Update: I want to use dynamic sql to select question as column and put answer in row, like cursor or loop, is that possible?
I want the select result like this
+--------+---------------+--------------------------------------------------------------------------+
| userid | Living Status | This is another question get from row and it's longer than 64 characters |
+--------+---------------+--------------------------------------------------------------------------+
| 19 | married | q2_opt3 |
+--------+---------------+--------------------------------------------------------------------------+
And here is my query
select
userid,
min(if(question.ordering=1,o.name,NULL )) as 'Living Status',
min(if(question.ordering=2,o.name,NULL )) as 'This is another question get from row and it's longer than 64 characters'
from answer
inner join question on question.key_value = answer.key_value
inner join q_option o on question.id = o.question_id and o.value = answer.answer
where userid in (19)
GROUP BY id
The question table is like
+----+----------+---------------------------------------------------------------------------+--------------+
| id | ordering | question | key_value |
+----+----------+---------------------------------------------------------------------------+--------------+
| 1 | 1 | Living Status | livingStatus |
| 2 | 2 | This is another question get from row and it's longer than 64 characters | question_2 |
+----+----------+---------------------------------------------------------------------------+--------------+
The answer table is like
+----+--------+--------------+--------+
| id | answer | key_value | userid |
+----+--------+--------------+--------+
| 1 | 2 | livingStatus | 19 |
| 2 | 3 | question_2 | 19 |
+----+--------+--------------+--------+
The q_option table is like
+----+----------+-------------+-------+
| id | name | question_id | value |
+----+----------+-------------+-------+
| 1 | single | 1 | 1 |
| 2 | married | 1 | 2 |
| 3 | divorced | 1 | 3 |
| 4 | q2_opt1 | 2 | 1 |
| 5 | q2_opt2 | 2 | 2 |
| 6 | q2_opt3 | 2 | 3 |
+----+----------+-------------+-------+
Related
I have this tables People, Ticket, and Report.
+----------+-------+-----+
| idPeople | Name | Age |
+----------+-------+-----+
| 1 | Name1 | 21 |
| 2 | Name2 | 37 |
| 3 | Name3 | 28 |
+----------+-------+-----+
I would like to replace the ForeingKey idPeople with columns Name and Age from People table.
+----------+------------+------------+----------+
| idTicket | ticketCol2 | ticketCol3 | idPeople |
+----------+------------+------------+----------+
| 5 | True | 01/06/99 | 1 |
| 6 | False | 01/06/99 | 2 |
| 7 | True | 01/06/99 | 4 |
+----------+------------+------------+----------+
In the Report table replace the Foreing Key idTicket with ticketCol2, Name, Age from the previous table Ticket with replaced columns (idPeople by Name, Age).
+----------+----------+------------+------------+
| idReport | idTicket | ReportCol3 | ReportCol4 |
+----------+----------+------------+------------+
| 1 | 5 | 01/06/99 | blabla |
| 2 | 7 | 01/06/99 | asdfdd |
| 2 | 6 | 01/06/99 | fooboo |
+----------+----------+------------+------------+
And I the result should be like this table and must be done in one query.
+----------+------------+------------+------------+------------+------+-----+
| idReport | ticketCol2 | ticketCol3 | ReportCol3 | ReportCol4 | Name | Age |
+----------+------------+------------+------------+------------+------+-----+
| 1 | 01/06/99 | abcd | blabla | 123456 | Name | 20 |
| 2 | 01/06/99 | bcda | asdfdd | 321456 | Name | 23 |
| 3 | 01/06/99 | asdf | fooboo | 123456 | Name | 28 |
+----------+------------+------------+------------+------------+------+-----+
I Have tried replacing the foreingkeys with LEFT JOIN and bringing some columns Name and Age to the Ticket table but now the last part where I should replace idTicket with Columns from Ticket is not working.
I have read about the nested JOINs but I cannot understand it very well, I would really appreciate some idea of how I can do it or what should I investigate. Are nested Joins the right way?
The query that I've tried to accomplish the Table Ticket.
SELECT Ticket.ticketCol2, Ticket.ticketCol3, p.Name 'Name', p.Age 'Age'
from Ticket
left join people p on (Ticket.idPeople=p.idPeople);
Try something like this:
SELECT Report.idReport,
Ticket.ticketCol2,
Ticket.ticketCol3,
Report.ReportCol3,
Report.ReportCol4,
People.Name,
People.Age
FROM People
LEFT JOIN Ticket ON Ticket.idPeople = People.idPeople
LEFT JOIN Report ON Report.idTicket = Ticket.idTicket
Like #RiggsFolly said, the Ticket.idPeople won´t match to the People.idPeople, so this will not match any rows.
I have a question and answer website like stackoverflow. Here is the structure of some tables:
-- {superfluous} means some other columns which are not related to this question
// q&a
+----+-----------------+--------------------------+------+-----------+-----------+
| id | title | body | type | related | author_id |
+----+-----------------+--------------------------+------+-----------+-----------+
| 1 | How can I ... | I'm trying to make ... | q | NULL | 3 |
| 2 | | You can do that by ... | a | 1 | 1 |
| 3 | Why should I .. | I'm wonder, why ... | q | NULL | 1 |
| 4 | | First of all you ... | a | 1 | 2 |
| 5 | | Because that thing ... | a | 3 | 2 |
+----+-----------------+--------------------------+------+-----------+-----------+
// users
+----+--------+-----------------+
| id | name | {superfluous} |
+----+--------+-----------------+
| 1 | Jack | |
| 2 | Peter | |
| 3 | John | |
+----+--------+-----------------+
// votes
+----+----------+-----------+-------+-----------------+
| id | user_id | post_id | value | {superfluous} |
+----+----------+-----------+-------+-----------------+
| 1 | 3 | 4 | 1 | |
| 2 | 1 | 1 | -1 | |
| 3 | 2 | 1 | 1 | |
| 4 | 3 | 2 | -1 | |
| 5 | 1 | 4 | 1 | |
| 6 | 3 | 5 | -1 | |
+----+--------+-------------+-------+-----------------+
// tags
+----+------------+-----------------+
| id | name | {superfluous} |
+----+------------+-----------------+
| 1 | PHP | |
| 2 | SQL | |
| 3 | MySQL | |
| 4 | HTML | |
| 5 | CSS | |
| 6 | C# | |
+----+------------+-----------------+
// q&aTag
+-------+--------+
| q&aid | tag_id |
+-------+--------+
| 1 | 1 |
| 1 | 4 |
| 3 | 5 |
| 3 | 4 |
| 4 | 6 |
+-------+--------+
Now I need to find top users in a specific tag. For example, I need to find Peter as top user in PHP tag. Because his answer for question1 (which has PHP tag) has earned 2 upvotes. Is doing that possible?
Try this:
select q1.title, u.id, u.name, sum(v.value) total from `q&a` q1
left join `q&atag` qt ON q1.id = qt.`q&aid`
inner join tags t ON qt.tag_id = t.id
left join `q&a` q2 ON q2.related = q1.id
left join users u ON q2.author_id = u.id
left join votes v ON v.post_id = q2.id
where t.name = 'PHP'
group by q1.id, u.id
and here is a simple divided solution:
Let us divide it into sub queries:
get the id of the tag you will search for: select id from tags where name = 'PHP'
get the questions with this tag: select 'q&aid' from 'q&aTag' where tag_id = 1.
get the ids of answers for that question: select id, author_id fromq&awhere related in (2.)
get the final query: select user_id, sum(value) from votes where post_id in (3.) group by user_id
Now combining them all give the result:
select user_id, sum(`value`) total from votes
where post_id in (
select id from `q&a` where related in (
select `q&aid` from `q&aTag` where tag_id IN (
select id from tags where name = 'PHP'
)
)
)
group by user_id
you can add this at the end if you want only one record:
order by total desc limit 1
I need to join 3 different MySQL tables:
The questions table (represents a questio)
The questions votes table (represents a like to the question when Sign=1 and an unlike when Sign=0)
The answers table (represents a table with the answers to an specific question).
The three tables have this structure:
Questions
--------------------------------------------
| ID | UserID | Title | Body | Date
--------------------------------------------
| 1 | 32 | Is it raining? | BodyQuestion | 01/01/2016
| 2 | 45 | Who are we? | BodyQuestion | 02/02/2016
--------------------------------------------
QuestionsVotes
--------------------------------------------
| ID | QuestionID | Sign
--------------------------------------------
| 1 | 1 | 1
| 2 | 2 | 1
| 3 | 1 | 0
| 4 | 1 | 1
| 5 | 2 | 0
Answers
--------------------------------------------
| ID | QuestionID | UserID | Body
--------------------------------------------
| 1 | 1 | 45 | Yes, it is.
| 2 | 2 | 10 | Tricky question...
| 3 | 1 | 67 | In Barcelona it is not
What I need is a SQL query that returns, given the ID of a Question, to return as much rows as number of answers the question has received each one with the Questions.ID, Questions.UserID, Questions.Title, Questions.Body, Questions.Date, the likes associated to the question, the unlikes associated with the question, Answers.ID, Answers.UserID. As you see, the only change between the rows are the Answers fields.
SQL Output (for Question with ID=1)
--------------------------------------------
| ID | UserID | Title | Body | Date | Likes | Unlikes | AnswerID | AnswerUserID
--------------------------------------------
| 1 | 32 | Is it raining? | BodyQuestion | 01/01/2016 | 2 | 1 | 1 | 45
| 1 | 32 | Is it raining? | BodyQuestion | 01/01/2016 | 2 | 1 | 3 | 67
EDIT 1: Example given.
Try this:
SELECT `ID` , `UserID` , `Title`, `Body`, `Date`, `Likes`, `Unlikes`, `AnswerID`, `AnswerUserID`
FROM QUESTIONS q
INNER JOIN ANSWERS a ON q.`ID` = a.`QuestionID`
INNER JOIN QuestionVotes v ON q.`ID` = v.`QuestionID`
I've the following table:
| id | Name | Date of Birth | Date of Death | Result |
| 1 | John | 3546565 | 3548987 | |
| 2 | Mary | 5233654 | 5265458 | |
| 3 | Lewis| 6546876 | 6548752 | |
| 4 | Mark | 6546546 | 6767767 | |
| 5 | Steve| 6546877 | 6548798 | |
And I need to do this for the whole table:
Result = 1, if( current_row(Date of Birth) - row_above_current_row(Date of Death))>X else 0
To make things easier, I guess, I created the same table above but with 2 extra id fields: id_minus_one and id_plus_one
Like this:
| id | id_minus_one | id_plus_one |Name | Date_of_Birth | Date_of_Death | Result |
| 1 | 0 | 2 |John | 3546565 | 3548987 | |
| 2 | 1 | 3 |Mary | 5233654 | 5265458 | |
| 3 | 2 | 4 |Lewis| 6546876 | 6548752 | |
| 4 | 3 | 5 |Mark | 6546546 | 6767767 | |
| 5 | 4 | 6 |Steve| 6546877 | 6548798 | |
So my approach would be something like (in pseudo code):
for id=1, ignore result. (Because there is no row above)
for id=2, Result = 1 if( (Where id=2).Date_of_Birth - (where id_minus_one=id-1).Date_of_Death )>X else 0
for id=3, Result = 1 if( (Where id=3).Date_of_Birth - (where id_minus_one=id-1).Date_of_Death)>X else 0
and so on for the whole table...
Just ignore id_plus_one if there is no need for it, I'll use it later for the same thing. So, if I manage to do this for id_minus_one I'll manage for id_plus_one as they are the same algorithm.
My question is how to pass that pseudo code into SQL code, I can't find a way to relate both ids in just one select.
Thank you!
As you describe this, it is just a self join with some logic on the select:
select t.*,
((t.date_of_birth - tprev.date_of_death) > x) as flag
from t left outer join
t tprev
on t.id_minus_one = tprev.id
I'm relatively new to MySQL and have come across a problem to which I cannot seem to find a solution. I have searched but could not find an answer. I'm open to the possibility that I'm not asking the question correctly. Here goes:
I'm trying to use the name of a given column and the values within that column from one table to pull values from another table. The first table contains 3 columns with the response codified. The second table contains the definitions for each code for each item. The same number code is associated with different meanings depending on the item. For example:
table1 (this table cannot change):
--------------------------------------------------------------
|result_id | f_initial | l_name | item_A | item_B | item_C |
--------------------------------------------------------------
| 1 | j | doe | 1 | 3 | 2 |
| 2 | k | smith | 3 | 1 | 2 |
| 3 | l | williams | 2 | 2 | 1 |
--------------------------------------------------------------
table2 (this table can be modified, split, or whatever needs to be done):
-------------------------------------------
|item_id | item_name | score | definition |
-------------------------------------------
| 1 | item_A | 1 | agree |
| 2 | item_A | 2 | neutral |
| 3 | item_A | 3 | disagree |
| 4 | item_B | 1 | likely |
| 5 | item_B | 2 | not likely |
| 6 | item_B | 3 | no reply |
| 7 | item_C | 1 | yes |
| 8 | item_C | 2 | no |
-------------------------------------------
My goal is for the query to output the following:
--------------------------------------------------------------------
|result_id | f_initial | l_name | item_A | item_B | item_C |
--------------------------------------------------------------------
| 1 | j | doe | agree | no reply | no |
| 2 | k | smith | disagree | likely | no |
| 3 | l | williams | neutral | not likely | yes |
--------------------------------------------------------------------
Any assistance or guidance is greatly appreciated. Thank you in advance.
You must join the two tables on the item_A/B/C and score columns
select t1.result_id, t1.f_initial, t1.l_name,
t2a.definition as item_a,
t2b.definition as item_b,
t2c.definition as item_c
from table1 t1
join table2 t2a on t2a.score = t1.item_a
join table2 t2b on t2b.score = t1.item_b
join table2 t2c on t2c.score = t1.item_c
where t2a.item_name = 'item_A'
and t2b.item_name = 'item_B'
and t2c.item_name = 'item_C'