I have the following query:
SELECT a.feeder_id, b.feeder_pr
FROM authors_article_feeders a
LEFT JOIN feeders b ON b.id = a.feeder_id
WHERE website_id =1
LIMIT 0 , 30
which results in:
feeder_id feeder_pr
18 2
18 2
18 2
18 2
32 6
What I need is to modify the above query so that it will manipulate this data so that the result would end up with a count of each feeder_pr, so in this case the result would be:
feeder_pr count
2 4
6 1
Any assistance is appreciated. If you have time please describe your solution so that I can learn from it while I'm at it.
Everything I've tried has ended in inaccurate results, usually with just one row instead of the expected 2.
You just need to add a GROUP BY And, you would not even need the joins
SELECT b.feeder_pr, COUNT(b.feeder_pr)
FROM feeders b
GROUP BY b.feeder_pr
SELECT b.feeder_pr, count(a.feeder_id) as count
FROM authors_article_feeders a
LEFT JOIN feeders b ON b.id = a.feeder_id
WHERE website_id =1
GROUP BY 1
Related
I have a MySQL table as below
ID SHEET_NUMBER DAYS RESULT
1 55201 9 10
2 55209 28 25.5
3 55209 28 27.9
4 38558 7 12
5 38552 5 19
6 38559 5 5
I want to select only rows with firstly matching sheet numbers & only if there if there is a matching pair of 28 days specimens
so if there is only one 28 day it will select nothing but if there is at least 2x 28 day it will get both rows
I'm totally lost, i know i should be using group by.. but i'm unsure of its use.
thankyou
Can you try the following query:
SELECT *
FROM test
WHERE sheet_number IN (
SELECT sheet_number
FROM test
WHERE days = 28
GROUP BY sheet_number
HAVING COUNT(*) >= 2
);
Here's the SQL Fiddle.
First, write a query that finds sheet_number with two or more rows with days value of 28.
SELECT d.sheet_number
FROM my_table_below d
WHERE d.days = 28
GROUP BY d.sheet_number
HAVING COUNT(1) > 1
With that query, we can use that as an inline view, and join back to the original table to find the matching rows:
SELECT t.*
FROM ( SELECT d.sheet_number
FROM my_table_below d
WHERE d.days = 28
GROUP BY d.sheet_number
HAVING COUNT(1) > 1
) m
JOIN my_table_below t
ON t.sheet_number = m.sheet_number
AND t.days = 28
ORDER BY t.sheet_number, t.id
Omit the condition t.days = 28 on the outer query, if the specification is to return all of the rows for the sheet_number, not just the rows with days=28. (The specification is a bit unclear.)
I did some research and learned about the COALESCE(sum(num), 0) function. The issue is the example I found only related to using one table.
I am calculating a sum from a second table, and if there are no records for an item in the second table, I still want it to show up in my query and have a sum of zero.
SELECT note.user, note.product, note.noteID, note.note, COALESCE(sum(noteTable.Score), 0) as points
FROM note, noteTable
WHERE note.user <> 3 AND note.noteID = noteTable.noteID
I am only recieving results if there is an entry in the second table noteTable. If there are scores added for a note, I still want them to show up in the result with a points value of zero.
Table Examples:
Note
user | product | noteID |note
3 1 1 Great
3 2 2 Awesome
4 1 3 Sweet
NoteTable
noteID | score
1 5
The query should show me this:
user | noteID | sum(points)
3 1 5
3 2 0
4 3 0
But I am only getting this:
user | noteID | sum(points)
3 1 5
http://sqlfiddle.com/#!9/aae812/2
SELECT
note.user,
note.product,
note.noteID, note.note,
COALESCE(sum(noteTable.Score),0) as points
FROM note
LEFT JOIN noteTable
ON note.noteID = noteTable.noteID
WHERE note.user <> 3
and I guess you should add:
GROUP BY note.noteid
if you expect to get SUM for every user. So you want to get more then 1 record back.
First, learn to use proper JOIN syntax and table aliases. The answer to your question is SUM() along with COALESCE():
SELECT n.user, n.product, n.noteID, n.note,
COALESCE(sum(nt.Score), 0) as points
FROM note n LEFT JOIN
noteTable nt
ON n.noteID = nt.noteID
WHERE n.user <> 3
GROUP BY n.user, n.product, n.noteID, n.note;
You also need a GROUP BY.
I have a table for terminal
Id status
1 Online
2 Offline
3 Offline
and I have a separate table where I can find the total hours/date of the up and downtime.
total_time
Id up down
1 10 14
2 20 4
3 15 9
1 5 19
2 4 20
3 10 14
I want to display the terminal id, status and the TOTAL up and downtime(1 = 15(up), 2 = 24(up), 3 = 25(up). I'm using inner join and I have no idea how i will be able to get the sum of the up and downtime..
SELECT terminal.Id, terminal.status, total_time.Id, SUM(total_time.up),SUM(total_time.down)
FROM terminal
INNER JOIN total_time
ON terminal.Id = total_time.Id
WHERE terminal.Id = total_time.Id
Something like this should do the trick. I am interpreting your question as asking for only the sum of the time of the current status. If this is not what you want (and maybe you want the sum of both times), please let me know.
SELECT t.id, t.status, IF(t.status = 'Online', ttlTime.upTime, ttlTime.downTime) as totalTime
FROM terminal t
JOIN
(SELECT tt.id, SUM(tt.up) as upTime, SUM(tt.down) AS downTime
FROM total_time tt
GROUP BY tt.id) ttlTime ON t.id = ttlTime.id
See the SQLFiddle
You get "inner sums" by using the GROUP BY clause.
Try:
SELECT terminal.Id, SUM(total_time.up), SUM(total_time.down)
FROM terminal
INNER JOIN total_time
ON terminal.Id = total_time.Id
GROUP BY terminal.Id
SELECT DISTINCT terminal.Id, terminal.status, total_time.Id, SUM(total_time.up),SUM(total_time.down)
FROM terminal
INNER JOIN total_time
ON terminal.Id = total_time.Id
Should do it. The DISTINCT clause acts as a filter to remove duplicate records from a result set.
I have a table with columns similar to below , but with about 30 date columns and 500+ records
id | forcast_date | actual_date
1 10/01/2013 12/01/2013
2 03/01/2013 06/01/2013
3 05/01/2013 05/01/2013
4 10/01/2013 09/01/2013
and what I need to do is get a query with output similar to
week_no | count_forcast | count_actual
1 4 6
2 5 7
3 2 1
etc
My query is
SELECT weekofyear(forcast_date) as week_num,
COUNT(forcast_date) AS count_forcast ,
COUNT(actual_date) AS count_actual
FROM
table
GROUP BY
week_num
but what I am getting is the forcast_date counts repeated in each column, i.e.
week_no | count_forcast | count_actual
1 4 4
2 5 5
3 2 2
Can any one please tell me the best way to formulate the query to get what I need??
Thanks
try:
SELECT weekofyear(forcast_date) AS week_forcast,
COUNT(forcast_date) AS count_forcast, t2.count_actual
FROM
t t1 LEFT JOIN (
SELECT weekofyear(actual_date) AS week_actual,
COUNT(forcast_date) AS count_actual
FROM t
GROUP BY weekOfYear(actual_date)
) AS t2 ON weekofyear(forcast_date)=week_actual
GROUP BY
weekofyear(forcast_date), t2.count_actual
sqlFiddle
You have to write about 30 (your date columns) left join, and the requirement is that your first date column shouldn'd have empty week (with a count of 0) or the joins will miss.
Try:
SELECT WeekInYear, ForecastCount, ActualCount
FROM ( SELECT A.WeekInYear, A.ForecastCount, B.ActualCount FROM (
SELECT weekofyear(forecast_date) as WeekInYear,
COUNT(forecast_date) as ForecastCount, 0 as ActualCount
FROM TableWeeks
GROUP BY weekofyear(forecast_date)
) A
INNER JOIN
( SELECT * FROM
(
SELECT weekofyear(forecast_date) as WeekInYear,
0 as ForecastCount, COUNT(actual_date) as ActualCount
FROM TableWeeks
GROUP BY weekofyear(actual_date)
) ActualTable ) B
ON A.WeekInYear = B.WeekInYear)
AllTable
GROUP BY WeekInYear;
Here's my Fiddle Demo
Just in case someone else comes along with the same question:
Instead of trying to use some amazing query, I ended up creating an array of date_columns_names and a loop in the program that was calling this query, and for each date_column_name, performing teh asme query. It is a bit slower, but it does work
My database tracks sections users have completed:
Table 'users':
id user_id sections_id
//
4 46 1
5 46 2
6 46 4
7 46 5
//
Table 'sections':
id header_id name
1 1 1/3
2 1 2/3
3 1 3/3
4 2 1/3
5 2 2/3
6 2 3/3
The following query
SELECT a.sections_id
,b.header_id
FROM users a
JOIN sections b
ON a.sections_id = b.id
WHERE a.user_id = 46;
// a.user_id can be just user_id, but added for clarity
Gives me:
sections_id header_id
1 1
2 1
4 2
5 2
What I want is max section ID per header for a particular user, so that I know which section I need to serve the user:
sections_id header_id
2 1
5 2
I'm assuming this is a max per group problem, but I can't quite get my head around the solution. I could throw all the data into my PHP and parse out from there, but it seems I should be able to do it via the SQL. TIA!
This is a simple group by query:
SELECT s.header_id, max(u.sections_id)
FROM users u JOIN
sections s
ON u.sections_id = s.id
WHERE u.user_id = 46
group by s.header_id;
I also changed your aliases to be the initials of the table. This makes the query much easier to follow.
Edit: SQLFiddle Here: http://sqlfiddle.com/#!2/dbb5a/2
You could add a group by clause with a max() function
SELECT max(a.sections_id)
,b.header_id
FROM users a
JOIN sections b
ON a.sections_id = b.id
WHERE a.user_id = 46
GROUP BY header_id;