Comparing multiple rows of data in sql - sql-server-2008

Howzit guys!
I have to compare multiple rows of data with each other and i would really appreciate your help
I have a table in sql called Technicians. this table contains information about a technician such as, [Tech_id, Name, Surname, Tel, Cell, Status, Last_Available_time].
There are 3 status types: 'Available', 'Semi Available' and 'unavailable'
*Semi available meaning that a technician has jobs assigned to him but of mostly low priority. Last_available_time is set to datetime*
I need to get the technician with a status of 'available' and the longest last_available_time
I'm still a student.
My sql code:
select * from Technician
where (_Status='Available')

Just get the first record, ordered by their available date:
SELECT TOP 1 *
FROM Technician
WHERE _status = 'Available'
ORDER BY Last_Available_Time
That will give one available technician, with the oldest available time.

Related

Need to retrieve the most recent room type/Rateplan combination (mysql)

I will explain the logic:
I need to retrieve only the most recent room type/rate plan combinations from the rateplan_roomtypeTable.
room type ID and rate plan id are located in separate columns
there are 2 conditions that need to be met: all active room type/rate plan combinations need to be retrieved along with all room type/rate plan combinations that have produced even if they are not active. All these combinations need to be the most recent ones.
The desired results would be like the table I ll share with you:
Your help with the below query will be much appreciated:
select
Id
, RoomTypeId
, RateTypeId
,isactiveRateType
,isactiveRoomType
, RatePlanName
, RoomTypeName
FROM
rateplan_roomtypeTable
where
RateTypeId IN (select RateTypeId from ProductionTable where (cast(bookingdate as date) between date_add('day',-92, current_date) and date_add('day', -2, current_date)))
OR (isactiveRateType = 1 and isactiveRoomType = 1)
GROUP BY
1,2,3,4,5
Thank you

Crosstab Query on multiple data points

I have a table that tracks employee quality assessment data. It includes the employee name, 5 yes/no fields tracking important items and the date the user did each task as column headings. Each employee gets 10 records a month so it includes a lot of data about how well our employees are doing at those 5 tasks.
I would like a report that shows me the monthly averages of these 5 yes/no fields: Appeal, NRP, Churn, Protocol, and Resub. I want those to be the Row Headers. I want the column headers to be sequential Months and the Averages to be the values. I can do this with a crosstab query for a single item such as avg:Appeal as the value and the user as the row header. How can I construct my query to use all 5 yes/no fields? They hoped for result would look like:
Table image showing how I want it to look
Comments on the Correct Answer:
June7 came up with a great answer! I changed the True to False in the DataUNION query because I wanted the Accuracy percentage and the true indicates an error on the employee evaluation. I also added in a few fields I didn't mention before. Thank you very much for helping a scrub out June7! Reading through what you wrote inspired me to start taking an SQL course on Lynda. I know its basic but you have to start somewhere and I'm getting to the point where access's builtin functions aren't doing it for me. Hopefully with the next question I'll be able to address the concerns of the commentators below that were upset that I didn't have code for myself that I had tried first.
June7's revised Code
Consider:
Query1: DataUNION
SELECT ID AS SourceID, Emp, Year([TaskDate]) AS Yr, Format([TaskDate], "mmm") AS Mo, "Appeal" AS Trend
FROM Data
WHERE Appeal=True
UNION SELECT ID, Emp, Year([TaskDate]), Format([TaskDate], "mmm"), "NRP"
FROM Data WHERE NRP = True
UNION SELECT ID, Emp, Year([TaskDate]), Format([TaskDate], "mmm"), "Churn"
FROM Data WHERE Churn = True
UNION SELECT ID, Emp, Year([TaskDate]), Format([TaskDate], "mmm"), "Protocol"
FROM Data WHERE Protocol = True
UNION SELECT ID, Emp, Year([TaskDate]), Format([TaskDate], "mmm"), "Resub"
FROM Data WHERE Resub = True;
Query2: DataCOUNT
SELECT DataUNION.Yr, DataUNION.Mo, DataUNION.Trend,
Count(DataUNION.Emp) AS CountOfEmp, Q.CntYrMo, Count([Emp])/[CntYrMo]*100 AS Pct
FROM (SELECT Year([TaskDate]) AS Yr, Format([TaskDate],"mmm") AS Mo, Count(Data.ID) AS CntYrMo
FROM Data
GROUP BY Year([TaskDate]), Format([TaskDate],"mmm")) AS Q
INNER JOIN DataUNION ON (Q.Yr = DataUNION.Yr) AND (Q.Mo = DataUNION.Mo)
GROUP BY DataUNION.Yr, DataUNION.Mo, DataUNION.Trend, Q.CntYrMo;
Query3:
TRANSFORM First(DataCount.Pct) AS FirstOfPct
SELECT DataCount.Yr, DataCount.Trend
FROM DataCount
GROUP BY DataCount.Yr, DataCount.Trend
PIVOT DataCount.Mo In ("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");

Relational Database Logic

I'm fairly new to php / mysql programming and I'm having a hard time figuring out the logic for a relational database that I'm trying to build. Here's the problem:
I have different leaders who will be in charge of a store anytime between 9am and 9pm.
A customer who has visited the store can rate their experience on a scale of 1 to 5.
I'm building a site that will allow me to store the shifts that a leader worked as seen below.
When I hit submit, the site would take the data leaderName:"George", shiftTimeArray: 11am, 1pm, 6pm (from the example in the picture) and the shiftDate and send them to an SQL database.
Later, I want to be able to get the average score for a person by sending a query to mysql, retrieving all of the scores that that leader received and averaging them together. I know the code to build the forms and to perform the search. However, I'm having a hard time coming up with the logic for the tables that will relate the data. Currently, I have a mysql table called responses that contains the following fields,
leader_id
shift_date // contains the date that the leader worked
shift_time // contains the time that the leader worked
visit_date // contains the date that the survey/score was given
visit_time // contains the time that the survey/score was given
score // contains the actual score of the survey (1-5)
I enter the shifts that the leader works at the beginning of the week and then enter the survey scores in as they come in during the week.
So Here's the Question: What mysql tables and fields should I create to relate this data so that I can query a leader's name and get the average score from all of their surveys?
You want tables like:
Leader (leader_id, name, etc)
Shift (leader_id, shift_date, shift_time)
SurveyResult (visit_date, visit_time, score)
Note: omitted the surrogate primary keys for Shift and SurveyResult that I would probably include.
To query you join shifts and surveys group on leader and taking the average then jon that back to leader for a name.
The query might be something like (but I haven;t actually built it in MySQL to verify syntax)
SELECT name
,AverageScore
FROM Leader a
INNER JOIN (
SELECT leader_id
, AVG(score) AverageScore
FROM Shift
INNER JOIN
SurveyResult ON shift_date = visit_date
AND shift_time = visit_time --depends on how you are recording time what this really needs to be
GROUP BY leader ID
) b ON a.leader_id = b.leader_id
I would do the following structure:
leaders
id
name
leaders_timetabke (can be multiple per leader)
id,
leader_id
shift_datetime (I assume it stores date and hour here, minutes and seconds are always 0
survey_scores
id,
visit_datetime
score
SELECT l.id, l.name, AVG(s.score) FROM leaders l
INNER JOIN leaders_timetable lt ON lt.leader_id = l.id
INNER JOIN survey_scores s ON lt.shift_datetime=DATE_FORMAT('Y-m-d H:00:00', s.visit_datetime)
GROUP BY l.id
DATE_FORMAT here helps to cut hours and minutes from visit_datetime so that it could be matched against shift_datetime. This is MYSQL function, so if you use something else you'll need to use different function
Say you have a 'leader' who has 5 survey rows with scores 1, 2, 3, 4 and 5.
if you select all surveys from this leader, sum the survey scores and divide them by 5 (the total amount of surveys that this leader has). You will have the average, in this case 3.
(1 + 2 + 3 + 4 + 5) / 5 = 3
You wouldn't need to create any more tables or fields, you have what you need.

MySQL - The most occuring for the specific day?

I'm stuck on this problem.
Basically I need to find out for each department how to figure out which days had the most sales made in them. The results display the department number and the date of the day and a department number can appear several times in the results if there were several days that have equally made the most sales.
This is what I have so far:
SELECT departmentNo, sDate FROM Department
HAVING MAX(sDate)
ORDER BY departmentNo, sDate;
I tried using the max function to find which dates occurred most. But it only returns one row of values. To clarify more, the dates that has the most sales should appear with the corresponding column called departmentNo. Also, if two dates for department A has equal amount of most sales then department A would appear twice with both dates showing too.
NOTE: only dates with the most sales should appear and the departmentNo.
I've started mySQL for few weeks now but still struggling to grasp the likes of subqueries and store functions. But i'll learn from experiences. Thank you in advance.
UPDATED:
Results I should get:
DepartmentNo Column 1: 1 | Date Column 2: 15/08/2000
DepartmentNo Column 1: 2 | Date Column 2: 01/10/2012
DepartmentNo Column 1: 3 | Date Column 2: 01/06/1999
DepartmentNo Column 1: 4 | Date Column 2: 08/03/2002
DepartmentNo Column 1: nth | Date Column 2: nth date
These are the data:
INSERT INTO Department VALUES ('1','tv','2012-05-20','13:20:01','19:40:23','2');
INSERT INTO Department VALUES ('2','radio','2012-07-22','09:32:23','14:18:51','4');
INSERT INTO Department VALUES ('3','tv','2012-09-14','15:15:43','23:45:38','3');
INSERT INTO Department VALUES ('2','tv','2012-06-18','06:20:29','09:57:37','1');
INSERT INTO Department VALUES ('1','radio','2012-06-18','11:34:07','15:41:09','2');
INSERT INTO Department VALUES ('2','batteries','2012-06-18','16:20:01','23:40:23','3');
INSERT INTO Department VALUES ('2','remote','2012-06-18','13:20:41','19:40:23','4');
INSERT INTO Department VALUES ('1','computer','2012-06-18','13:20:54','19:40:23','4');
INSERT INTO Department VALUES ('2','dishwasher','2011-06-18','13:20:23','19:40:23','4');
INSERT INTO Department VALUES ('3','lawnmower','2011-06-18','13:20:57','20:40:23','4');
INSERT INTO Department VALUES ('3','lawnmower','2011-06-18','11:20:57','20:40:23','4');
INSERT INTO Department VALUES ('1','mobile','2012-05-18','13:20:31','19:40:23','4');
INSERT INTO Department VALUES ('1','mouse','2012-05-18','13:20:34','19:40:23','4');
INSERT INTO Department VALUES ('1','radio','2012-05-18','13:20:12','19:40:23','4');
INSERT INTO Department VALUES ('2','lawnmowerphones','2012-05-18','13:20:54','19:40:23','4');
INSERT INTO Department VALUES ('2','tv','2012-05-12','06:20:29','09:57:37','1');
INSERT INTO Department VALUES ('2','radio','2011-05-23','11:34:07','15:41:09','2');
INSERT INTO Department VALUES ('1','batteries','2011-05-21','16:20:01','23:40:23','3');
INSERT INTO Department VALUES ('2','remote','2011-05-01','13:20:41','19:40:23','4');
INSERT INTO Department VALUES ('3','mobile','2011-05-09','13:20:31','19:40:23','4');
For department1 the date 2012-05-18 would appear because that date occurred the most. And for every department, it should only show the one with the most sales, and if same amount of sales appears on the same date then both will appear, e.g. Department 1 will appear twice with both the dates of max sales.
I've tested the following query based on the table and two columns you've provided along with sample data. So, let me describe it for you. The inner-most "PREQUERY" is doing a count by department and date. The results of this will be pre-ordered by Department first, THEN the highest count in DESCENDING ORDER (so highest sales count is listed FIRST), it doesn't matter what date the count happened.
Next, by utilizing MySQL #variables, I'm pre-declaring two to be used in the query. #variables are like inline programming with MySQL. They can be declared once and then changed as applied to each record being processed. So, I'm defaulting to a bogus department value and a zero sales count.
Now, I'm grabbing the results of the PreQuery (Dept, #Sales and Date), but now, adding a test. If it is the FIRST ENTRY for a given department, use that record's "NumberOfSales" and put into the #maxSales variable and store as a final column name "MaxSaleCnt". The next column name uses the #lastDept and is set to whatever the current record's Department # is. So it can be compared to the next record.
If the next record is the same department, then it just keeps whatever the #maxSales value was from the previous, thus keeping the same first count(*) result for ALL entries on each respective department.
Now, the closure. I've added a HAVING clause (not a WHERE as that restricts what records get tested, but HAVING processes AFTER the records are part of the PROCESSED set. So now, it would have all 5 columns. I am saying ONLY KEEP those records where the final NumberOfSales for the record MATCHES the MaxSaleCnt for the department. If one, two or more dates, no problem it returns them all per respective department.
So, one department could have 5 dates with 10 sales each, and another department has 2 dates with only 3 sales each, and another with only 1 date with 6 sales.
select
Final.DepartmentNo,
Final.NumberOfSales,
Final.sDate
from
(select
PreQuery.DepartmentNo,
PreQuery.NumberOfSales,
PreQuery.sDate,
#maxSales := if( PreQuery.DepartmentNo = #lastDept, #maxSales, PreQuery.NumberOfSales ) MaxSaleCnt,
#lastDept := PreQuery.DepartmentNo
from
( select
D.DepartmentNo,
D.sDate,
count(*) as NumberOfSales
from
Department D
group by
D.DepartmentNo,
D.sDate
order by
D.DepartmentNo,
NumberOfSales DESC ) PreQuery,
( select #lastDept := '~',
#maxSales := 0 ) sqlvars
having
NumberOfSales = MaxSaleCnt ) Final
To clarify the "#" and "~" per you final comment. The "#" indicates a local variable to the program (or in this case and in-line sql variable) that can be used in the query. The '~' is nothing more than a simple string that probability would never exist that of any of your departments, so when it is compared to the first qualified record, does an IF( '~' = YourFirstDepartmentNumber, then use this answer, otherwise use this answer).
Now, how do the above work. Lets say the following is the results of your data returned by the inner-most query, grouped and ordered by the most sales at the top going down... SLIGHTLY altered from your data, lets just assume the following to simulate multiple dates on Dept 2 that have the same sales quantity...
Row# DeptNo Sales Date # Sales
1 1 2012-05-18 3
2 1 2012-06-18 2
3 1 2012-05-20 1
4 2 2012-06-18 4
5 2 2011-05-23 4
6 2 2012-05-18 2
7 2 2012-05-12 1
8 3 2011-06-18 2
9 3 2012-09-14 1
Keep track of the actual rows. The innermost query that finishes as alias "PreQuery" returns all the rows in the order you see here. Then, that is joined (implied) with the declarations of the # sqlvariables (special to MySQL, other sql engines dont do this) and starts their values with the lastDept = '~' and the maxSales = 0 (via assignment with #someVariable := result of this side ).
Now, think of the above being handled as a
DO WHILE WE HAVE RECORDS LEFT
Get the department #, Number of Sales and sDate from the record.
IF the PreQuery Record's Department # = whatever is in the #lastDept
set MaxSales = whatever is ALREADY established as max sales for this dept
This basically keeps the MaxSales the same value for ALL in the same Dept #
ELSE
set MaxSales = the # of sales since this is a new department number and is the highest count
END IF
NOW, set #lastDept = the department you just processed to it
can be compared when you get to the next record.
Skip to the next record to be processed and go back to the start of this loop
END DO WHILE LOOP
Now, the reason you need to have the #MaxSales and THEN the #LastDept as returned columns is they must be computed for each record to be used to compare to the NEXT record. This technique can be used for MANY application purposes. If you click on my name, look at my tags and click on the MySQL tag, it will show you the many MySQL answers I've responded to. Many of them do utilize # sqlvariables. In addition, there are many other people who are very good at working queries, so dont just look in one place. As for any question, if you find a good answer that you find helpful, even if you didn't post the question, clicking on an up-arrow next to the answer helps others indicate what really helped them understand and get resolution to questions -- again, even if its not your question. Good luck on your MySQL growth.
I think this can be achieved with a single query, but my experiences for similar functionality have involved either WITH (as defined in SQL'99) using either Oracle or MSSQL.
The best (only?) way to approach a problem like this is to break in into smaller components. (I don't think your provided statement provides all columns, so I'm going to have to make a few assumptions.)
First, how many sales were made for each day for each group:
SELECT department, COUNT(1) AS dept_count, sale_date
FROM orders
GROUP BY department, sale_date
Next, what's the most sales for each department
SELECT tmp.department, MAX(tmp.dept_count)
FROM (
SELECT department, COUNT(1) AS dept_count
FROM orders
GROUP BY department
) AS tmp
GROUP BY tmp.department
Finally, putting the two together:
SELECT a.department, a.dept_count, b.sale_date
FROM (
SELECT tmp.department, MAX(tmp.dept_count) AS max_dept_count
FROM (
SELECT department, COUNT(1) AS dept_count
FROM orders
GROUP BY department
) AS tmp
GROUP BY tmp.department
) AS a
JOIN (
SELECT department, COUNT(1) AS dept_count, sale_date
FROM orders
GROUP BY department, sale_date
) AS b
ON a.department = b.department
AND a.max_dept_count = b.dept_count

Microsoft Access 2010 - Filtering by a caculated field in a query-based report

Ok, here's the condensed form. I have three main tables to draw data from:
StudentData - PK is the student's ID Number. Contains contact info, their current status ('00' for none, 'P' for Probation, 'S' for Suspension), and cumulative gpa data.
CourseData - PK is the CRN. Contains just the abbreviated subject and the course number (IE ECON 200)
StudentCourses - PK is an AutoNum. Many-to-Many relationship table between StudentData and CourseData. Also contains stats for the particular student's class (grade, credit hours, etc).
So some sample data would look like:
-
StudentData
ID: 12345678
Name: John Doe; ...[Other contact info]; 00; CumCreditHours: 100; CumCoursePoints: 190
-
CourseData
CRN: 0001; Abbrev: ECON; CourseNumber: 101
CRN: 0002; Abbrev: CSCI; CourseNumber 201
-
StudentCourses
AutoNum: 1
StudentID: 12345678; CRN: 0001; Grade: A-; Credits: 3
AutoNum: 2
StudentID 12345678; CRN: 0002; Grade: B; Credits: 3
-
At this point, this is how I have things set up:
First, a query runs that finds all of the courses a student takes and converts the letter grades into a point value. Another query based on the first sums the point totals and the credit hours. A third query takes those totals and calculates the GPA by dividing their point total by the credit hour total.
Separately, a query runs that calculates the student's cumulative GPA by taking their cumulative points and hours from the StudentData table (again dividing the points by the hours).
Then, another query takes both the semester GPA, cumulative GPA, current status, and cumulative credit hours and calculates the recommended action for the student. So for our example data it would look like:
_
SemesterGPA: 3.33; CumulativeGPA: 1.90; CurrentStatus: 00; CumulativeCreditHours: 100
_
I have the formula to determine their recommended action set up as a series of nested IIF statements that looks like:
IIf([CurrentStatus]="00" And [CumulativeGPA]<2 And [CumulativeCreditHours]>=12 And [CumulativeCreditHours]<=23,"PFY",IIf([CurrentStatus]="00" And [CumulativeGPA]>=1.7 And [CumulativeGPA]<=1.99 And [CumulativeCreditHours]>=24,"P",IIf([CurrentStatus]="00 " And [CumulativeGPA]<2 And [SemesterGPA]<2 And [CumulativeCreditHours]<12,"W",IIf([CurrentStatus]="00" And [CumulativeGPA]>=2 And [CumulativeGPA]<=2.5 And [SemesterGPA]<2 And [CumulativeCreditHours]>=12,"WUP",IIf([CurrentStatus]="00" And [CumulativeGPA]<1.7 And [CumulativeCreditHours]>=24,"SUSP",IIf([CurrentStatus]="P" And [CumulativeGPA]<2 And [SemesterGPA]>=2 And [CumulativeCreditHours]>=12,"CP",IIf([CurrentStatus]="P" And [CumulativeGPA]>=2 And [SemesterGPA]<2 And [CumulativeCreditHours]>=12,"SPCP",IIf([CurrentStatus]="P" And [CumulativeGPA]>=2 And [CumulativeCreditHours]>=12,"RP",IIf([CurrentStatus]="P" And [CumulativeGPA]<2 And [SemesterGPA]<2 And [CumulativeCreditHours]>=12,IIf(IsNull([PriorSuspension]),"S(FD)","D(SD)"),"None")))))))))
For our example, John Doe's recommended action would be 'P' since his current status is 00, he has over 24 cumulative credits, and his cumulative gpa is between 1.7 and 1.99.
Now for the problem: I would like to be able to make a report that can filter by the recommended action. I've detailed the issues I've had previously, but in short, the way I have the reports set up now (with the information being displayed in a sub-report inside a report that is based on the StudentData table to provide the aforementioned queries with the StudentID) doesn't allow me to do this because the field I want to filter by exists in the sub-report and not the main report (and you can't set the filter properties for a sub-report).
Any ideas?
Ok, I've got this to work now. I realized that as I was calculating the semester GPAs that I had grouped the results together by ID at some point during the process. This allowed me to remove the part of the initial query that grabbed the ID number from the form. Since the last query in the process linked everything together by student ID, the individual records held all of the information I needed and everything fell into place after that.
I half expected something simple like this to be the answer to my problem, but I'm still disappointed that it took me this long to figure it out...
Anyway, thanks to anyone who might have been thinking of possible solutions for this problem.