I'm designing a web based time clock for a school for logging in both students and staff.
I have two tables:
student_time_clock: student_id (foreign key to student), time_stamp, by_adult_id (foreign key to adult)
staff_time_clock: staff_id (foreign key to staff), time_stamp
One of the requirements I've been given is that an observer be able to see the records in one view like the following:
+----------+------------+-------------------------+---------------------+
| In / Out | Time Stamp | Person Logged in or out | Logged in or out by |
+----------+------------+-------------------------+---------------------+
I can do all but the first column with a union. I can't figure out how to get that first column though. Here's the query I'm using for the union:
SELECT stc.entry AS "Time Stamp",
Concat(s.lastname, ",", s.firstname) AS "Punched",
Concat(a.lastname, ",", a.firstname) AS "By"
FROM student_time_clock stc,
student s,
adult a
WHERE stc.student_id = s.id
AND stc.by_adult_id = a.id
UNION
SELECT atc.entry AS "at",
Concat(a.lastname, ",", a.firstname) AS "Staff",
Concat(a.lastname, ",", a.firstname) AS "By"
FROM staff_time_clock atc,
staff s,
adult a
WHERE atc.staff_id = s.id
ORDER BY "time stamp" DESC;
I've tried using a CASE such as:
CASE COUNT( entry ) % 2 WHEN 1 THEN "In" WHEN 0 THEN "Out"
When that case is there though I only get a single row in the result.
Any suggestions? The front end is in PHP but I'd like to create this as a view in the database
I think better to add a flag column in first table to capture the type or entry i.e. "In" or "Out". This can simplify your query with certain result.
Related
I would like to be able to return a single line when the name of some musics are the same or similar, as for example this case:
music with similar names
You can see that the names are the same with an extension like " - JP Ver." or something like that, I would like to be able to group them in one row with the first column incrementing the whole.
My current request to return these lines is as follows:
select count(id) number, name, sec_to_time(floor(sum(duration) / 1000)) time
from track
where user_id = 'value'
group by name, duration
order by number desc, time desc;
I would like to get a result like this
Thank you for reading and responding! I wish you all a good day!
Try:
SELECT COUNT(name) no,
TRIM(SUBSTRING_INDEX(name, '-', 1)) namee
FROM track
GROUP BY namee
Example: https://onecompiler.com/mysql/3xt3bfev6
Use GROUP_CONCAT
Here is a proof of concept script. You can add your other columns. I have grouped by the first 4 letters. You will probably want to use more.
CREATE TABLE track (
idd INT,
nam CHAR(50),
tim INT
);
INSERT INTO track VALUES (1,'Abba 1',5);
INSERT INTO track VALUES (2,'Abba 2',6);
INSERT INTO track VALUES (3,'Beta 1',12);
INSERT INTO track VALUES (4,'Beta 4',8);
SELECT
LEFT(nam,4) AS 'Group',
COUNT(idd) AS 'Number',
GROUP_CONCAT(DISTINCT idd ORDER BY idd ASC SEPARATOR ' & ') AS IDs,
GROUP_CONCAT(DISTINCT nam ORDER BY nam ASC SEPARATOR ', ') AS 'track names',
SUM(tim) AS 'total time'
FROM track
GROUP BY LEFT(nam,4);
DROP TABLE track;
Output
Group Number IDs track names total time
Abba 2 1 & 2 Abba 1, Abba 2 11
Beta 2 3 & 4 Beta 1, Beta 4 20
I have two tables namely register and expressinterest
Where register table contains (user related columns) some are -
i) matri_id (unique but not primary)
ii) mobile
iii) email
iv) last_login
and expressinterest table contains data related to the matches details where columns are namely
i) ei_sender
ii) ei_receiver
iii) ei_response
iv) ei_sent_date
I am comparing the matri_id of register table to ei_sender and ei_receiver of expressinterest table, where one user can send requests to another users and he can receive request from another users.
I have to get the count of Pending, Accepted and Rejected status of all the users present in the register table, but when I am running the query it's running very slow, It takes around 45-60 seconds to fetch only 5000 rows in which the data is not proper (a single ID is coming in 3 rows like Accepted in one row, Rejected in one row and Pending in one row), But I want all the counts to come in a single row like this
r.matri_id | r._email | r.mobile | pending_count | accepted_ count | rejected_count| r.last_login
Some queries which I had tried so far are
select r.matri_id, r.email, r.mobile, r.last_login, e.receiver_response, count(e.receiver_response), e.ei_sender, e.ei_receiver from register r, expressinterest e where r.matri_id = e.ei_sender or r.matri_id = e.ei_receiver GROUP BY e.receiver_response, r.matri_id ORDER BY r.last_login DESC
This is what I want but its taking 5-6 seconds to execute
select matri_id, email, mobile, last_login, (select count(ei_sender) from expressinterest where ei_receiver=matri_id and receiver_response = 'Pending') AS pending_count_mine,
(select count(ei_sender) from expressinterest where ei_sender=matri_id and receiver_response = 'Accepted') AS accepted_count,
(select count(ei_sender) from expressinterest where ei_sender=matri_id and receiver_response = 'Rejected') AS rejected_count FROM register ORDER BY last_login DESC
Thanks
You can replace the multiple correlated subqueries with a single subquery and a left join:
select r.matri_id,
r.email,
r.mobile,
r.last_login,
t.accepted_count,
t.rejected_count,
t.pending_count
from register r
left join (
select ei_sender,
sum(receiver_response = 'Accepted') as accepted_count,
sum(receiver_response = 'Rejected') as rejected_count,
sum(receiver_response = 'Pending') as pending_count
from expressinterest
where receiver_response in ('Rejected', 'Accepted', 'Pending')
group by ei_sender
) t on r.matri_id = t.ei_sender;
I was given a task to show the CPU usage trend as part of a building process which also do regression test.
Each individual test case run has a record in the table RegrCaseResult. The RegrCaseResult table looks something like this:
id projectName ProjectType returnCode startTime endTime totalMetrics
1 'first' 'someType' 16 'someTime' 'someOtherTime' 222
The RegrCaseResult.totalMetrics is a special key which links to another table called ThreadMetrics through ThreadMetrics.id.
Here is how ThreadMetrics will look like:
id componentType componentName cpuTime linkId
1 'Job Totals' 'Job Totals' 'totalTime' 34223
2 'parser1' 'parser1' 'time1' null
3 'parser2' 'generator1' 'time2' null
4 'generator1' 'generator1' 'time3' null
------------------------------------------------------
5 'Job Totals' 'Jot Totals' 'totalTime' 9899
...
The rows with the compnentName 'Job Totals' is what the totalMetrics from RegrCaseResult table will link to and the 'totalTime' is what I am really want to get given a certain projectType. The 'Job Totals' is actually a summation of the other records - in the above example, the summation of time1 through time3. The linkId at the end of table ThreadMetrics can link back to RegrCaseResult.id.
The requirements also states I should have a way to enforce the condition which only includes those projects which have a consistent return code during certain period. That's where my initial question comes from as follows:
I created the following simple table to show what I am trying to achieve:
id projectName returnCode
1 'first' 16
2 'second' 16
3 'third' 8
4 'first' 16
5 'second' 8
6 'first' 16
Basically I want to get all the projects which have a consistent returnCode no matter what the returnCode values are. In the above sample, I should only get one project which is "first". I think this would be simple but I am bad when it comes to database. Any help would be great.
I tried my best to make it clear. Hope I have achieved my goal.
Here is an easy way:
select projectname
from table t
group by projectname
having min(returncode) = max(returncode);
If the min() and max() values are the same, then all the values are the same (unless you have NULL values).
EDIT:
To keep 'third' out, you need some other rule, such as having more than one return code. So, you can do this:
select projectname
from table t
group by projectname
having min(returncode) = max(returncode) and count(*) > 1;
select projectName from projects
group by projectName having count(distinct(returnCode)) = 1)
This would also return projects which has only one entry.
How do you want to handle them?
Working example: http://www.sqlfiddle.com/#!2/e7338/8
This should do it:
SELECT COUNT(ProjectName) AS numCount, ProjectName FROM (
SELECT ProjectName FROM Foo
GROUP BY ProjectName, ReturnCode
) AS Inside
GROUP BY Inside.ProjectName
HAVING numCount = 1
This groups all the ProjectNames by their names and return codes, then selects those that only have a single return code listed.
SQLFiddle Link: http://sqlfiddle.com/#!2/c52b6/11/0
You can try something like this with Not Exists:
Select Distinct ProjectName
From Table A
Where Not Exists
(
Select 1
From Table B
Where B.ProjectName = A.ProjectName
And B.ReturnCode <> A.ReturnCode
)
I'm not sure exactly what you're selecting, so you can change the Select statement to what you need.
I would like to manipulate the result I get from a query.
I have a set of 2.5m rows and there are 10 different ID's for a status. These statusses are not mapped in another table but I would like to manipulate the result I get in SQLyog.
What I would like to do is:
Count(Id) | Status
------------------
500.000 | 1
750.000 | 2
convert into a result
Count(Id) | Status
-------------------
500.000 | Initial order
750.000 | Cancelled
Can this be done in the query? Note that I'm not using PHP or a browser to display the results.
select
count(*) as TotalRecs,
case status
when 1 then "Initial Order"
when 2 then "Cancelled "
when 3 then "whatever "
else "all others "
end case as WordStatus
from
YourTable
group by
2
You can either inline it in a case statement
select COUNT(id),
case status
when 1 then 'initial order'
when 2 then 'cancelled'
# without an else, the rest go to NULL
end status
from tbl
group by status # yes, just on status
Or I would strongly encourage you to create a reference table for this
Tbl Status contains 2 columns ID and Description
select COUNT(tbl.id), status.description
from tbl
LEFT join status on status.id = tbl.status
group by status.description
I am trying to query a database to find the following.
If a customer searches for a hotel in a city between dates A and B, find and return the hotels in which rooms are free between the two dates.
There will be more than one room in each room type (i.e. 5 Rooms in type A, 10 rooms in Type B, etc.) and we have to query the database to find only those hotels in which there is at least one room free in at least one type.
This is my table structure:
**Structure for table 'reservations'**
reservation_id
hotel_id
room_id
customer_id
payment_id
no_of_rooms
check_in_date
check_out_date
reservation_date
**Structure for table 'hotels'**
hotel_id
hotel_name
hotel_description
hotel_address
hotel_location
hotel_country
hotel_city
hotel_type
hotel_stars
hotel_image
hotel_deleted
**Structure for table 'rooms'**
room_id
hotel_id
room_name
max_persons
total_rooms
room_price
room_image
agent_commision
room_facilities
service_tax
vat
city_tax
room_description
room_deleted
And this is my query:
$city_search = '15';
$check_in_date = '29-03-2010';
$check_out_date = '31-03-2010';
$dateFormat_check_in = "DATE_FORMAT('$reservations.check_in_date','%d-%m-%Y')";
$dateFormat_check_out = "DATE_FORMAT('$reservations.check_out_date','%d-%m-%Y')";
$dateCheck = "$dateFormat_check_in >= '$check_in_date' AND $dateFormat_check_out <= '$check_out_date'";
$query = "SELECT $rooms.room_id,
$rooms.room_name,
$rooms.max_persons,
$rooms.room_price,
$hotels.hotel_id,
$hotels.hotel_name,
$hotels.hotel_stars,
$hotels.hotel_type
FROM $hotels,$rooms,$reservations
WHERE $hotels.hotel_city = '$city_search'
AND $hotels.hotel_id = $rooms.hotel_id
AND $hotels.hotel_deleted = '0'
AND $rooms.room_deleted = '0'
AND $rooms.total_rooms - (SELECT SUM($reservations.no_of_rooms) as tot
FROM $reservations
WHERE $dateCheck
GROUP BY $reservations.room_id) > '0'";
The number of rooms already reserved in each room type in each hotel will be stored in the reservations table.
The thing is the query doesn't return any result at all. Even though it should if I calculate it myself manually.
I tried running the sub-query alone and I don't get any result. And I have lost quite some amount of hair trying to de-bug this query from yesterday. What's wrong with this? Or is there a better way to do what I mentioned above?
Edit: Code edited to remove a bug. Thanks to Mark Byers.
Sample Data in reservation table
1 1 1 2 1 3 2010-03-29 2010-03-31 2010-03-17
2 1 2 3 3 8 2010-03-29 2010-03-31 2010-03-18
5 1 1 5 5 4 2010-03-29 2010-03-31 2010-03-12
The sub-query should return
Room ID : 1 Rooms Booked : 7
Room ID : 2 Rooms Booked : 8
But it does not return any value at all.... If i remove the dateCheck condition it returns
Room ID : 2 Rooms Booked : 8
Your problem is here:
$rooms.total_rooms - (SELECT SUM($reservations.no_of_rooms) as tot,
$rooms.room_id as id
FROM $reservations,$rooms
WHERE $dateCheck
GROUP BY $reservations.room_id) > '0'"
You are doing a subtraction total_rooms - (tot, id) where the first operand is a scalar value and the second is a table with two columns. Remove one of the columns in the result set and make sure you only return only one row.
You also should use the JOIN keyword to make joins instead of separating the tables with commas. That way you won't forget to add the join condition.
You probably want something along these lines:
SELECT column1, column2, etc...
FROM $hotels
JOIN $rooms
ON $hotels.hotel_id = $rooms.hotel_id
JOIN (
SELECT SUM($reservations.no_of_rooms) as tot,
$rooms.room_id as id
FROM $reservations
JOIN $rooms
ON ??? /* Aren't you missing something here? */
WHERE $dateCheck
GROUP BY $reservations.room_id
) AS T1
ON T1.id = room_id
WHERE $hotels.hotel_city = '$city_search'
AND $hotels.hotel_deleted = '0'
AND $rooms.room_deleted = '0'
AND $rooms.total_rooms - T1.tot > '0'