The project I'm asking about is for sending an email to teachers asking what books they're using for the classes they're teaching next semester, so that the books can be ordered. I have a query that compares the course number of this upcoming semester's classes to the course numbers of historical textbook orders, pulling out only those classes that are being taught this semester. That's where I get lost.
I have a table that contains the following:
Professor
Course Number
Year
Book Title
The data looks like this:
professor year course number title
--------- ---- ------------- -------------------
smith 13 1111 Pride and Prejudice
smith 13 1111 The Fountainhead
smith 13 1222 The Alchemist
smith 12 1111 Pride and Prejudice
smith 11 1222 Infinite Jest
smith 10 1333 The Bible
smith 13 1333 The Bible
smith 12 1222 The Alchemist
smith 10 1111 Moby Dick
johnson 12 1222 The Tipping Point
johnson 11 1333 Anna Kerenina
johnson 10 1333 Everything is Illuminated
johnson 12 1222 The Savage Detectives
johnson 11 1333 In Search of Lost Time
johnson 10 1333 Great Expectations
johnson 9 1222 Proust on the Shore
Here's what I need the code to do "on paper":
Group the records by professor. Determine every unique course number in that group, and group records by course number. For each unique course number, determine the highest year associated. Then spit out every record with that professor+course number+year combination.
With the sample data, the results would be:
professor year course number title
--------- ---- ------------- -------------------
smith 13 1111 Pride and Prejudice
smith 13 1111 The Fountainhead
smith 13 1222 The Alchemist
smith 13 1333 The Bible
johnson 12 1222 The Tipping Point
johnson 11 1333 Anna Kerenina
johnson 12 1222 The Savage Detectives
johnson 11 1333 In Search of Lost Time
I'm thinking I should make a record set for each teacher, and within that, another record set for each course number. Within the course number record set, I need the system to determine what the highest year number is - maybe store that in a variable? Then pull out every associated record so that if the teacher ordered 3 books the last time they taught that class (whether it was in 2013 or 2012 and so on) all three books display. I'm not sure I'm thinking of record sets in the right way, though.
My SQL so far is basic and clearly doesn't work:
SELECT [All].Professor, [All].Course, Max([All].Year)
FROM [All]
GROUP BY [All].Professor, [All].Course;
Use your query as a subquery and INNER JOIN it back to the [ALL] table to filter the rows.
SELECT
a.Professor,
a.Year,
a.Course,
a.title
FROM
[ALL] AS a
INNER JOIN
(
SELECT [All].Professor, [All].Course, Max([All].Year) AS MaxOfYear
FROM [All]
GROUP BY [All].Professor, [All].Course
) AS sub
ON
a.Professor = sub.Professor
AND a.Course = sub.Course
AND a.Year = sub.MaxOfYear;
Related
I'm ranking race data for series of cycling events. Racers win various amounts of points for their position in races. I want to retain the discrete event scoring, but also rank the racer in the series. For example, considering a sub-query that returns this:
License #
Rider Name
Total Points
Race Points
Race ID
123
Joe
25
5
567
123
Joe
25
12
234
123
Joe
25
8
987
456
Ahmed
20
12
567
456
Ahmed
20
8
234
You can see Joe has 25 points, as he won 5, 12, and 8 points in three races. Ahmed has 20 points, as he won 12 and 8 points in two races.
Now for the ranking, what I'd like is:
Place
License #
Rider Name
Total Points
Race Points
Race ID
1
123
Joe
25
5
567
1
123
Joe
25
12
234
1
123
Joe
25
8
987
2
456
Ahmed
20
12
567
2
456
Ahmed
20
8
234
But if I use rank() and order by "Total Points", I get:
Place
License #
Rider Name
Total Points
Race Points
Race ID
1
123
Joe
25
5
567
1
123
Joe
25
12
234
1
123
Joe
25
8
987
4
456
Ahmed
20
12
567
4
456
Ahmed
20
8
234
Which makes sense, since there are three "ties" at 25 points.
dense_rank() solves this problem, but if there are legitimate ties across different racers, I want there to be gaps in the rank (e.g if Joe and Ahmed both had 25 points, the next racer would be in third place, not second).
The easiest way to solve this I think would be to issue two queries, one with the "duplicate" racers eliminated, and then a second one where I can retain the individual race data, which I need for the points break down display.
I can also probably, given enough effort, think of a way to do this in a single query, but I'm wondering if I'm not just missing something really obvious that could accomplish this in a single, relatively simple query.
Any suggestions?
You have to break this into steps to get what you want, but that can be done in a single query with common table expressions:
with riders as ( -- get individual riders
select distinct license, rider, total_points
from racists
), places as ( -- calculate non-dense rankings
select license, rider, rank() over (order by total_points desc) as place
from riders
)
select p.place, r.* -- join rankings into main table
from places p
join racists r on (r.license, r.rider) = (p.license, p.rider);
db<>fiddle here
Students table
student_id student_name
1 John
2 Mary
Grades table
student_id year grade_level school Course Mark
1 2015 10 Smith High Algebra 95
1 2015 10 Smith High English 96
1 2016 11 Smith High Geometry 85
1 2016 11 Smith High Science 88
2 2015 10 Smith High Algebra 98
2 2015 10 Smith High English 93
2 2016 11 Smith High Geometry 97
2 2016 11 Smith High Science 86
I'm trying to show results for each year and what class a student took with the grade.
So the final output i'm looking for is something like:
[student_id1] [year1] [grade1] [school1]
[course1] [mark1]
[course2] [mark2]
[course3] [mark3]...
[student_id1] [year2] [grade2] [school1]
[course1] [mark1]
[course2] [mark2]
[course3] [mark3]...
[student_id2] [year1] [grade1] [school1]
[course1] [mark1]
[course2] [mark2]
[course3] [mark3]...
This would all go in one column/row. So in this particular example, this would be my result:
1 2015 10 Smith High
Algebra 95
English 96
1 2016 11 Smith High
Geometry 85
Science 88
2 2015 10 Smith High
Algebra 98
English 93
2 2016 11 Smith High
Geometry 97
Science 86
So anytime a student id, year, grade, or school name changes, I would have a line for that and loop through the classes taken within that group. And all of this would be in one column/row.
This is what I have so far but I'm not sure how I can properly loop through course and grades for each group. I'd appreciate it if I can be pointed in the right direction.
select s.student_id + '' + year + '' + grade_level + '' + school
from students
join grades on students.student_id = grades.student_id
If you want to do it in your SQL Enviromnment, it depends on the Database Management System you are using.
For example, if you are using Transact SQL you can try to look at this link.
Generally this kind of loops and interactions are done in the programming language that is coupled with the SQL DB.
Anyway, you should look at Stored Procedures and Cursors if you really want to do this in SQL.
You are trying to mix presentation with retrieval of data from database tables. Looping through the resultset in sql can be achieved via cursor but that isn't adviced. You are better off by pulling the required data using two queries and later print it using a language of your choice.
The goal is to try and obtain two random sample cases per handler ID.
The data for this project is below.
ID Complaint Handler Handler ID Reference Outcome Handler Notes
1 John Doe h384 R38423 Uphold Not Applicable
2 Ryan Jones h632 R38482 Uphold Not Applicable
3 Chris Smith h238 R84823 Defend Not Applicable
4 Emily Surry h634 R48384 Reject Not Applicable
5 Elle Smith h123 R48823 Uphold Not Applicable
6 Jane Doe h324 R48282 Uphold Not Applicable
7 Joe Bloggs h538 R83322 Reject Not Applicable
8 Ryan Jones h632 R38299 Defend Not Applicable
9 Chris Smith h238 R83482 Reject Not Applicable
10 Chris Smith h238 R91823 Reject Not Applicable
11 Joe Bloggs h538 R18291 Uphold Not Applicable
I have used the following query to select all the unique case handler references.
SELECT Cases.[Handler ID]
FROM Cases
GROUP BY Cases.[Handler ID];
I then need to loop through all these unique references and execute the following query
SELECT TOP 2 *
FROM Cases
WHERE Cases.[Handler ID] = 'XXXXXX'
ORDER BY Rnd(ID)
An example of the result would be
ID Complaint Handler Handler ID Reference Outcome Handler Notes
1 John Doe h384 R38423 Uphold Not Applicable
2 Ryan Jones h632 R38482 Uphold Not Applicable
3 Chris Smith h238 R84823 Defend Not Applicable
4 Emily Surry h634 R48384 Reject Not Applicable
5 Elle Smith h123 R48823 Uphold Not Applicable
6 Jane Doe h324 R48282 Uphold Not Applicable
7 Joe Bloggs h538 R83322 Reject Not Applicable
8 Ryan Jones h632 R38299 Defend Not Applicable
10 Chris Smith h238 R91823 Reject Not Applicable
11 Joe Bloggs h538 R18291 Uphold Not Applicable
Result example: Row 9 randomly removed as there was three Chris Smith's.
No other rows affected as there is 2 or less results.
I think this will work in MS Access:
select c.*
from cases as c
where c.id in (select top 2 c2.id
from cases as c2
where c2.handler = c.handler
order by rnd(-Timer() * c2.id)
);
how do i join following tables with wildcards? I would like to get all distinct rows from People table which contains SearchedName from SearchedPeople table.
SearchedPeople:
SearchedName
--------
Andrew
John
John Smith
People:
ID PersonName Attribute Age
----------------------------------------
1 John Smith 1 23
2 John Smith Jr 3 25
3 John Smith Jr II 4 73
4 Kevin 2 21
5 Andrew Smith 1 14
6 Marco 5 90
Desired Output:
PersonName Attribute Age
----------------------------------------
John Smith 1 23
John Smith Jr 3 25
John Smith Jr II 4 73
Andrew Smith 1 14
Code i got so far which doesnt wor. It returns three empty rows(why is that?).
SELECT b.PersonName, b.Attribute, b.Age
FROM SearchedPeople a
LEFT JOIN People b ON "%"&a.SearchedName&"%" like b.PersonName
It returns three empty rows because you don't have any columns from table a (SearchedPeople) and the LEFT JOIN didn't produce a match.
The reason is your criteria is in the wrong order you are searching for PersonName in the string %Searchedname% you need to switch that around. Also Access doesn't like the % as much as it likes the asteriks * for wilcard unless you make some changes to the query or configuration of MS-Access see below comment from Parafait.
I just tested this:
SELECT a.SearchedName
,b.PersonName, b.Attribute, b.Age
FROM
SearchedPeople a
LEFT JOIN People b
ON b.PersonName LIKE ("*" & a.SearchedName & "*")
Edit:
Good Ms Access specific information from a comment from #Parafait pasting in answer in case comment every got deleted.:
Use ALIKE and percents work. And if OP connects to MS Access via OLEDB and not the GUI .exe program, the % operator is required for LIKE statements in coded SQL. OP can also change database settings to ANSI-92 mode to always use % wildcards.
I am trying to create a view that records the selected attributes for all Computer Science majors.
This is my query to create a view:
DROP VIEW CS_grade_report;
CREATE VIEW CS_grade_report AS
SELECT Student.student_id AS "ID",
student_name AS "Name",
course_number AS "Course #",
credit AS "Credit",
grade AS Grade
FROM Student, Class, Enrolls
WHERE major = 'CSCI'
AND Student.student_id = Enrolls.student_id
AND Class.schedule_num = Enrolls.schedule_num;
SELECT *
FROM CS_grade_report;
And this is what is generated:
ID Name Course # Credit GR
------ ------------------------- -------- ---------- --
600000 John Smith CSCI3200 4 B+
600000 John Smith CSCI3700 3 C
600000 John Smith SPAN1004 3 A-
600000 John Smith CSCI4300 3 A+
600001 Andrew Tram MUSC2406 2 A+
600001 Andrew Tram SPAN1004 3 A
600001 Andrew Tram CSCI3700 3 B-
600002 Jane Doe CSCI4200 3 D+
600003 Michael Jordan CSCI4300 3 A+
600004 Tiger Woods MUSC1000 1 A
600007 Dominique Davis CSCI4300 3 F
ID Name Course # Credit GR
------ ------------------------- -------- ---------- --
600009 Will Smith CSCI3200 4 A
600010 Papa Johns CSCI3200 4 B
600011 John Doe CSCI3200 4 C
600012 Jackie Chan CSCI3200 4 D
600013 Some Guy CSCI3200 4 E
16 rows selected.
I am assuming this is output from sqlplus. There is a "pagesize" option to define when breaks are added. If you only want to see one heading, set the size to a large enough value prior to running your SELECT statement as such:
set pagesize 500
(or whatever size you want)
There are many command options for sqlplus. This link is a good cheat-sheet.