PHP: Concatenating database results by email - php

I have a list of tasks assigned to multiple users. I'd like to set up a cron job and send out email notifications once an hour to each user. Here's my query:
SELECT t.*, u.name, u.email
FROM tasks t, users u
WHERE t.date_created > DATE_SUB(NOW(), INTERVAL 1 HOUR) AND t.user_id = u.id
ORDER BY t.date_created ASC
Here's the result (I trimmed a few columns to fit better):
+----+-------+---------------------+---------+--------+------+--------------+
| id | title | date_created | user_id | status | name | email |
+----+-------+---------------------+---------+--------+------+--------------+
| 9 | task1 | 2013-09-01 17:56:10 | 2 | active | John | js#gmail.com |
| 10 | task2 | 2013-09-01 17:57:20 | 1 | active | Tim | ti#gmail.com |
| 11 | task3 | 2013-09-01 17:58:30 | 2 | active | John | js#gmail.com |
| 12 | task4 | 2013-09-01 17:59:40 | 1 | active | Tim | ti#gmail.com |
+----+-------+---------------------+---------+--------+------+--------------+
The problem is that I can't figure out how to concatenate the tasks belonging to a certain user_id and then send them out to the assigned email. So for the above example there would be two emails sent out:
task1 and task 3 (to js#gmail.com)
task2 and task 4 (to ti#gmail.com)

Try with the GROUP_CONCAT aggregate command :
SELECT GROUP_CONCAT(t.title), u.name, u.email
FROM tasks t, users u
WHERE t.date_created > DATE_SUB(NOW(), INTERVAL 1 HOUR) AND t.user_id = u.id
GROUP BY u.id
This will output something like :
task1,task3 | John | js#gmail.com
task2,task4 | Tim | ti#gmail.com
Default is a comma delimited string, but you can specify another separator like this : GROUP_CONCAT(t.title,' and ')

Related

GROUP BY multiple conditions at once

I have a tables like this:
Users
+----+----------+-------------+
| id | name | other_stuff |
+----+----------+-------------+
| 1 | John Doe | x |
| 2 | Jane Doe | y |
| 3 | Burt Olm | z |
+----+----------+-------------+
Places
+----+------------+-------------+
| id | name | other_stuff |
+----+------------+-------------+
| 1 | Building A | x |
| 2 | Building B | y |
+----+------------+-------------+
Subjects
+----+------------+-------------+
| id | name | other_stuff |
+----+------------+-------------+
| 1 | Math | x |
| 2 | English | y |
+----+------------+-------------+
And a joining table:
PastLectures = lectures that took place
+----+-----------+----------+------------+---------+------------+
| id | id_users | id_place | id_subjects| length | date |
+----+-----------+----------+------------+---------+------------+
| 1 | 1 | 1 | 1 | 60 | 2015-10-25 |
| 2 | 1 | 1 | 1 | 120 | 2015-11-06 |
| 3 | 2 | 2 | 2 | 120 | 2015-11-04 |
| 4 | 2 | 2 | 1 | 60 | 2015-11-10 |
| 5 | 1 | 2 | 1 | 60 | 2015-11-10 |
| 6 | 2 | 2 | 1 | 40 | 2015-11-15 |
| 7 | 1 | 2 | 2 | 30 | 2015-11-15 |
+----+-----------+----------+------------+---------+------------+
I would like to display SUM of all lessons for each user for given month. The SUM should by grouped by each Places and Subjects.
The result in final PHP output should look like this:
November 2015
+------------+-------------+---------------+-------------+
| Users.name | Places.name | Subjects.name | sum(length) |
+------------+-------------+---------------+-------------+
| Burt Olm | - | - | - |
| Jane Doe | Building B | Math | 100 |
| = | = | English | 120 |
| John Doe | Building A | Math | 120 |
| = | Building B | Math | 60 |
| = | = | English | 30 |
+------------+-------------+---------------+-------------+
I have tried creating the full output in pure SQL query using multiple GROUP BY (Group by - multiple conditions - MySQL), but when I do GROUP BY User.id,Places.id it shows each user only once (3 results) no matter the other GROUP BY conditions.
SQL:
SELECT PastLectures.id_users,Users.name AS user,Places.name AS places,Subjects.name AS subjects
FROM PastLectures
LEFT JOIN Users ON PastLectures.id_users = Users.id
LEFT JOIN Places ON PastLectures.id_Places = Places.id
LEFT JOIN Subjects ON PastLectures.id_Subjects = Subjects.id
WHERE date >= \''.$monthStart->format('Y-m-d H:i:s').'\' AND date <= \''.$monthEnd->format('Y-m-d H:i:s').'\'
GROUP BY Users.id,Places.id
ORDER BY Users.name,Places.name,Subjects.name
But I don't mind if part of the solution is done in PHP, I just don't know what to do next.
EDIT:
I also have a table Timetable, that stores who regularly teaches what and where. It stores only used combinations of the tables (each valid combination once).
Timetable = lectures that regularly take place
+----+-----------+----------+------------+-------------+
| id | id_users | id_place | id_subjects| other_stuff |
+----+-----------+----------+------------+-------------+
| 1 | 1 | 1 | 1 | x |
| 2 | 1 | 2 | 1 | y |
| 3 | 1 | 2 | 2 | z |
| 4 | 2 | 2 | 1 | a |
| 5 | 2 | 2 | 2 | b |
+----+-----------+----------+------------+-------------+
Is it possible to add only users with combinations that have a row in this table?
In this case it would mean omitting Burt Olm (no id=3 in Timetable). But if Burt has a Timetable entry and still no PastLectures entry, he would show here as in sample result (he should have had a lecture that month, because he is in Timetable, but no lectures took place).
Based on #Barmar's solution I updated the final SQL by making Timetable a primary table and adding one more LEFT JOIN to suffice those needs.
Final SQL:
SELECT Users.name AS user,Places.name AS places,Subjects.name AS subjects, SUM(PastLectures.length)
FROM Timetable
LEFT JOIN PastLectures ON PastLectures.id_users = Timetable.id_users AND PastLectures.id_place = Timetable.id_place AND PastLectures.id_subjects = Timetable.id_subjects
AND date BETWEEN '2015-11-01 00:00:00' AND '2015-11-30 23:59:59'
LEFT JOIN Places ON Timetable.id_Place = Places.id
LEFT JOIN Subjects ON Timetable.id_Subjects = Subjects.id
LEFT JOIN Users ON Timetable.id_users = Users.id
GROUP BY Timetable.id,Timetable.id_users,Timetable.id_Place,Timetable.id_Subjects
ORDER BY Users.name,Places.name,Subjects.name
You need to include Subjects.id in the GROUP BY, so you get a separate result for each subject.
Also, you shouldn't use columns in tables that are joined with LEFT JOIN in the GROUP BY column. If you do that, all the non-matching rows will be grouped together, because they all have NULL in that column. Use the columns in the main table.
GROUP BY PastLectures.id_users, PastLectures.id_Place, PastLectures.id_Subjects
DEMO
Note that there's no row for Burt Olm in the demo output, because all his rows are filtered out by the WHERE clause. If you want all users to be shown, you should make Users the main table, not PastLectures. And the date criteria needs to be moved into the ON clause when joining with PastLectures.
SELECT Users.name AS user,Places.name AS places,Subjects.name AS subjects, SUM(length)
FROM Users
LEFT JOIN PastLectures ON PastLectures.id_users = Users.id
AND date BETWEEN '2015-11-01 00:00:00' AND '2015-11-30 23:59:59'
LEFT JOIN Places ON PastLectures.id_Place = Places.id
LEFT JOIN Subjects ON PastLectures.id_Subjects = Subjects.id
GROUP BY Users.id, PastLectures.id_Place, PastLectures.id_Subjects
ORDER BY Users.name,Places.name,Subjects.name
DEMO
According to standard SQL, you should GROUP BY all the fields you select, except for the aggregated fields (like sum). Althought MySql allows to do otherwise, when it can be done adhering to the standards, it is better to do so (who knows when you need to port your code to another database engine). So write your SQL like this:
SELECT PastLectures.id_users,
Users.name AS user,
Places.name AS places,
Subjects.name AS subjects,
Sum(length)
FROM PastLectures
LEFT JOIN Users ON PastLectures.id_users = Users.id
LEFT JOIN Places ON PastLectures.id_Places = Places.id
LEFT JOIN Subjects ON PastLectures.id_Subjects = Subjects.id
WHERE date BETWEEN \''.$monthStart->format('Y-m-d H:i:s').'\'
AND \''.$monthEnd->format('Y-m-d H:i:s').'\'
GROUP BY PastLectures.id_users,
Users.name,
Places.name,
Subjects.name
ORDER BY Users.name,
Places.name,
Subjects.name

How to get a value from MySQL n days before from CURDATE()

I want to join 4 tables to list all the values from a table those have the duration from last updated to current date is more that the duration in other table, table are given below (my English not good to understand so am explaining with examble)
first table daily_tasks
+---------+---------+
| task_id | type_id |
+---------+---------+
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
+---------+---------+
Second Table daily_task_report
+-----------+---------+------------+
| report_id | task_id | task_date |
+-----------+---------+------------+
| 1 | 1 | 2015-09-10 |
| 2 | 3 | 2015-09-10 |
| 3 | 1 | 2015-09-11 |
| 4 | 3 | 2015-09-16 |
+-----------+---------+------------+
Third Table duration_types
+---------+---------------+------------------------+
| type_id | duration_type | duration_time(in days) |
+---------+---------------+------------------------+
| 1 | Daily Task | 1 |
| 2 | Weekly Task | 6 |
| 3 | Monthly Task | 26 |
| 4 | Yearly Task | 313 |
+---------+---------------+------------------------+
Fourth Table calendar
+--------+------------+---------+
| cal_id | cal_date | holiday |
+--------+------------+---------+
| 1 | 2015-09-10 | 0 |
| 2 | 2015-09-11 | 0 |
| 3 | 2015-09-12 | 0 |
| 4 | 2015-09-13 | 1 |
+--------+------------+---------+
Here daily_tasks.type_id is from duration_types.type_id and daily_task_report.task_id is from daily_tasks.task_id. I want to select all the task_id those task_date and current_date difference will greater than duration_time, also while calculating the duration i have to avoid the dates those have holiday=1 from calendar.
I tried queries but not proper, i got the values without including the calendar table, but that not a good way, query is taking more time to execute.
"SELECT dailyTasks.task_id FROM
(SELECT tab.* FROM (SELECT
tasks.task_type,report.*
FROM daily_tasks AS tasks
LEFT JOIN daily_task_reports AS report ON tasks.task_id=report.task_id
WHERE 1 ORDER BY report.task_date DESC) as tab GROUP BY tab.d_task_id) AS dailyTasks
LEFT JOIN duration_types AS type ON dailyTasks.task_type=type.type_id
WHERE DATEDIFF(CURDATE(),dailyTasks.task_date)>=type.duration_time"
Please someone help, I stuck in this section
According to given table You have some unexpected text or unknown columns in your query
Try this query
"SELECT dailyTasks.d_task_id FROM
(SELECT tab.* FROM
(SELECT tasks.type_id,report.* FROM daily_tasks AS tasks
LEFT JOIN daily_task_reports AS report ON tasks.task_id=report.task_id
ORDER BY report.task_date DESC)
as tab GROUP BY tab.task_id) AS dailyTasks
LEFT JOIN duration_types AS type ON dailyTasks.type_id=type.type_id
WHERE DATEDIFF(CURDATE(),dailyTasks.task_date)>=type.duration_time"
It can be also works in single query
SELECT tasks.task_id FROM daily_tasks AS tasks
LEFT JOIN daily_task_reports AS report ON tasks.task_id=report.task_id
LEFT JOIN duration_types AS type ON tasks.type_id = type.type_id and DATEDIFF(CURDATE(),report.task_date) >= type.duration_time
*I tried but not exclude that id which have holiday in calendar
You can create it on your coding side I gave you new query included with calendar
*
SELECT tasks.task_id,report.task_date,calendar.holiday FROM daily_tasks AS tasks
LEFT JOIN daily_task_reports AS report ON tasks.task_id=report.task_id
LEFT JOIN duration_types AS type ON tasks.type_id = type.type_id and DATEDIFF(CURDATE(),report.task_date) >= type.duration_time
LEFT JOIN calendar ON report.task_date=calendar.cal_date
where calendar.holiday = '0'
order By report.task_date desc

Select values from another table with most recent entry

I have 2 MySQL Tables:
Table with all Events
+----+---------------------+
| id | Eventtitle |
+----+---------------------+
| 1 | Event 1 |
| 2 | Event 2 |
| 3 | Event 3 |
| 4 | Event 4 |
+----+---------------------+
Table with user attend statuses - Users can change their status multiple times. Every time they change it, a new entry is inserted into the table
+----+------------+----------+---------+---------------------+
| id | event_id | user_id | status | attend_time |
+----+------------+----------+---------+---------------------+
| 1 | 1 | 2 | 1 |2013-07-03 15:34:02 |
| 2 | 1 | 2 | 2 |2013-08-03 19:01:02 | <--
| 3 | 3 | 1 | 1 |2013-07-03 15:34:02 |
| 4 | 4 | 4 | 3 |2013-07-03 15:34:02 |
| 5 | 4 | 6 | 2 |2013-07-03 15:34:02 |
| 6 | 4 | 6 | 1 |2013-07-03 18:55:02 | <--
+----+-----------------------+---------+---------------------+
Now I want all events listed and additionally the most recent attend state and attend_time of the currently logged in user (for example user_id 2 oder 54) - IF he is not in the attend table i still need an entry of the event. (in that case a NULL for the state and attend_time would be good)
Here I rebuild the Data Structure: http://sqlfiddle.com/#!2/c1b3f
IF there is no way on how to get the result with MySQL - I will try to get it with PHP
Try something like this:
SELECT s.id, eventtitle, status, attend_time
FROM events e
JOIN status s ON e.id = s.event_id
WHERE user_id = 2 AND attend_time = (SELECT MAX(attend_time) FROM status
WHERE user_id = 2)
SQLFiddle
Or:
SELECT s.id, eventtitle, s.status, s.attend_time
FROM events e
JOIN status s ON e.id = s.event_id
LEFT JOIN status s2 ON s.attend_time < s2.attend_time
WHERE s.user_id = 2 AND s2.attend_time IS NULL
SQLFiddle
(not tested)
SELECT a.id, eventtitle, status, attend_time FROM events b JOIN status a ON b.id = a.event_id WHERE user_id = 2 order by attend_time desc

MySQL Sum multiple column values with conditions

I have the following schema (two tables):
**APPS**
| ID (bigint) | USERID (Bigint) | USAGE_START_TIME (datetime) |
------------------------------------------------------------------
| 1 | 12 | 2013-05-03 04:42:55 |
| 2 | 12 | 2013-05-12 06:22:45 |
| 3 | 12 | 2013-06-12 08:44:24 |
| 4 | 12 | 2013-06-24 04:20:56 |
| 5 | 13 | 2013-06-26 08:20:26 |
| 6 | 13 | 2013-09-12 05:48:27 |
**USAGE**
| ID (bigint) | APPID (bigint) | DEVICEID (bigint) | HIGH_COUNT (bigint) | MEDIUM_COUNT (bigint) |
--------------------------------------------------------------------------------------------------------
| 1 | 1 | 2 | 400 | 200 |
| 2 | 1 | 3 | 200 | 100 |
| 3 | 2 | 3 | 350 | 40 |
| 4 | 3 | 4 | 2 | 400 |
| 5 | 4 | 2 | 4 | 30 |
| 6 | 5 | 3 | 50 | 300 |
Explanation:
So, there are two tables.
Now I want to find the following:
Given a USERID, Get sum of HIGH_COUNT & MEDIUM_COUNT. While counting
the SUM it should be taken care that: If in USAGE, same device is used
more than once, then the record which has the latest info (based on
APPS.USAGE_START_TIME), should be considered while calculating the
sum.
For ex:
For above schema, result should be (for userid=12) :
| HIGH_COUNT (bigint) | MEDIUM_COUNT (Bigint) |
-----------------------------------------------
| 356 | 470 |
SQL Fiddle: http://sqlfiddle.com/#!2/74ae0f
If a user uses multiple APPS on one device, this query will use the APPS row with the highest usage_start_time:
select a.userid
, sum(u.high_count)
, sum(u.medium_count)
from apps a
join `usage` u
on u.appid = a.id
join (
select u.device_id
, a.userid
, max(a.usage_start_time) as max_start_time
from apps a
join `usage` u
on u.appid = a.id
group by
u.device_id
, a.userid
) filter
on filter.device_id = u.device_id
and filter.userid = a.userid
and filter.max_start_time = a.usage_start_time
group by
a.userid
In your dataset, it will select usage rows 5, 3, 4 for user 12.
See it working at SQL Fiddle.
I can't quite get your numbers, but something like this should work...
SELECT a.userid
, SUM(u.high_count)
, SUM(u.medium_count)
FROM apps a
JOIN `usage` u
ON u.appid = a.id
JOIN
( SELECT userid
, deviceid
, MAX(usage_start_time) max_usage_start_time
FROM apps a
JOIN `usage` u
ON u.appid = a.id
GROUP
BY userid
, deviceid
) x
ON x.userid = a.userid
AND x.deviceid = u.deviceid
AND x.max_usage_start_time = a.usage_start_time
GROUP
BY userid;
Note that usage is a reserved word. Therefore, this is a bad name for a column (or a table). Also, note inconsistencies between your question and your fiddle.
I think not had chance to test it but
SELECT SUM(HIGH_COUNT), SUM(MEDIUM_COUNT) FROM `USAGE` INNER JOIN `APPS` ON USAGE.APPID=APPS.ID WHERE APPS.USERID=$input_user_id_to_lookup
will give you your counts.
For yoru other question (homework?) you didn't give us the full schema so we can't guess what you need doing.
Also whoever designed that db should be shot its horrible

Getting the last row in each group by?

Hello basically im trying to copy the messaging system that facebook has onto my site.
This is the logic...
"When a user1 CREATES A NEW MESSAGE to send to user7, A new thread is created with thread_id of 1(table: messages_thread) and a new entry is inserted into table:messages which is message_id 1(table:messages). When user7 REPLYS to user1's message, message2 is created, and it has a thread_id of 1.
Now when user 1 CREATES A NEW MESSAGE to sent to user7 thread 2 is created, and message 3 is created. When user7 replies to thread2, message 4 is created (hopefully you get the logic.)
Everything is fine. the only problem is i need to select the newest message in the thread but im having trouble with the sql,
This sql that I have as of right now...
SELECT max(message_id) message_id, m.thread_id, m.body, m.user_id,m.to_id, m.message_status, m.new, m.date, u.id, u.displayname, u.username, u.profile_img
FROM messages m INNER JOIN users u ON u.id = m.user_id
WHERE to_id = 7 AND (message_status = 'unread' or message_status='read' or message_status='saved')
group by thread_id Order by message_id Desc LIMIT 10
Produces this...
+------------+-----------+----------------------+---------+-------+----------------+-----+------------+----+--------------+----------+-------------+
| message_id | thread_id | body | user_id | to_id | message_status | new | date | id | displayname | username | profile_img |
+------------+-----------+----------------------+---------+-------+----------------+-----+------------+----+--------------+----------+-------------+
| 6 | 2 | Really nice | 1 | 7 | read | 0 | 1298617367 | 1 | Kenny Blake | imkenee | 28_1 |
| 4 | 1 | Whats good with you? | 1 | 7 | read | 0 | 1298607438 | 1 | Kenny Blake | imkenee | 28_1 |
+------------+-----------+----------------------+---------+-------+----------------+-----+------------+----+--------------+----------+-------------+
This is good but one small problem, it selects the first row in each group and im trying to select the newest (the last row) in each group
how can i do this? here is the tables. Thanks!
Table: Messages_thread
+----+---------+----------------+-------------+-----------+---------------+-------------+------------+
| id | user_id | subject | from_status | to_status | from_s_delete | to_s_delete | date |
+----+---------+----------------+-------------+-----------+---------------+-------------+------------+
| 1 | 1 | Hey Kenny | unread | unread | 0 | 0 | 1298607438 |
| 2 | 7 | Check out this | unread | unread | 0 | 0 | 1298617344 |
+----+---------+----------------+-------------+-----------+---------------+-------------+------------+
Table Messages
+------------+-----------+---------+-------+-----------------------------------------------------------+----------------+-----------------+-----+------------+
| message_id | thread_id | user_id | to_id | body | message_status | is_sent_deleted | new | date |
+------------+-----------+---------+-------+-----------------------------------------------------------+----------------+-----------------+-----+------------+
| 1 | 1 | 1 | 7 | Whats good with you? | read | 0 | 0 | 1298607438 |
| 2 | 1 | 7 | 1 | Nothing Kenny just chilling. Whats up with you though???? | read | 0 | 0 | 1298607473 |
| 4 | 1 | 1 | 7 | Just posted victor how are you man? | read | 0 | 0 | 1298607956 |
| 5 | 2 | 7 | 1 | Look at this poem.... | read | 0 | 0 | 1298617344 |
| 6 | 2 | 1 | 7 | Really nice | read | 0 | 0 | 1298617367 |
| 7 | 2 | 7 | 1 | Yea i know right :) | unread | 0 | 0 | 1298617383 |
+------------+-----------+---------+-------+-----------------------------------------------------------+----------------+-----------------+-----+------------+
Group the threads in a subquery, which will return the last message for each thread:
SELECT m.message_id, m.thread_id, m.body, m.user_id,
m.to_id, m.message_status, m.new, m.date, u.id, u.displayname, u.username, u.profile_img
FROM messages m
INNER JOIN users u ON u.id = m.user_id
INNER JOIN (
SELECT MAX(message_id) MaxMsgIDForThread
FROM messages
WHERE to_id = 7
AND (message_status = 'unread'
or message_status='read'
or message_status='saved')
GROUP BY thread_id
) g ON m.message_id = g.MaxMsgIDForThread
Order by m.message_id Desc
LIMIT 10
The WHERE may need to be moved to the outer query, right now it will pick the last message the meets the criteria, move it to the outer query if you want to skip the thread entirely if the conditions are not met.
You should also consider storing the message status as a ENUM which will help the comparisons.
There is no way to add order to group by
But maybe this works:
SELECT max(message_id) message_id, MAX(m.thread_id), m.body, m.user_id,m.to_id, m.message_status, m.new, m.date, u.id, u.displayname, u.username, u.profile_img
FROM messages m INNER JOIN users u ON u.id = m.user_id
WHERE to_id = 7 AND (message_status = 'unread' or message_status='read' or message_status='saved')
group by thread_id Order by message_id Desc LIMIT 10

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