I'm trying to get the totals of a table grouped by names that are similar. Here is my test mysql:
CREATE TABLE IF NOT EXISTS aa (
clicks INT NOT NULL,
locn varchar (30) NOT NULL
) CHARACTER SET utf8 COLLATE utf8_unicode_ci;
insert into aa values(1, 'page?1'),
(1, 'page?2'),
(1, 'page?3'),
(1, 'item(12)'),
(1, 'item(22)'),
(1, 'item(32)');
If I run this command
SELECT count(clicks), substring_index(locn, '(',1) as a FROM aa group by a;
the result is
3 item
1 page?1
1 page?2
1 page?3
If I run
SELECT count(clicks), substring_index(locn, '?',1) as b FROM aa group by b ;
the result is
1 item(12)
1 item(22)
1 item(32)
3 page
So each of those work but I can't figure out how to get them to work together. Would someone explain how to do this, please?
SELECT count(clicks), substring_index(substring_index(locn, '(', 1), '?', 1) as a
FROM aa group by a;
Result given your data:
+---------------+------+
| count(clicks) | a |
+---------------+------+
| 3 | page |
| 3 | item |
+---------------+------+
SELECT REGEXP_SUBSTR(locn, '\\w+'), COUNT(*)
FROM aa
GROUP BY 1
REGEXP_SUBSTR(locn, '\w+')
COUNT(*)
page
3
item
3
fiddle
Related
I need to get all rows that are in the table A, but joining with the table B (basically a LEFT JOIN), but also, I need to get the A table row itself, for example, with these tables:
Table A:
id
name
1
Random name
2
Random name #2
Table B:
id
parent_id
location
1
2
Location #1
2
2
Location #2
With this query:
SELECT * FROM A
LEFT JOIN B
ON A.id = B.parent_id;
I get something like this:
id
name
id
parent_id
location
1
Random name
NULL
NULL
NULL
2
Random name #2
1
2
Location #1
2
Random name #2
2
2
Location #2
But I want to get something like this:
id
name
id
parent_id
location
1
Random name
NULL
NULL
NULL
2
Random name #2
NULL
NULL
NULL
2
Random name #2
1
2
Location #1
2
Random name #2
2
2
Location #2
As you can see, there is a row by itself of "Random name #2" separated from its joins, how can I do that?
The main idea is that there are an ads table (the table A), but also, there are a subads table (the table B) with little variations of the ads table, and I need to show all ads and subads in a unique query.
Tanks a lot!
Two suggestions:
SELECT * FROM A
INNER JOIN B
ON A.id = B.parent_id
UNION ALL
SELECT *, NULL, NULL, NULL FROM A
or
SELECT A.*,B.*
FROM (SELECT 1 A_ONLY UNION ALL SELECT 0) A_ONLY
CROSS JOIN A
LEFT JOIN B
ON A.id = B.parent_id AND NOT A_ONLY
WHERE A_ONLY OR B.parent_id
The latter is an approach you can use to emulate WITH ROLLUP when that isn't allowed or when you want something slightly different than that produces (here, avoiding a grand total record and avoiding a double record when there are no B rows).
Probably not the best implementation, but until someone comes up with a proper solution...
SELECT A.id, name, B.id, parent_id, location FROM A
LEFT JOIN B
ON A.id = B.parent_id;
UNION ALL
SELECT A.id, name, NULL as id, NULL as parent_id, NULL as location FROM A
WHERE A.id IN (SELECT parent_id FROM B)
Simply UNION ALL with another query taking the values from A that had matches on B, hence no NULL values from the first query.
you need only the NULL added rows from A and the rest of the inner JOIN
CREATE TABLE A
(`id` int, `name` varchar(14))
;
INSERT INTO A
(`id`, `name`)
VALUES
(1, 'Random name'),
(2, 'Random name #2')
;
CREATE TABLE B
(`id` int, `parent_id` int, `location` varchar(11))
;
INSERT INTO B
(`id`, `parent_id`, `location`)
VALUES
(1, 2, 'Location #1'),
(2, 2, 'Location #2')
;
(SELECT A.id as a_id,A.name,B.* FROM A
INNER JOIN B
ON A.id = B.parent_id)
UNION
(SELECT A.*,NULL,NULL,NULL FROM A)
ORDER by a_id,id;
a_id | name | id | parent_id | location
---: | :------------- | ---: | --------: | :----------
1 | Random name | null | null | null
2 | Random name #2 | null | null | null
2 | Random name #2 | 1 | 2 | Location #1
2 | Random name #2 | 2 | 2 | Location #2
db<>fiddle here
You can make INNER JOIN instead of LEFT JOIN and UNION ALL with table A content:
Both queries must return the same number of columns.
SELECT *, NULL, NULL, NULL
FROM A
UNION ALL
SELECT *
FROM A
INNER JOIN B ON A.id = B.parent_id;
I'm using MySQL. How do I return all possible combination from a single column and count total corresponding column. For example:
name | grade
-------------------
john | A
any | B
cindy | C
kim | C
Will return something like this:
mark | count
-------------------
A | 1
B | 1
C | 2
AB | 2
AC | 3
BC | 3
ABC | 4
I've looking for a solution, the closest one is this Return all possible combinations of values within a single column in SQL. But in only generate combination and in ORACLE.
Here is the data set that I created for this question:
CREATE TABLE users
(`name` varchar(5), `grade` varchar(1))
;
INSERT INTO users
(`name`, `grade`)
VALUES
('john', 'A'),
('any', 'B'),
('cindy', 'C'),
('kim', 'C')
;
...and SQL fiddle of same:
http://sqlfiddle.com/#!9/36924d/1
You can use recursive common table expression:
with recursive cte (n) AS
(
select distinct cast(u.grade as char(255)) from users u
union all
select concat(u.grade, c.n)
from users u
join cte c on u.grade != c.n
where position(u.grade in c.n)=0
and u.grade < c.n
)
select c.n, count(*)
from cte c
join users u on position(u.grade in c.n)
group by c.n
See DBFiddle
What I have
I have the following two tables in a MySQL database (version 5.6.35).
CREATE TABLE `Runs` (
`Name` varchar(200) NOT NULL,
`Run` varchar(200) NOT NULL,
`Points` int(11) NOT NULL
) DEFAULT CHARSET=latin1;
INSERT INTO `Runs` (`Name`, `Run`, `Points`) VALUES
('John', 'A08', 12),
('John', 'A09', 3),
('John', 'A01', 15),
('Kate', 'A02', 92),
('Kate', 'A03', 1),
('Kate', 'A04', 33),
('Peter', 'A05', 8),
('Peter', 'A06', 14),
('Peter', 'A07', 5);
CREATE TABLE `Users` (
`Name` varchar(500) NOT NULL,
`NumberOfRun` int(11) NOT NULL
) DEFAULT CHARSET=latin1;
INSERT INTO `Users` (`Name`, `NumberOfRun`) VALUES
('John', 2),
('Kate', 1),
('Peter', 3);
ALTER TABLE `Runs`
ADD PRIMARY KEY (`Run`);
What is my target
John have Users.NumberOfRun=2, so I will extract the 2 top records from Runs table
Kate have Users.NumberOfRun=1, so I will extract the 1 top record from Runs table
Peter have Users.NumberOfRun=3, so I will extract the 3 top records from Runs table
I would like to came to the following result
+-------+-----+--------+
| Name | Run | Points |
+-------+-----+--------+
| John | A01 | 15 |
| John | A08 | 12 |
| Kate | A02 | 92 |
| Peter | A06 | 14 |
| Peter | A05 | 8 |
| Peter | A07 | 5 |
+-------+-----+--------+
What I have tried
First of all, if it was SQL Server I would use ROW_NUMBER() OVER (PARTITION BY ... ORDER BY ) AS [rn] function to the Runs table and then make a JOIN with the Users table on Users.NumberOfRun<=[rn].
I have read this document but it seems that PARTITONING in MySQL it is available since version 8.X, but I am using the 5.6.X version.
Finally, I have tried this query, based on this Stackoverflow answer:
SELECT t0.Name,t0.Run
FROM Runs AS t0
LEFT JOIN Runs AS t1 ON t0.Name=t1.Name AND t0.Run=t1.Run AND t1.Points>t0.Points
WHERE t1.Points IS NULL;
but it doesn't give me the row number, which is essentially for me to make a JOIN as described above.
SQL Fiddle to this example.
A combination of 'group_concat' and 'find_in_set', followed by the filtering using the position returned by 'find_in_set' will do the job for you.
GROUP_CONCAT will sort the data in descending order of points first.
GROUP_CONCAT(Run ORDER BY Points DESC)
FIND_IN_SET will then retrieve the number of rows you want to include in the result.
FIND_IN_SET(Run, grouped_run) BETWEEN 1 AND Users.NumberOfRun
The below query should work for you.
SELECT
Runs.*
FROM
Runs
INNER JOIN (
SELECT
Name, GROUP_CONCAT(Run ORDER BY Points DESC) grouped_run
FROM
Runs
GROUP BY Name
) group_max ON Runs.Name = group_max.Name
INNER JOIN Users ON Users.Name = Runs.Name
WHERE FIND_IN_SET(Run, grouped_run) BETWEEN 1 AND Users.NumberOfRun
ORDER BY
Runs.Name Asc, Runs.Points DESC;
I have this in my database:
75012
75016
94400
94500
94300
78400
I would like to select only the string where only the first two numbers match and show how many 94 there are so it will output 75012 = 2, 94 = 3, 78 = 1.
Here is what I tried:
select cpostal from fiche_personne WHERE cpostal LIKE LEFT(cpostal, 2);
you need to use a group by clause in your query.
SELECT LEFT(cpostal,2), COUNT(*) AS total
FROM fiche_personne
GROUP BY LEFT(cpostal,2)
please note that the COUNT(*) isn't the best way to complete the query but I don't know your actual table structure, so you should change this to an actual column name
select count(cpostal) from fiche_personne WHERE cpostal LEFT(cpostal, 2) = 94;
Resource: https://www.w3schools.com/sql/func_mysql_count.asp
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(i INT NOT NULL PRIMARY KEY);
INSERT INTO my_table VALUES
(75012),
(75016),
(94400),
(94500),
(94300),
(78400);
SELECT MIN(i) i, COUNT(*) total FROM my_table GROUP BY LEFT(i,2);
+-------+-------+
| i | total |
+-------+-------+
| 75012 | 2 |
| 78400 | 1 |
| 94300 | 3 |
+-------+-------+
*None of other available answers solved my problem
I have a table t like this
id,cc,count
'1','HN','22'
'1','US','18'
'1','VN','1'
'2','DK','2'
'2','US','256'
'3','SK','1'
'3','US','66310'
'4','UA','2'
'4','US','263'
'6','FR','7'
'6','US','84'
'9','BR','3'
I want to get the rows for ids with maximum count, like below:
id,cc,count
'1','HN','22'
'2','US','256'
'3','US','66310'
'4','US','263'
'6','US','84'
'9','BR','3'
My current code is like this but I am not getting the expected results:
SELECT t.* FROM t
JOIN (
SELECT
t.id,t.cc
,max(t.count) as max_slash24_count
FROM t
group by t.id,t.cc
) highest
ON t.count = highest.max_slash24_count
and t.cc = highest.cc
Can anybody help me out?
Remove CC column from group by. Try this.
SELECT t.* FROM t
JOIN (
SELECT
t.id
,max(t.count) as max_slash24_count
FROM t
group by t.id
) highest
ON t.count = highest.max_slash24_count
and t.id= highest.id
Try this:
create table t (id varchar(10), cc varchar(10), count varchar(10))
insert into t (id,cc,count) values ('1','HN','22');
insert into t (id,cc,count) values ('1','US','18');
insert into t (id,cc,count) values ('1','VN','1');
insert into t (id,cc,count) values ('2','DK','2');
insert into t (id,cc,count) values ('2','US','256');
insert into t (id,cc,count) values ('3','SK','1');
insert into t (id,cc,count) values ('3','US','66310');
insert into t (id,cc,count) values ('4','UA','2');
insert into t (id,cc,count) values ('4','US','263');
insert into t (id,cc,count) values ('6','FR','7');
insert into t (id,cc,count) values ('6','US','84');
insert into t (id,cc,count) values ('9','BR','3');
select *
from t
where exists (
select *
from t as t1
group by t1.id
having t1.id = t.id and max(t1.count) = t.count
)
Result
ID CC COUNT
-------------
1 HN 22
2 US 256
3 US 66310
4 US 263
6 US 84
9 BR 3
Check SQLFiddle
This question was answered a lot of times on SO. The query is as simple as this:
SELECT m.id, m.cc, m.count
FROM t m # "m" from "max"
LEFT JOIN t b # "b" from "bigger"
ON m.id = b.id # match a row in "m" with a row in "b" by `id`
AND m.count < b.count # match only rows from "b" having bigger count
WHERE b.count IS NULL # there is no "bigger" count than "max"
The real issue on your question is about the column types. If count is char (and not int) then the string comparison happens using the dictionary order, not the numeric order.
For example, if the third row reads:
'1','VN','123'
you might expect it to be selected in the output, because 123 is bigger than 22. This does not happen because, as string, '123' is smaller than '22'.
Even tho, this was already answered, using ROW_NUMBER functionality as in SQL Server is quite fun and interesting: please look at this query:
SELECT TT.Id, TT.cc, TT.count
FROM (
SELECT t.cc
, t.count
, #row_number:=CASE WHEN #Id=Id THEN #row_number+1 ELSE 1 END AS row_number
, #Id:=Id AS Id
FROM t, (SELECT #row_number:=0, #Id:='') AS temp
ORDER BY t.Id, t.count DESC
) AS TT
WHERE TT.row_number = 1
ORDER BY TT.Id;
It produces expected output:
| Id | cc | count |
|----|----|-------|
| 1 | HN | 22 |
| 2 | US | 256 |
| 3 | US | 66310 |
| 4 | US | 263 |
| 6 | US | 84 |
| 9 | BR | 3 |
SQLFiddle
I've taken test data from #Andrey Morozov