mysql query to count - mysql

i am doing sql query to get values from db, db structure as follows...
fcats
| id | title | section |
+----+--------+---------+
| 1 | test | gd |
+----+--------+---------+
ftopics
| id | title | cat_id |
+----+--------+---------+
| 1 | test1 | 1 |
+----+--------+---------+
fposts
| id | post | topic_id |
+----+-------+----------+
| 1 | post | 1 |
+----+-------+----------+
I want to get total number of topics and posts for given category and using following query...
SELECT id, title (SELECT count(id) FROM ftopics WHERE cat_id = id) AS total_topics FROM fcats WHERE section = "gd"
and it gives correct results for total topics but how can i get total number of posts for all categories, i am abit confused about, please help me to write this query. thanks.

try this:
SELECT
t.id,
t.title,
COUNT(f.id) + COUNT(p.id) AS total
FROM fcats t
LEFT OUTER JOIN ftopics f
ON f.cat_id = t.id
LEFT OUTER JOIN fposts p
ON p.cat_id = t.id
WHERE t.section = "gd"
GROUP BY t.id, t.title

SELECT
t.id,
t.title,
COUNT(f.id) AS total_topics,
(SELECT COUNT(p.id) FROM fposts WHERE topic_id = t.id) total_posts
FROM fcats t
INNER JOIN ftopics f
ON f.cat_id = t.id
WHERE t.section = "gd"
GROUP BY t.id, t.title
not sure if this is the right syntax, updated the other answers code to try to answer your request for the two totals.

Related

SQL - Join multiple tables and count()

I am trying to count the number of results in a column after joining a table and I am having a hard time getting my query to work.
In the end result, I need to get a table with the product id, product name and the number of medias for each product.
This is what I have so far:
SQL
select
p.id,
p.name,
count(distinct mp.media_id)
from products as p
left join medias_products as mp
on mp.product_id = p.id
group by mp.media_id
order by p.id
These are the tables:
Medias
Id | client id
------ | ---------
1 | 1
2 | 2
Products
id | name | client_id
------ | -------- | ---------
1 | product1 | 1
2 | product2 | 2
medias_products
product_id | media_id
---------- | --------
1 | 2
2 | 1
Client
id | name
------ | -----
1 | Peter
2 | John
In addition, I'd like to find another query that would give me the results filtered by an specific client id.
Can someone please shed some light and share the knowledge.
Thanks in advance.
Try this:
select
p.id,
min(p.name) as name,
count(distinct mp.media_id) as medias
from products as p
left join medias_products as mp
on mp.product_id = p.id
group by p.id
order by p.id
For your second query:
select
p.id,
min(p.name) as name,
count(distinct mp.media_id) as medias
from products as p
inner join medias_products as mp
on mp.product_id = p.id
inner join medias as m
on m.id = mp.media_id
inner join clients as c
on c.id = m.client_id
where c.id = <your client's id>
group by p.id
order by p.id
Shouldn't you GROUP BY p.id instead of mp.media_id? That is
select
p.id,
p.name,
count(distinct mp.media_id)
from
products as p
left join medias_products as mp
on p.id = mp.product_id
group by p.id
order by p.id

adding different columns in same table usin inner join in mysql

I want to make a report of time entry of particular projects. I tried below query.
Table1: Projects
id | Name
------------
1 | A
2 | B
Table2: EmployeeTimeEntry
proj | activity |time
----------------------
1 | coding | 5
2 | coding | 2
1 | testing | 2
1 | coding | 2
My desired Outpput for proj A:
proj | TotalDur | activity | Activitytime
--------------------------------------------
A | 9 | coding | 7
A | 9 | testing | 2
My Query :
$query = "SELECT
name as 'Proj',
TimeEntry.Total as 'TotalDur',
ATimeEntry.ADetails as 'activity',
ATimeEntry.ATotal as 'Activitytime'
FROM Projects pr
INNER JOIN(SELECT project,SUM(time) as Total from EmployeeTimeEntry group by project ) TimeEntry on pr.id = TimeEntry.project
INNER JOIN(SELECT project,details as ADetails,SUM(time) as ATotal from EmployeeTimeEntry where id = pr.id group by details ) ATimeEntry on pr.id = TimeEntry.project";
But i got output as
proj | TotalDur | activity | Activitytime
--------------------------------------------
A | 9 | coding | 9
A | 9 | testing | 2
All activity times for all projects get added .
I use combobo to select which projects to show the report.
I think you are over complicating it
select
p.name as Proj,
x.TotalDur,
et.activity,
sum(et.time) as Activitytime
from Projects p
join (
select proj, sum(time) as TotalDur from EmployeeTimeEntry group by proj
)x on x.proj = p.id
join EmployeeTimeEntry et on et.proj = p.id
where p.name = 'A'
group by p.name,et.activity
DEMO
Maybe this is what you want?
select
p.Name as Proj,
(select sum(time) as TotalDur from EmployeeTimeEntry where proj = p.id group by proj) TotalDur,
activity,
sum(e.time) as ActivityTime
from Projects p
inner join EmployeeTimeEntry e on e.proj = p.id
where p.Name = 'A'
group by name, activity, p.id
Sample SQL Fiddle

Strange order of results when adding joins

I'm trying to build a commenting system on my website but having issues with ordering the comments correctly. This is a screenshot of what I had before it went wrong:
And this is the query before it went wrong:
SELECT
com.comment_id,
com.parent_id,
com.is_reply,
com.user_id,
com.comment,
com.posted,
usr.username
FROM
blog_comments AS com
LEFT JOIN
users AS usr ON com.user_id = usr.user_id
WHERE
com.article_id = :article_id AND com.moderated = 1 AND com.status = 1
ORDER BY
com.parent_id DESC;
I now want to include each comment's votes from my blog_comment_votes table, using a LEFT OUTER JOIN, and came up with this query, which works, but screws with the order of results:
SELECT
com.comment_id,
com.parent_id,
com.is_reply,
com.user_id,
com.comment,
com.posted,
usr.username,
IFNULL(c.cnt,0) votes
FROM
blog_comments AS com
LEFT JOIN
users AS usr ON com.user_id = usr.user_id
LEFT OUTER JOIN (
SELECT comment_id, COUNT(vote_id) as cnt
FROM blog_comment_votes
GROUP BY comment_id) c
ON com.comment_id = c.comment_id
WHERE
com.article_id = :article_id AND com.moderated = 1 AND com.status = 1
ORDER BY
com.parent_id DESC;
I now get this order, which is bizarre:
I tried adding a GROUP BY clause on com.comment_id but that failed too. I can't understand how adding a simple join can alter the order of results! Can anybody help back on the correct path?
EXAMPLE TABLE DATA AND EXPECTED RESULTS
These are my relevant tables with example data:
[users]
user_id | username
--------|-----------------
1 | PaparazzoKid
[blog_comments]
comment_id | parent_id | is_reply | article_id | user_id | comment
-----------|-----------|----------|------------|---------|---------------------------
1 | 1 | | 1 | 1 | First comment
2 | 2 | 1 | 1 | 20 | Reply to first comment
3 | 3 | | 1 | 391 | Second comment
[blog_comment_votes]
vote_id | comment_id | article_id | user_id
--------|------------|------------|--------------
1 | 2 | 1 | 233
2 | 2 | 1 | 122
So the order should be
First comment
Reply to first comment +2
Second Comment
It's difficult to say without looking at your query results, but my guess is that it's because you are only ordering by parent id and not saying how to order when two records have the same parent id. Try changing your query to look like this:
SELECT
com.comment_id,
com.parent_id,
com.is_reply,
com.user_id,
com.comment,
com.posted,
usr.username,
COUNT(c.votes) votes
FROM
blog_comments AS com
LEFT JOIN
users AS usr ON com.user_id = usr.user_id
LEFT JOIN
blog_comment_votes c ON com.comment_id = c.comment_id
WHERE
com.article_id = :article_id AND com.moderated = 1 AND com.status = 1
GROUP BY
com.comment_id,
com.parent_id,
com.is_reply,
com.user_id,
com.comment,
com.posted,
usr.username
ORDER BY
com.parent_id DESC, com.comment_id;

MySQL syntax issue, multiple SELECT statements

I am working of a project that has 2 tables as follows: users_fb and posts
I spent 3 hours playing with the code and then I gave up.
table: posts
+-----+---------+---------+---------+---------+-----------+
| id | by_user | by_page | votes | status | time |
+-----+---------+---------+---------+---------+-----------+
| 1 | 1 | 0 | 20 | 1 | 372041014 |
+-----+---------+---------+---------+---------+-----------+
table: users_fb
+-----+-----------+-------+---------+--------+-------+
| id | username | name | gender | fb_id | email |
+-----+-----------+-------+---------+--------+-------+
SELECT username,
(
SELECT COUNT(b.by_user)
FROM users_fb a LEFT JOIN posts b ON a.id = b.by_user
WHERE b.by_page = '0'
GROUP BY a.username
) AS totalCount ,
(
SELECT IFNULL(SUM(b.votes),0)
FROM users_fb a LEFT JOIN posts b ON a.id = b.by_user
GROUP BY users_fb.id
) AS total_votes
FROM users_fb ORDER BY total_votes DESC
The desired output
+-------------------+-------------+-------------+
| username | totalCount | total_votes |
+-------------------+-------------+-------------+
| user4 | 1 | 25 |
| user1 | 0 | 0 |
| user2 | 0 | 0 |
| user3 | 0 | 0 |
+-------------------+-------------+-------------+
UNFORTUNATELY: This is what I am getting
+-------------------+-------------+-------------+
| username | totalCount | total_votes |
+-------------------+-------------+-------------+
| user4 | 1 | 25 |
| user1 | 1 | 25 |
| user2 | 1 | 25 |
| user3 | 1 | 25 |
+-------------------+-------------+-------------+
If you need any further information, let me know. Thanks for your help.
You don't appear to have anything to join your tables together to match up with posts / votes go with which user.
Something like this should do it
SELECT users_fb.username, Sub1.postcount, Sub2.votecount
FROM users_fb
LEFT OUTER JOIN(
SELECT a.username, COUNT(*) AS postcount
FROM users_fb a
INNER JOIN posts b
ON a.id = b.by_user
WHERE b.by_page = '0'
GROUP BY a.username
) Sub1
ON users_fb.username = Sub1.username
LEFT OUTER JOIN(
SELECT users_fb.id, IFNULL(SUM(b.votes),0) AS votecount
FROM users_fb a
LEFT JOIN posts b
ON a.id = b.by_user
GROUP BY users_fb.id
) Sub2
ON users_fb.id = Sub2.id
Possibly simplified to
SELECT a.username, SUM(IF(b.by_page = '0', 1, 0)) AS postcount, IFNULL(SUM(b.votes),0) AS votecount
FROM users_fb a
LEFT JOIN posts b
ON a.id = b.by_user
GROUP BY a.username
Since you are doing no matching of the selects (i.e. there is no binding WHERE between them), MySQL has no wait to make them show together.
You should do something like this:
SELECT username, totalCount.count, total_votesGROUPED.sum
FROM users_fb
LEFT JOIN (
SELECT COUNT(b.by_user) as count, a.username
FROM users_fb a LEFT JOIN posts b ON a.id = b.by_user
WHERE b.by_page = '0'
GROUP BY a.username
) AS totalCount ON totalCount.username = users_fb.username,
(
SELECT IFNULL(SUM(b.votes),0) as sum, id
FROM users_fb a LEFT JOIN posts b ON a.id = b.by_user
GROUP BY users_fb.id
) AS total_votesGROUPED ON total_votesGROUPED.id = users_fb.id
ORDER BY total_votes DESC
If I had a bit more information, I could test it
Quite a few problems, the biggest is that you don't make any join between your "main query" and your "subqueries".
So finally, something like that should be better.
SELECT
a.username,
SUM (CASE WHEN b.by_page IS NOT NULL and b.by_page = '0' then 1 else 0 end) as cnt,
SUM (IFNULL(b.votes),0) as nbVotes,
FROM users_fb a
LEFT JOIN posts b ON a.id = b.by_user
GROUP BY users_fb.id
SELECT a.username,
COUNT(b.by_user) totalCount,
SUM(IFNULL(b.votes,0)) total_votes
FROM users_fb a
LEFT JOIN posts b
ON a.id = b.by_user
WHERE b.by_page = '0'
GROUP BY a.id,a.username
SELECT username, IFNULL(COUNT(b.by_user), 0) totalCount, IFNULL(SUM(c.votes), 0) total_votes
FROM users_fb a
LEFT JOIN posts b
ON a.id = b.by_user AND b.by_page = 0
LEFT JOIN posts c
ON a.id = b.by_user
GROUP BY username
SQLFIDDLE

how to join 3 tables, topic, comment and user

I have 3 tables, tbl_topic, tbl_comment, tbl_user.
I want to select all the topics created by the user and also the topics that he commented on even if he is not the creator. Here is my database:
tbl_topic
----------
topic_id
topic_title
user_id
tbl_comment
----------
comment_id
comment_message
user_id
topic_id
tbl_user
----------
user_id
user_name
Need it so badly. Thanks!
So far i got this
select * from tbl_topic T inner join tbl_comment C on T.topic_id = C.topic_id inner join tbl_user U on T.user_id = U.user_id GROUP BY T.topic_id
My problem is it only returns the topics that has comments on it. I want to include the topics created by the user even if it has 0 comments.
I want the result to be like this:
+-----------+-----------+----------+-------------+----------------+----------+-------
| topic_id | topic_title | user_id | comment_id | comment_message | user_id | topic_id |
+-----------+-----------+----------+-------------+----------------+----------+--------
| 1 | my topic | 1 | 1 | comment me | 1 | 1
| 2 | others | 2 | 2 | comment me | 1 | 2
| 3 | my nocoment| 1 | NULL | NULL | NULL | NULL
+-----------+---------+--------+-------------+----------+----------+---------+--------
----------+-----------+
user_id | user_name |
-----------+-----------
1 | me |
2 | someone |
1 | me
-----------+---------+--
I messed up with my fields in my tables, the user_id beside comment_message should be comment_user_id but i already created my database that way. Can you help make this possible?
The query below uses UNION in the subquery. The first SELECT gets all topics created by user. The second SELECT statement gets all comments of the user and joins it to table tbl_topic so we can get the topic_title.
SELECT topic_ID, topic_title
FROM
(
SELECT a.user_ID, b.topic_ID, b.topic_title
FROM tbl_user a
INNER JOIN tbl_topic b
ON a.user_ID = b.user_ID
UNION
SELECT a.user_ID, c.topic_ID, c.topic_title
FROM tbl_user a
INNER JOIN tbl_comment b
ON a.user_ID = b.user_ID
INNER JOIN tbl_topic c
ON b.topic_ID = c.topic_ID
) x
WHERE x.user_ID = ?
Try the query below. This will show all the fields.
SELECT tt.*, tc.*, tbl_user.*
FROM tbl_topic AS tt INNER JOIN tbl_comment AS tc ON tt.topic_id = tc.topic_id INNER JOIN tbl_user as tc ON tc.user_id = tu.user_id;
WHERE tu.user_id = x
If you have to filter add to the WHERE clause to the query.
Go with a left join. But there is still a Problem left, you will only get ONE table-comment and ONE user. To get more, you can use the GROUP_CONCAT function, like here: http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
select * from tbl_topic T
LEFT JOIN tbl_comment C on T.topic_id = C.topic_id
LEFT join tbl_user U on T.user_id = U.user_id
WHERE T.user_id = x
GROUP BY T.topic_id
EDIT: the where clause was missing