I have a table having three columns:
A B C
1 2 2
2 2 2
3 1 1
4 1 2
I want the count of those values which have C equal to 2 but with distinct values of B
So in this case for C = 2, count = 2 (B=2 and B=1)
I used the following command:
Select count(*) from mytable where C=2 group by (B)
but it yields:
count(*)
3
I have tried using "distinct" but it can't be use to select from one column
Have you tried
SELECT COUNT(DISTINCT B) FROM mytable WHERE C = 2;
Use sub query like this:
Select count(*) from (
select distinct B where c=2
)
Related
I have a table with 6 digit numbers that can range from 0-9 and I would match that against a number in 6 categories
first number match
first two number match
first three number match
first four number match
first five number match
all numbers match
But only the highest category per matching number should be selected. An example
Number: 123456
If one has the number [123]756 then this would fall into category first three number match
On number 023456 then this would be no match
I created a fiddle for it https://www.db-fiddle.com/f/TZCrFPnJpkw4fyxA5Q6mR/1
Here an example:
Numbers:
number
123456
123000
023456
123477
133456
Number to match against: 123456 should return
common_digits
number
6
123456
3
123000
0
023456
4
123477
1
133456
What would be an efficient method? The brute force solution would be a double loop I suppose starting with 6 matches, 5 matches, ...
SELECT #number tested_number, 7 - LENGTH(nums.num) common_digits, bids.*
FROM bids
JOIN (SELECT 1 num UNION
SELECT 10 UNION
SELECT 100 UNION
SELECT 1000 UNION
SELECT 10000 UNION
SELECT 100000) nums
WHERE #number DIV nums.num = bids.ticketNumber DIV nums.num
ORDER BY nums.num LIMIT 1;
https://www.db-fiddle.com/f/TZCrFPnJpkw4fyxA5Q6mR/4
You can do:
select *
from (
select 6 as score, b.* from bids b where ticketNumber like '123456%'
union all select 5, b.* from bids b where ticketNumber like '12345%'
union all select 4, b.* from bids b where ticketNumber like '1234%'
union all select 3, b.* from bids b where ticketNumber like '123%'
union all select 2, b.* from bids b where ticketNumber like '12%'
union all select 1, b.* from bids b where ticketNumber like '1%'
) x
order by score desc
limit 1
Result:
score id roundId address ticketNumber
------ --- -------- -------- ------------
6 1 1 12345 123456
See example at DB Fiddle.
Alternatively you can use a recursive CTE, but that's not available in MySQL 5.7 (as your fiddle implies).
I have a table with 3 columns (A,B,C). I want to select some rows from the table and then the MySQL to return a single row having the values added on each column.
A B C
1. 2 2 2
2. 4 4 4
3. 6 7 8
MySQL should return in this case, if I select all the three rows:
A B C
1. 12 13 14
select sum(A),sum(B),sum(C) from mytable where id in (1,2,3);
select
sum(a) as atotal,
sum(b) as btotal,
sum(c) as ctotal
from
yourtable t
where
t.id in (1, 2, 3)
Try this:
select sum(a), sum(b), sum(c)
from your_table
Hi there m trying to calculate the row count for same value,
id,value
1 | a
2 | b
3 | c
4 | d
5 | e
and my query is
select value, count(*) as Count from mytable where id in('4','2','4','1','4') group by value having count(*) > 1
for which my expected output will be,
value,Count
d | 3
b | 1
a | 1
Thanks, any help will be appreciated
Try that:
SELECT value, count(value) AS Count
FROM mytable m
WHERE value = m.value
GROUP BY value
SELECT t.id, t.value, COUNT(t.id)
FROM
test t
JOIN
( SELECT 1 AS id
UNION ALL SELECT 3
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 1
UNION ALL SELECT 1 ) AS tmp
ON t.id = tmp.id
GROUP BY t.id
Sample on sqlfiddle.com
See also: Force MySQL to return duplicates from WHERE IN clause without using JOIN/UNION?
Of course, your IN parameter will be dynamic, and thus you will have to generate the corresponding SQL statement for the tmp table.
That's the SQL-only way to do it. Another possibility is to have the query like you have it in your question and afterwards programmatically associate the rows to the count passed to the IN parameter.
I want to group items only when there are more than 2 rwos matching rule. How can this be done?
E.G: (grouping by Col)
Col
----
A
A
B
B
B
Should return:
Col | count(*)
---------------
A 2
A 2
B 3
It only displays B once since there are more than 3 results.
Since MySQL doesn't have COUNT OVER you need a inline view to get the counts for when the count is less then 3. Then its just a union to a normal count query
SELECT counts.col,
counts.k
FROM test
INNER JOIN (SELECT col,
COUNT(col) k
FROM test
GROUP BY col
having count(col) < 3 ) counts
ON test.col = counts.col
UNION ALL
SELECT col,
COUNT(col) k
FROM test
GROUP BY col
HAVING COUNT(col) > 2
See it working here
I have a table with 3 columns (A,B,C). I want to select some rows from the table and then the MySQL to return a single row having the values added on each column.
A B C
1. 2 2 2
2. 4 4 4
3. 6 7 8
MySQL should return in this case, if I select all the three rows:
A B C
1. 12 13 14
select sum(A),sum(B),sum(C) from mytable where id in (1,2,3);
select
sum(a) as atotal,
sum(b) as btotal,
sum(c) as ctotal
from
yourtable t
where
t.id in (1, 2, 3)
Try this:
select sum(a), sum(b), sum(c)
from your_table