------+--------+----------+-----------------+------------------------+
4 rows in set (0.00 sec)
Accepted Answers' outout
SELECT tt.*
FROM topten tt
INNER JOIN
(
SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home
) groupedtt ON tt.home = groupedtt.home AND tt.datetime = groupedtt.MaxDateTime
+------+------+---------------------+--------+----------+
| id | home | datetime | player | resource |
+------+------+---------------------+--------+----------+
| 1 | 10 | 2009-04-03 00:00:00 | john | 399 |
| 2 | 11 | 2009-04-03 00:00:00 | juliet | 244 |
| 5 | 12 | 2009-04-03 00:00:00 | borat | 555 |
| 8 | 13 | 2009-01-01 00:00:00 | borat | 700 |
| 9 | 10 | 2009-04-03 00:00:00 | borat | 700 |
| 10 | 11 | 2009-04-03 00:00:00 | borat | 700 |
| 12 | 12 | 2009-04-03 00:00:00 | borat | 700 |
+------+------+---------------------+--------+----------+
7 rows in set (0.00 sec)
SELECT c1, c2, c3, c4, c5 FROM table1 WHERE c3 = (select max(c3) from table)
SELECT * FROM table1 WHERE c3 = (select max(c3) from table1)
Another way to gt the most recent row per group using a sub query which basically calculates a rank for each row per group and then filter out your most recent rows as with rank = 1
select a.*
from topten a
where (
select count(*)
from topten b
where a.home = b.home
and a.`datetime` < b.`datetime`
) +1 = 1
DEMO
Here is the visual demo for rank no for each row for better understanding
By reading some comments what about if there are two rows which have same 'home' and 'datetime' field values?
Above query will fail and will return more than 1 rows for above situation. To cover up this situation there will be a need of another criteria/parameter/column to decide which row should be taken which falls in above situation. By viewing sample data set i assume there is a primary key column id which should be set to auto increment. So we can use this column to pick the most recent row by tweaking same query with the help of CASE statement like
select a.*
from topten a
where (
select count(*)
from topten b
where a.home = b.home
and case
when a.`datetime` = b.`datetime`
then a.id < b.id
else a.`datetime` < b.`datetime`
end
) + 1 = 1
DEMO
Above query will pick the row with highest id among the same datetime values
visual demo for rank no for each row
Why not using:
SELECT home, MAX(datetime) AS MaxDateTime,player,resource FROM topten GROUP BY home
Did I miss something?
In MySQL 8.0 this can be achieved efficiently by using row_number() window function with common table expression.
(Here row_number() basically generating unique sequence for each row for every player starting with 1 in descending order of resource. So, for every player row with sequence number 1 will be with highest resource value. Now all we need to do is selecting row with sequence number 1 for each player. It can be done by writing an outer query around this query. But we used common table expression instead since it's more readable.)
Schema:
create TABLE TestTable(id INT, home INT, date DATETIME,
player VARCHAR(20), resource INT);
INSERT INTO TestTable
SELECT 1, 10, '2009-03-04', 'john', 399 UNION
SELECT 2, 11, '2009-03-04', 'juliet', 244 UNION
SELECT 5, 12, '2009-03-04', 'borat', 555 UNION
SELECT 3, 10, '2009-03-03', 'john', 300 UNION
SELECT 4, 11, '2009-03-03', 'juliet', 200 UNION
SELECT 6, 12, '2009-03-03', 'borat', 500 UNION
SELECT 7, 13, '2008-12-24', 'borat', 600 UNION
SELECT 8, 13, '2009-01-01', 'borat', 700
Query:
with cte as
(
select id, home, date , player, resource,
Row_Number()Over(Partition by home order by date desc) rownumber from TestTable
)
select id, home, date , player, resource from cte where rownumber=1
Output:
id
home
date
player
resource
1
10
2009-03-04 00:00:00
john
399
2
11
2009-03-04 00:00:00
juliet
244
5
12
2009-03-04 00:00:00
borat
555
8
13
2009-01-01 00:00:00
borat
700
db<>fiddle here
This works in SQLServer, and is the only solution I've seen that doesn't require subqueries or CTEs - I think this is the most elegant way to solve this kind of problem.
SELECT TOP 1 WITH TIES *
FROM TopTen
ORDER BY ROW_NUMBER() OVER (PARTITION BY home
ORDER BY [datetime] DESC)
In the ORDER BY clause, it uses a window function to generate & sort by a ROW_NUMBER - assigning a 1 value to the highest [datetime] for each [home].
SELECT TOP 1 WITH TIES will then select one record with the lowest ROW_NUMBER (which will be 1), as well as all records with a tying ROW_NUMBER (also 1)
As a consequence, you retrieve all data for each of the 1st ranked records - that is, all data for records with the highest [datetime] value with their given [home] value.
Try this
select * from mytable a join
(select home, max(datetime) datetime
from mytable
group by home) b
on a.home = b.home and a.datetime = b.datetime
Regards
K
#Michae The accepted answer will working fine in most of the cases but it fail for one for as below.
In case if there were 2 rows having HomeID and Datetime same the query will return both rows, not distinct HomeID as required, for that add Distinct in query as below.
SELECT DISTINCT tt.home , tt.MaxDateTime
FROM topten tt
INNER JOIN
(SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt
ON tt.home = groupedtt.home
AND tt.datetime = groupedtt.MaxDateTime
this is the query you need:
SELECT b.id, a.home,b.[datetime],b.player,a.resource FROM
(SELECT home,MAX(resource) AS resource FROM tbl_1 GROUP BY home) AS a
LEFT JOIN
(SELECT id,home,[datetime],player,resource FROM tbl_1) AS b
ON a.resource = b.resource WHERE a.home =b.home;
Hope below query will give the desired output:
Select id, home,datetime,player,resource, row_number() over (Partition by home ORDER by datetime desc) as rownum from tablename where rownum=1
(NOTE: The answer of Michael is perfect for a situation where the target column datetime cannot have duplicate values for each distinct home.)
If your table has duplicate rows for homexdatetime and you need to only select one row for each distinct home column, here is my solution to it:
Your table needs one unique column (like id). If it doesn't, create a view and add a random column to it.
Use this query to select a single row for each unique home value. Selects the lowest id in case of duplicate datetime.
SELECT tt.*
FROM topten tt
INNER JOIN
(
SELECT min(id) as min_id, home from topten tt2
INNER JOIN
(
SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt2
ON tt2.home = groupedtt2.home
) as groupedtt
ON tt.id = groupedtt.id
Accepted answer doesn't work for me if there are 2 records with same date and home. It will return 2 records after join. While I need to select any (random) of them. This query is used as joined subquery so just limit 1 is not possible there.
Here is how I reached desired result. Don't know about performance however.
select SUBSTRING_INDEX(GROUP_CONCAT(id order by datetime desc separator ','),',',1) as id, home, MAX(datetime) as 'datetime'
from topten
group by (home)
Related
i am trying to get rank and number of same rank by votes but unfortunately no success.
Here my table structure:
| ID| user_id | votes |
| --| ------- | ----- |
| 1 | D10 | 15 |
| 2 | D5 | 9 |
| 3 | D20 | 9 |
| 4 | D23 | 7 |
| 5 | D35 | 3 |
| 6 | D65 | 2 |
I need the rank of user according to votes, referring to above table i need the rank as:
| user_id | Rank|
| ------- | ----|
| D10 | 1 |
| D5 | 2 |
| D20 | 2 |
| D23 | 3 |
| D35 | 4 |
| D65 | 5 |
and also i need the number of rank, referring to above ranks i need:
Rank 1 = 1
Rank 2 = 2
Rank 3 = 1
Rank 4 = 1
rank 5 = 1
i tried to get rank :
SELECT user_id, votes, FIND_IN_SET( votes, (
SELECT GROUP_CONCAT( DISTINCT votes
ORDER BY votes DESC ) FROM table)
) AS rank
FROM votes
the above query i tried referring to this answer to get the ranks but i am getting error:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use
near '( votes , (SELECT GROUP_CONCAT( DISTINCT votes ORDER BY votes DESC
)
i need the desired result using PHP and MySQL.
On MySQL 8+ you could use windows function dense_rank and count over
with votes_rank as (
select *,
dense_rank() over (order by votes desc) as rnk
from votes
) , count_rank as
( select votes_rank.*,
count(*)over (partition by rnk) as cnt
from votes_rank
) select id,
user_id,
votes,
rnk as votes_rank,
cnt as count_rank
from count_rank;
https://dbfiddle.uk/o1DiPyDz
Consider the following data,
CREATE TABLE votes (
id int,
user_id varchar(10),
votes int );
insert into votes values (1,'D10',15), (2,'D5 ',9), (3,'D20',9), (4,'D23',7), (7,'D50',7), (5,'D35',3), (6,'D65',2);
Result:
id user_id votes votes_rank count_rank
1 D10 15 1 1
2 D5 9 2 2
3 D20 9 2 2
4 D23 7 3 2
7 D50 7 3 2
5 D35 3 4 1
6 D65 2 5 1
Edit,
On MySQL version <8
select tbl.id,tbl.user_id,tbl.votes,tbl.rnk,votes_count
from (SELECT a.id,
a.user_id,
a.votes,
count(b.votes)+1 as rnk
FROM votes a
left join votes b on a.votes<b.votes
group by a.id,a.user_id,a.votes
order by a.votes desc
) as tbl
inner join (select rnk,count(rnk) as votes_count
from ( SELECT a.id,
a.user_id,
a.votes,
count(b.votes)+1 as rnk
FROM votes a
left join votes b on a.votes<b.votes
group by a.id,a.user_id,a.votes
order by a.votes desc
) a2
group by rnk
) as tbl1 on tbl1.rnk = tbl.rnk;
https://dbfiddle.uk/XlsBjrZO
during a group project we recent sent out a survey regarding the site we're building. I've put the data into a mysql database and i'm trying to figure out how to count how many times certain scores was given in each category
the table looks like this
+-----------------+--------------+-------------------+
| Design | Ease of use | Responsiveness |
+-----------------+--------------+-------------------+
| 5 | 5 | 5
| 4 | 4 | 4
| 3 | 3 | 3
| 2 | 2 | 2
| 1 | 1 | 1
| 5 | 4 | 2
| 5 | 4 | 4
| 3 | 3 | 3
| 1 | 2 | 2
| 1 | 2 | 2
I've found a query that works for one colum
SELECT Design, COUNT(*) AS num FROM table GROUP BY Design
I would then get
Design | num
-------------
5 | 3
4 | 1
3 | 2
2 | 1
1 | 3
If i were to try
SELECT Design, COUNT(*) AS num1, Ease of use, COUNT(*) as num2 FROM table
GROUP BY Design, Ease of use
The table gets totally messed up.
What I want is to get
Design | num1 | Ease of use | num2 | Responsiveness | num3
------------- --------------------------------------------------
5 | 3 | 5 | 1 | 5 | 1
4 | 1 | 4 | 3 | 4 | 2
3 | 2 | 3 | 2 | 3 | 2
2 | 1 | 2 | 3 | 2 | 4
1 | 3 | 1 | 1 | 1 | 1
Any help would be greatly appreciated
You can unpivot the values and then aggregate. In MySQL, that typically uses union all:
select val, count(*)
from ((select design as val from table) union all
(select ease_of_use from table) union all
(select responsiveness from table
) der
group by val
order by val desc;
For what you want to get, you can do:
select val, sum(design) as design, sum(ease_of_use) as ease_of_use,
sum(responsiveness) as responsiveness
from ((select design as val, 1 as design, 0 as ease_of_use, 0 as responsiveness from table) union all
(select ease_of_use, 0, 1, 0 from table) union all
(select responsiveness, 0, 0, 1 from table
) der
group by val
order by val desc;
I see no reason to repeat the value three times.
Use a synthesized table with the different values, and join this with subqueries that get the counts of each score.
SELECT nums.num AS Design, t1.count AS num1,
nums.num AS `Ease of Use`, t2.count AS num2,
nums.num AS Responsiveness, t3.count AS num3
FROM (SELECT 1 AS num UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) AS nums
LEFT JOIN (
SELECT Design, COUNT(*) AS count
FROM yourTable
GROUP BY Design) AS t1 ON t1.Design = nums.num
LEFT JOIN (
SELECT `Ease of Use`, COUNT(*) AS count
FROM yourTable
GROUP BY `Ease of Use`) AS t2 ON t2.`Ease of Use` = nums.num
LEFT JOIN (
SELECT Responsiveness, COUNT(*) AS count
FROM yourTable
GROUP BY Responsiveness) AS t3 ON t3.Responsiveness = nums.num
DEMO
Here are three ways:
select s.score,
(select count(*) from tbl where `Design` = s.score) as `Design`,
(select count(*) from tbl where `Ease of use` = s.score) as `Ease of use`,
(select count(*) from tbl where `Responsiveness` = s.score) as `Responsiveness`
from (
select Design as score from tbl
union select `Ease of use` from tbl
union select Responsiveness from tbl
) s
order by score desc
http://sqlfiddle.com/#!9/002303/2
select s.score,
(select count(*) from tbl where `Design` = s.score) as `Design`,
(select count(*) from tbl where `Ease of use` = s.score) as `Ease of use`,
(select count(*) from tbl where `Responsiveness` = s.score) as `Responsiveness`
from (select 1 as score union select 2 union select 3 union select 4 union select 5) s
order by score desc
http://sqlfiddle.com/#!9/002303/4
select s.score,
sum(`Design` = score) as `Design`,
sum(`Ease of use` = score) as `Ease of use`,
sum(`Responsiveness` = score) as `Responsiveness`
from (select 1 as score union select 2 union select 3 union select 4 union select 5) s
cross join tbl t
group by s.score
order by s.score desc
http://sqlfiddle.com/#!9/002303/5
They all return the same result:
| score | Design | Ease of use | Responsiveness |
|-------|--------|-------------|----------------|
| 5 | 3 | 1 | 1 |
| 4 | 1 | 3 | 2 |
| 3 | 2 | 2 | 2 |
| 2 | 1 | 3 | 4 |
| 1 | 3 | 1 | 1 |
As #futureweb wrote in the comment, I don't see a reason to repeat the score three times. Though you can if you want using aliases.
If you have millions of rows ;-) and no indexes you would want to get the result with only one table scan. This is possible with:
select
sum(`Design` = 1) as d1,
sum(`Design` = 2) as d2,
sum(`Design` = 3) as d3,
sum(`Design` = 4) as d4,
sum(`Design` = 5) as d5,
sum(`Ease of use` = 1) as e1,
sum(`Ease of use` = 2) as e2,
sum(`Ease of use` = 3) as e3,
sum(`Ease of use` = 4) as e4,
sum(`Ease of use` = 5) as e5,
sum(`Responsiveness` = 1) as r1,
sum(`Responsiveness` = 2) as r2,
sum(`Responsiveness` = 3) as r3,
sum(`Responsiveness` = 4) as r4,
sum(`Responsiveness` = 5) as r5
from tbl
This will return the data you need, but not in the form you'd like:
| d1 | d2 | d3 | d4 | d5 | e1 | e2 | e3 | e4 | e5 | r1 | r2 | r3 | r4 | r5 |
|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|
| 3 | 1 | 2 | 1 | 3 | 1 | 3 | 2 | 3 | 1 | 1 | 4 | 2 | 2 | 1 |
So you would need to post process it.
I have 2 tables and I want to insert data from one table to another based on a condition:
table 1:
user_id,
agency_user_id,
Output from table 1:
user_id agency_user_id
330 20
330 21
239 10
... ..
239 10
239 12
239 9
table 2:
has the same plus some other columns that I don't need at the moment...
Once a user is logged in he has 2 dropdown menus, in one I am listing user_id (not the id but info based on id) and in the other agency_user_id...
So the problem is that I don't want to have 2 times:
239 10
239 10
in table 2... I want only once (unique)...
Here is the query that I used and it doesn't work as I want it:
INSERT INTO table2
(`user_id`,`agency_user_id`)
SELECT `user_id`,`agency_user_id`
FROM table2
WHERE `user_id` AND `agency_user_id` NOT IN (
SELECT `user_id`
FROM table1
);
and now when I check there are duplicate entries in table2...
I know that I am doing something wrong in that WHERE ... NOT IN part...
Any suggestions?
Thanks.
EDIT:
I tried this as well:
INSERT INTO table2
(`user_id`,`agency_user_id`)
SELECT DISTINCT `user_id`,`agency_user_id`
FROM table2
WHERE `user_id` AND `agency_user_id` NOT IN (
SELECT `user_id`
FROM table1
);
Not working...
Current output from table 2
user_id agency_user_id
330 20 => ok
330 21 => ok
239 10 => ok
239 10 => not ok
239 12 => ok
239 9 => ok
and so on...
You can try using a temporary table:
Like the below example:
select * from TABLE1;
+------+------+
| a | b |
+------+------+
| 1 | 2 |
| 3 | 4 |
| 1 | 2 |
| 4 | 5 |
+------+------+
As you can see
1 2
1 2
are repeated
create a temp table:
create temporary table temp1 (a text, b text, c text);
INSERT into this:
insert into temp1 select a,b,count(*) from TABLE1 group by a,b;
select * from temp1;
+------+------+------+
| a | b | c |
+------+------+------+
| 1 | 2 | 2 |
| 3 | 4 | 1 |
| 4 | 5 | 1 |
+------+------+------+
3 rows in set (0.00 sec)
Finally
insert into table2 (a ,b) select a,b from temp;
select * from table2;
+------+------+
| a | b |
+------+------+
| 1 | 2 |
| 3 | 4 |
| 4 | 5 |
+------+------+
3 rows in set (0.00 sec)
Helped me once!!!
I think what you're looking for is DISTINCT:
INSERT INTO table2
(`user_id`,`agency_user_id`)
SELECT DISTINCT `user_id`,`agency_user_id`
FROM table2
WHERE `user_id` NOT IN (
SELECT `user_id`
FROM table1
) AND `agency_user_id` NOT IN (
SELECT `user_id`
FROM table1
);
where I removed created_at and updated_at to avoid duplicates and fixed the NOT IN to apply to both user_id and agency_user_id.
You should probably try something like this:
INSERT INTO table2(`user_id`,`agency_user_id`)
SELECT DISTINCT `user_id`,`agency_user_id`
FROM table1
WHERE `user_id` + `-` + `agency_user_id` NOT IN (SELECT `user_id` + `-` + `agency_user_id` FROM table2);
This will select distinct values from Table1 that are not already in Table2.
The way that you have your insert it is pulling all user_id's from Table2 that are not in Table1. so if you ahve user_id's that are in Table2 that are not in Table1 you will get duplicates.
I have two tables like so:
# Match
id, team1_id , team2_id
-----------------------
1, 10, 20
2, 10, 50
# Team
id, team_name, team_country
---------------------------
10, team A , England
20, team B , France
I'm trying to get the list from Match table with both teams info,
I wanna some thing like :
Team A (England) vs Team B (France)
I tried this one, but I got false team info, some thing wrong with my query for sure.
Here's my query :
SELECT `match`.*,
`t1`.`team_country` as team1_country,
`t2`.`team_country` as team2_country
FROM `match`,
`team` t1 , `team` t2
WHERE `match`.`team1_id` = `t1`.`id` and `match`.`team2_id` = `t2`.`id`
Thanks in advance!
I just fiddled it on my testmachine with postgres. The SQL shouldn't be different:
lara=# create table match ( id serial primary key, team1 int, team2 int);
CREATE TABLE
lara=# create table teams ( id serial primary key, name text, country text);
CREATE TABLE
lara=# insert into match(id, team1, team2) values (1,1,2),(2,1,3),(3,2,1);
INSERT 0 3
lara=# select * from match;
id | team1 | team2
----+-------+-------
1 | 1 | 2
2 | 1 | 3
3 | 2 | 1
(3 rows)
lara=# insert into teams values (1, 't1', 'en');
INSERT 0 1
lara=# insert into teams values (2, 't2', 'de');
INSERT 0 1
lara=# insert into teams values (3, 't3', 'fr');
INSERT 0 1
lara=# select * from match m left join teams t1 on t1.id=m.team1 left join teams t2 on t2.id=m.team2;
id | team1 | team2 | id | name | country | id | name | country
----+-------+-------+----+------+---------+----+------+---------
1 | 1 | 2 | 1 | t1 | en | 2 | t2 | de
2 | 1 | 3 | 1 | t1 | en | 3 | t3 | fr
3 | 2 | 1 | 2 | t2 | de | 1 | t1 | en
So your actual query is correct. A cleaner one would be the following:
SELECT * FROM match m
LEFT JOIN teams t1 ON t1.id=m.team1
LEFT JOIN teams t2 ON t2.id=m.team2;
But your problem is obviously not the SQL.
I have two tables with a single common field.
Here is how these two table structures are
Table 1
+--ID--+--Title----+----others---+
| 123 | Title 1 | other values|
| 124 | Title 2 | other values|
| 125 | Title 3 | other values|
| 126 | Title 4 | other values|
+------+-----------+-------------+
Table 2
+--ID--+--Tag ID--+----others---+
| 123 | 11 | other values|
| 123 | 12 | other values|
| 123 | 13 | other values|
| 123 | 14 | other values|
| 124 | 15 | other values|
| 124 | 16 | other values|
| 125 | 17 | other values|
| 126 | 18 | other values|
+------+----------+-------------+
I want to show that Article ID 123 have 4 tags i.e 11,12,13 & 14 like the table below
+--Article ID--+--Article Title--+--Tags--+--Tag IDs------+
| 123 | Title 1 | 4 | 11, 12, 13, 14|
| 124 | Title 2 | 2 | 15, 16 |
| 125 | Title 3 | 1 | 17 |
| 126 | Title 4 | 1 | 18 |
+--------------+-----------------+--------+---------------+
I'm very new to PHP and MySQL and trying to learn it.
Someone please help me to know how I can get the desired result.
This query should work (with some tweaking).
SELECT `ID` AS `t1`.`Article ID`, `t2`.`Title` AS `Article Title`, COUNT(`t2`.`ID`) AS `Tags`,
GROUP_CONCAT(`t2`.`ID`) AS `Tag IDs` FROM `Articles` AS `t1`
LEFT JOIN `Tags` AS `t2` ON `t1`.`ID` = `t2`.`ID`
GROUP BY `t1`.`ID`
There's a couple of other options to the GROUP_CONCAT function, but the defaults should work fine for what you want.
SELECT t1.id AS 'Article ID',
t1.title AS 'Article Title',
count( t2.tag_id ) AS 'Tags',
GROUP_CONCAT( t2.Tag_Id order by t2.Tag_id ASC) AS `Tag IDs`
FROM table1 t1
JOIN table2 t2 ON ( t1.id = t2.id )
GROUP BY t1.id;
Hope this works!
As somebody already mentioned in the comments, you should use GROUP_CONCAT(). Here are some examples and options - http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
SELECT table1.*,
table2.tagidgroup
FROM table1
INNER JOIN (SELECT id,
Group_concat(tagid SEPARATOR ',' ) AS tagidgroup
FROM table2
GROUP BY id) Table2
ON table1.id = Table2.id
Merging tables is done by using JOIN (LEFT, RIGHT INNER) keyword. For example:
SELECT T1.*, T2.*, COUNT(T2.ID) AS TAG_COUNT, GROUP_CONCAT(T2.ID) AS TAG_IDS
FROM TABLE1 T1
LEFT OUTER JOIN TABLE2 T2
ON T1.TAG_ID = T2.ID
This type of joining structure suggest, that you have a common filed, by which the join itself is made.
In your table structure I assume, that first table T1 is Article's table, second one is Tags table. In this case you need to have a field in your T1 table, which corresponds to the field in T2, this is most probably ID.
Edit: As final step you need to concatenate the results in order to achieve the desired structure, as many of the answers said - use GROUP_CONCAT() function.