I have 2 tables in my DB, first table called "questions" and hold questions with id, second table called "answers" and hold answers for the questions (as multiple choices).
how to select questions that have less than 4 answers?
questions table:
id question
1 what is ...?
2 how many ...?
3 Is ....?
answers table
id question_id answer
1 1 54
2 1 11
3 1 22
4 2 England
5 1 5
6 2 Turkey
how to select questions that have answers less than 4?
thanks,
select questions.id, questions.question from questions
inner join answers on questions.id = answers.question_id
group by questions.id, questions.question having count(questions.id) <4
here you go.
use this :
SELECT *
FROM questions
WHERE id in
(
SELECT question_id
from answers
group by question_id
having count(question_id) <4
)
Related
I've solved one issue and ran into another. Basicaly i want to select question_id, answer and maximum number of occurences. I run my query from basic table that gathers questions and answers to them (question id represents question and answer represents answer from 0 to 5 that corresponds to other table but that doesn't matter).
**survey_result**
question_id
answer (int from 0 to 5)
Sample survey_result:
question_id answer
1 3
1 5
1 2
2 2
2 0
2 4
Here's the query, it's purpose is to check for every single question, which answer (from 0 to 5) occured the most.
select question_id, answer, max(occurence_number) FROM
(select question_id, answer, count(*) as occurence_number
from survey_result
group by question_id, answer
order by question_id asc, occurence_number desc) as results
GROUP BY question_id
So a sub query results in something like this:
question_id answer occurence_number
1 0 12
1 1 20
1 2 34
1 3 5
1 4 9
1 5 15
But main query results something like this:
question_id answer occurence_number
1 0 12
2 0 20
3 0 34
4 0 5
So the problem is that it always shows answer 0, and i want to get correct answer number.
Sadly a bit redundant due to MySQL's lack of a WITH statement, but this should do what you want. In case of a tie, it will return the higher answer.
SELECT s1.question_id, MAX(s1.answer) answer, MAX(s1.c) occurrences
FROM
(SELECT question_id, answer, COUNT(*) c
FROM survey_result GROUP BY question_id,answer) s1
LEFT JOIN
(SELECT question_id, answer, COUNT(*) c
FROM survey_result GROUP BY question_id,answer) s2
ON s1.question_id=s2.question_id
AND s1.c < s2.c
WHERE s2.c IS NULL
GROUP BY question_id
An SQLfiddle to play with.
I think you are overcomplicating it, try this:
select question_id, answer, count(*) as occurence_number
from survey_result
group by question_id, answer
I have a table include some data like that. This is example for question/answer script. ID is auto increment and if PID=0 then it is question, when reply any question then PID is set to question's ID. There is no Subject for replies.
ID PID SUBJECT CONTENT DATE
1 0 First Question This is my first 09/01/2013
2 0 Second Question This is second 09/01/2013
3 1 Yes this is first 09/01/2013
4 2 I agree this is second 10/01/2013
5 0 Third Question This is third question 11/01/2013
6 1 Reply to first 11/01/2013
7 1 Another reply to first 12/01/2013
8 5 This is reply of 5th 13/01/2013
9 2 Last try for second 14/01/2013
My questions are,
How can I select questions with reply count?
Ex.
First Question (3)
Second Question (2)
Third Question (1)
How can I select today's answered questions or answers?
Ex. For 09/01/2013
First Question (2) ---> 1 question and 1 answer but 2 actions
Second Question (1) ---> just 1 question
Select the questions and join against the answers:
select q.id, q.subject, count(a.id)
from yourtable q
left join yourtable a on q.id=a.pid
where q.pid=0
group by q.id;
Try join for first task
SELECT
q.id as ID,
q.pid as PID,
q.subject as SUBJECT,
COUNT(lq.id) as Total
FROM questions as q
LEFT JOIN questions as lq ON lq.pid = q.ID
WHERE q.PID = 0
GROUP BY q.id
OUTPUT
ID PID SUBJECT TOTAL
1 0 First Question 3
2 0 Second Question 2
5 0 Third Question 1
Demo
EDITS :
For second part. You should note that there can be many other ways for doing the same task.
SELECT
q.id as ID,
q.pid as PID,
q.subject as SUBJECT,
(COUNT(lq.id) - 1) as Total,
q.date
FROM questions as q
LEFT JOIN questions as lq ON lq.pid = q.ID OR lq.id = q.PID
WHERE q.date = DATE(NOW())
OUTPUT
ID PID SUBJECT TOTAL DATE
1 0 First Question 2 January, 09 2012 00:00:00+0000
2 0 Second Question 1 January, 09 2012 00:00:00+0000
Demo
For question 1
select PID,count(*) from table
where pid<>0
group by PID
For question 2
select PID,count(*) from table
where pid<>0 and date=current_date()
group by PID
I just asked this question Find the oldest record in a join between two tables and got a great answer to my question. The problem is that is is not quite what I was looking for (my fault)
Consider the following MySQL tables
Table: Questions
ID
Table: Results
ID
Created - When this record was added.
Q_ID - A FK to the Question table
Example data
Table: Questions
ID
----
1
8
15
55
Table: Results
ID | Created | Q_ID
--------------------
1 | 12:02 | 1
2 | 12:03 | 15
3 | 12:04 | 8
Using the following query, it will return all the records that do not have results associated with them, if all records have results then it will return the question with the oldest result.
SELECT *
FROM
questions
LEFT JOIN results
ON results.q_id = questions.id
ORDER BY
ISNULL(results.id) DESC, results.created ASC
LIMIT 1
What I am actually looking for is for any question that has not been answered, then to sort the question my the count of how many times they have been answered. The lest answered questions should be at the top.
This would give you each question, and the number of results associated it (even if no results exist). They will be ordered with the lowest count at the top:
SELECT Questions.ID, COUNT(Results.ID) Result_Count
FROM
Questions
LEFT JOIN Results ON Questions.ID = Results.Q_ID
GROUP BY Questions.ID
ORDER BY COUNT(Results.ID)
Is this what you had in mind?
I have a simple query doubt.
Question Table
qid question
1 ques1
2 ques2
3 ques3
4 ques4
5 ques5
6 ques6
7 ques7
Answer Table
ansid qid answer
1 1 ans1
2 2 ans2
3 2 ans3
4 4 ans4
5 6 ans5
I have two tables. One for questions and one for answers. Question id(qid) is use as a foreign key in answer table. I want select questions which doesnot have an answer in the answer table. In the above example I need questions 3,5,7. My database is large it may contain more than 50,000 records.
Thanks
ARun
select q.* from question as q
left join answer as a
on q.id = a.qid
where a.qid is null
edit.
Moreover it would be better to add an index on answer table
alter table answer add index iq (qid);
select * from question where qid not in
(select qid from answer)
I have 2 mysql tables
1. questions: with the following columns: id, title, answer1, answer2, answer3, answer4, answer5, nranswers.
and
2. answers with the following columns: id, questionid, userid, answer
Every question has maximum 5 answers( it can have between 2 and 5 answers). My problem is that I want to select from my database, for a given question, how many times was every option selected.
For example, let's suppose I have the question with the id 46, with 4 answers, and 48 users voted for the option #2, 37 users for the option #1 and 39 for the option #4.
I want a query that selects that and write these things:
1 37
2 48
3 0
4 39
P.S. VERY IMPORTANT! IT MUST COUNT ONLY NRANSWERS ANSWERS, AND IT MUST ECHO THE ONES THAT WEREN'T VOTED BEFORE.
Best way to do this: change table defs:
Questions (Question_ID, title)
Answers (Answer_ID, Question_ID, answer_text)
Votes (User_ID, Answer_ID)
Which contains the same data as your def, but is in first normal form. Selecting the counts is now really easy
SELECT
a.Answer_ID,
COUNT(v.User_ID)
FROM
Questions q
LEFT JOIN Answers a ON q.Question_ID = a.Question_ID
LEFT JOIN Votes v ON a.Answer_ID = v.Answer_ID
WHERE q.Question_ID = 46 -- or any other question ID
GROUP BY a.Answer_ID
ORDER BY a.Answer_ID;
SELECT q.id as question, a.answer as answer, count(a.answer) as count FROM questions q, answers a Group by q.id,a.answer
Problem with above that it will return as follows
question answer Count
1 1 37
1 2 48
1 4 39
1 3 0 this is missing
OR
SELECT a.question_id, a.answer, count(a.answer) FROM test.answers a Group by a.question_id, a.answer