Using SQLite.
SELECT c.*,
COUNT(m.course_id) AS "meeting_count",
COUNT(r.meeting_id) AS "race_count"
FROM course c
LEFT JOIN meeting m ON m.course_id = c.id
LEFT JOIN race r ON r.meeting_id = m.id
GROUP BY c.id
Course has meetings has races.
Trying to select the correct count for course meetings and course races. The problem is the above query is returning the same count for "meeting_count" as "race_count". What am I doing wrong?
try adding DISTINCT like COUNT(DISTINCT m.course_id)
Related
I have this query that already works, i need to write count query for this (need pagination), and i have issues using count with DISTINCT ON, anyone knows correct syntax and way to use it, i already googled but was not able to find any count queries with DISTINCT ON
As result i'm expecting total number of rows from this query that already works
select DISTINCT on (csd.team_contest_id)
c.id as contestId
from contest as c
left join company_sponsor_team as csd on csd.contest_id = c.id
left join sponsor as s on s.id = c.sponsor_id
left join team as d on d.id = c.team_id
left join player as m on c.creator_id = m.id
WHERE c.id = c.id
AND ((c.team_id is not null and c.sponsor_id is null and lower(d.name) LIKE LOWER(CONCAT('%TAN%')))
OR (c.team_id is not null and c.sponsor_id is not null and lower(s.name) LIKE LOWER(CONCAT('%TAN%')))
OR (c.team_id is null and lower(s.name) LIKE LOWER(CONCAT('%TAN%')))) AND (CURRENT_DATE < c.archive_date)
If you want to count the number of rows, use a subquery:
select count(*)
from ( <your query here> ) x;
If you have an aversion to subqueries, you can always do:
select count(distinct csd.team_contest_id)
from . . . <the rest of your query here>;
This returns the same value assuming that csd.team_contest_id is not NULL.
I'm writing a query to multiply the count that I receive from subquery to fees amount, But I don't know how to do that. Any help/suggestion?
Oracle query is:
select courseid,coursename,fees*tmp
from course c join registration r on
r.courseid=c.courseid
and tmp IN (select count(*)
from course c join registration r on
r.courseid=c.courseid group by coursename);
I tried to use like a variable tmp ,But i don't think it works in oracle query. Is there an alternative way to do so?
You can't do that, because you can only select data from tables that appeared between FROM and WHERE. The IN operator is a quick way to save having to write a bunch of OR statements, it is not something that can establish a variable in the outer query.
Instead do something like:
select courseid,coursename,fees * COUNT(r.courseID) OVER(PARTITION BY c.coursename)
from course c join registration r on
r.courseid=c.courseid
Edit/update: you noted that this query produces too many rows and you only want to see distinct course names. In that case it would be better to just use the registrations table to count the number of people on the course and then multiply the fees:
SELECT
c.courseid, c.coursename, c.fees * COALESCE(r.numberOfstudents, 0) as courseWorth
FROM
course c
LEFT OUTER JOIN
(select courseid, COUNT(*) as numberofstudents FROM registration GROUP BY courseid) r
ON c.courseID = r.courseid
You can use a windowing function like Caius or you can use a join like this:
select courseid,coursename, fees * COALESCE(sub.cnt,0)
from course c
join registration r on r.courseid=c.courseid
left join (
select coursename, count(*) as cnt
from course c2
join registration r2 on r2.courseid=c2.courseid
group by coursename
) as sub;
note: I make no claim your joins are correct -- I'm basing this query off of your example not on any knowledge of your data model.
I have 3 datasets: company, post, postedited,
I want to count the numbers of companies' post and postedited. some companies post but did not edited.
here is my query :
SELECT company.name, company.id, count(*),
( select count(*)
from post, postedited
where post.id=postedited.post_id)
from company, post as p
where company.id=p.company_id
group by company_id
the outcome of post is right, but the column of postedited is the same. what's wrong with my query?
Your subquery is completely unrelated to the main query. It selects post and postedited and counts. You are showing this result for every row of the main query.
You want the subquery relate to the main query's post. So remove the post table from the subquery's from clause:
(select count(*) from postedited where postedited.post_id = p.id)
Now this subquery selects a count for the post_id of the main query's records. At last you must get the sum of the counts:
select
c.name, c.id, count(*) as posts,
sum(select count(*) from postedited pe where pe.post_id = p.id) as edits
from company c
join post p on p.company_id = c.id
group by c.id;
You can achieve the same thus:
select
c.name, c.id, count(distinct p.id) as posts, count(pe.post_id) as edits
from company c
join post p on p.company_id = c.id
left join postedited pe on pe.post_id = p.id
group by c.id;
SELECT c.name AS companyName
, c.id AS companyID
, COUNT(DISTINCT p.id) AS postCount
, COUNT(DISTINCT pe.post_id) AS postEditCount
FROM company c
LEFT OUTER JOIN post p ON p.Company_ID = c.ID
LEFT OUTER JOIN postEdited pe ON pe.Company_ID = c.ID
GROUP BY c.id, c.name
That will give you a list of all companies in your company table with a count of each of their posts and edited posts. If you need to further query against that dataset, you can. Or you can add a WHERE clause to the above query to filter it.
And I agree, please don't use comma syntax. It's very easy to produce unintended results, and it doesn't give a good representation of what you're actually querying against. Plus, it's no longer standard and being deprecated in many flavors of SQL. Good JOIN syntax will make your life much easier.
Hi all
Im having some problems combining data from 2 tables in to 1 query.
Now I have one table-nr1 with raw data of restaurants and in the other table-nr2 I have a number of restaurants that have been graded.
So, now I want to select all restaurants and at the same time select grades of that restaurant from table-nr2 and get the average value of those grades.
How can I do this in a single SQL query?
SELECT r.*,
COALESCE(
(
SELECT AVG(grade)
FROM table_nr2 g
WHERE g.restaurant_id = r.id
), 0)
FROM table-nr1 r
Assuming your restaurants have a name and id, and the your reviews have a grade
SELECT re.name, avg(ra.grade)
FROM table-nr1 re
LEFT JOIN table-nr2 ra ON re.id = ra.id
GROUP BY re.name
You need to group by all fields you want to select which are not aggregated, and left join means you will get all restaurants, irrespective of whether they have any ratings.
You need to perform a join. In this case an inner left join sounds fine, which is the default join. You can use USING syntax if the field that links them is the same on both sides, so you would end up with something like this:
SELECT table-nr1.*, AVG(table-nr2.score)
FROM table-nr1
JOIN table-nr2 USING (restrauntId)
Otherwise you could do something that links them using an on clause like this:
SELECT table-nr1.*, AVG(table-nr2.score)
FROM table-nr1
JOIN table-nr2 ON (table-nr1.restrauntId = table-nr2.restrauntId)
I'm having problems getting an accurate count of a column after joining others. When a column is joined I would still like to have a DISTINCT count of the table that it is being joined on.
A restaurant has multiple meals, meals have multiple food groups, food groups have multiple ingredients.
Through the restaurants id I want to be able to calculate how many of meals, food groups, and ingrediants the restaurant has.
When I join the food_groups the count for meals increases as well (I understand this is natural behavior I just don't understand how to get what I need due to it.) I have tried DISTINCT and other things I have found, but nothing seems to do the trick. I would like to keep this to one query rather than splitting it up into multiple ones.
SELECT
COUNT(meals.id) AS countMeals,
COUNT(food_groups.id) AS countGroups,
COUNT(ingrediants.id) AS countIngrediants
FROM
restaurants
INNER JOIN
meals ON restaurants.id = meals.restaurant_id
INNER JOIN
food_groups ON meals.id = food_groups.meal_id
INNER JOIN
ingrediants ON food_groups.id = ingrediants.food_group_id
WHERE
restaurants.id='43'
GROUP BY
restaurants.id
Thanks!
The DISTINCT goes inside the count
SELECT
COUNT(DISTINCT meals.id) AS countMeals,
COUNT(DISTINCT food_groups.id) AS countGroups,
COUNT(DISTINCT ingrediants.id) AS countIngrediants
FROM
restaurants
INNER JOIN
meals ON restaurants.id = meals.restaurant_id
INNER JOIN
food_groups ON meals.id = food_groups.meal_id
INNER JOIN
ingrediants ON food_groups.id = ingrediants.food_group_id
WHERE
restaurants.id='43'
GROUP BY
restaurants.id
You're going to have to do subqueries, I think. Something like:
SELECT
(SELECT COUNT(1) FROM meals m WHERE m.restaurant_id = r.id) AS countMeals,
(SELECT COUNT(1) FROM food_groups fg WHERE fg.meal_id = m.id) AS countGroups,
(SELECT COUNT(1) FROM ingrediants i WHERE i.food_group_id = fg.id) AS countGroups
FROM restaurants r
Where were you putting your DISTINCT and on which columns? When using COUNT() you need to do the distinct inside the parentheses and you need to do it over a single column that is distinct for what you're trying to count. For example:
SELECT
COUNT(DISTINCT M.id) AS count_meals,
COUNT(DISTINCT FG.id) AS count_food_groups,
COUNT(DISTINCT I.id) AS count_ingredients
FROM
Restaurants R
INNER JOIN Meals M ON M.restaurant_id = R.id
INNER JOIN Food_Groups FG ON FG.meal_id = M.id
INNER JOIN Ingredients I ON I.food_group_id = FG.id
WHERE
R.id='43'
Since you're selecting for a single restaurant, you shouldn't need the GROUP BY. Also, unless this is in a non-English language, I think you misspelled ingredients.